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blairgowrie
11-23-2009, 09:07 AM
Continued from: http://forums.ubi.com/eve/foru...711006608#8711006608 (http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/2731072208?r=8711006608#8711006608)

BillSwagger
11-23-2009, 09:41 AM
The fuel goes where gravity takes it.

So what you are saying is that for fuel to leak from the tank in the fuselage into the wing, the plane would then need to bank to that side.

If the plane is turning it would also follow the G force, which would also send fuel toward the belly of the plane.


And just to clarify, its the bladders that are self sealing, not the bay that they are placed in.

what would keep the fuel that leaks from a projectile, from just puddling up in the storage bay?

Isn't that fuel bay sealed off, or is that also vented?



From the other diagrams posted, i still don't see how fuel can leak to near wing and explode, and not also cause a far in other sections of the plane where fumes, or fuel has accumulated.

Shouldn't we be seeing more fire from fuel burning off, after the explosion?



Bill

JtD
11-23-2009, 10:00 AM
As I've stated before, if fuel was flowing through the aircraft the plane would blow up as it takes off. Fuel fumes form much easier on the hot ground, with no venting going on, than in cool air up high with lots of venting going on. There's a large number of ignition sources in the take off process, which almost guarantee the explosion if it ever was to occur.

Also, considering this ongoing explosion a fuel vapour explosion is pretty much offensive to anyones intellect, fuel vapour goes off at once, belted ammo, however, may not:

http://mitglied.lycos.de/jaytdee/snapshot.JPG

yuuppers
11-23-2009, 10:27 AM
With the 190 sitting on the ground, or in a climbing attitude, any fuel leakage would run to the tail where the electric motor for the tail trim could ignite the fuel.

In a dive, the fuel would run towards the very hot engine and be ignited.

Of course, the panel under the fuel tanks of the 190 was completely sealed allowing no seepage.

virgule88
11-23-2009, 10:31 AM
Posting the link to the original thread's footage for the convenience of all:

http://video.google.com/videop...8324640976189633970# (http://video.google.com/videoplay?docid=8324640976189633970#)

Bremspropeller
11-23-2009, 11:23 AM
http://www.youtube.com/watch?v=XkAlwB77nIs

Fuel vapor explosion.

TS_Sancho
11-23-2009, 11:50 AM
Good job Bill, its been awhile since the mods have encouraged a "regular thread, part 2".


Liquid gasoline doesn't explode it burns rather slowly, gasoline vapors mixed with atmosphere makes great explosions. Look at combustion engines. The explosive potential of gasoline was covered earlier and I don't think anyone disputes that a few ounces of gas properly atomized makes for a big boom.

With the FW190 the whole back half of the wing at the fuselage is next to the fuel tank, and the part of the wing we keep seeing fail is only a few feet away. Shrapnel damage to the fuel tank aside its not a leap of faith to to think that fuel vapors from basic operation would collect in the area (mechanical things leak, its just the way it is). As to the wing being vented, we all know fluid dynamics are complicated. You could just as easily say that airflow leaking into the structure would help atomize the fuel, that pressure helps fuel air explosions to be more effecient.

The area we are seeing the wings blow apart doesn't have to be the source of the ignition, its only where we are seeing the structure fail first. There are coincidently holes in the wingspar in the same place the wings are failing in the videos(The gear strut is attached there with the cannon barrel passing through the spar right next to it.) It would seem that the wing is predisposed to break in the in a lot of different situations, not only internal explosions.

I think its clear detonation of the ammunition magazines is possible and happened, I don't understand the reluctance to believe that fuel explosions, by their nature, would be at least as probable.

BaronUnderpants
11-23-2009, 12:08 PM
Originally posted by TS_Sancho:
Good job Bill, its been awhile since the mods have encouraged a "regular thread, part 2".


Liquid gasoline doesn't explode it burns rather slowly, gasoline vapors mixed with atmosphere makes great explosions. Look at combustion engines. The explosive potential of gasoline was covered earlier and I don't think anyone disputes that a few ounces of gas properly atomized makes for a big boom.

With the FW190 the whole back half of the wing at the fuselage is next to the fuel tank, and the part of the wing we keep seeing fail is only a few feet away. Shrapnel damage to the fuel tank aside its not a leap of faith to to think that fuel vapors from basic operation would collect in the area (mechanical things leak, its just the way it is). As to the wing being vented, we all know fluid dynamics are complicated. You could just as easily say that airflow leaking into the structure would help atomize the fuel, that pressure helps fuel air explosions to be more effecient.

The area we are seeing the wings blow apart doesn't have to be the source of the ignition, its only where we are seeing the structure fail first. There are coincidently holes in the wingspar in the same place the wings are failing in the videos(The gear strut is attached there with the cannon barrel passing through the spar right next to it.) It would seem that the wing is predisposed to break in the in a lot of different situations, not only internal explosions.

I think its clear detonation of the ammunition magazines is possible and happened, I don't understand the reluctance to believe that fuel explosions, by their nature, would be at least as probable.


Because if it was as probable it would mean that the ac in question (Fw in this case) DOESNT have a major flaw in its design/equipment, it would only mean that something happend that could happen to any airplane shot at.


Not nearly as intresting http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

M_Gunz
11-23-2009, 12:19 PM
I would think that a few shots through the fuel tank or a fuel line would increase the chances of such
an explosion soon after far and above normal undamaged operations. Fumes alone can go from fuselage
into wing unless it is sealed. Where will the explosion be seen? Any place weak enough to blow open?
Any place damaged enough to be weaker?

Could be fumes, could be ammo, could be fuel tank?

Where they make gunpowder or fireworks there's usually one weak wall that will blow out before the others
to keep an accidental blast from taking out adjacent assets. The old DuPont works had the weaker wall
facing out on the river I saw for instance. It's an engineering thing like having a part that will break
before something much more expensive or dangerous will, at least hopefully. I wonder if they did that
with the planes for any of those explosive kind of things? I'm guessing not but it's maybe worth asking.

M_Gunz
11-23-2009, 12:30 PM
Just saw the end of the original thread. Bill, get a copy of the MGM BoB film from 1968! They simulate a few
delayed fuel explosions and fires, and check the list of technical advisers while you're at it. Got my copy
at Target for $10 a few years ago and worth more than it cost. I dunno if those planes had the self-sealing
tanks or not and no, while not perfect it's not your usual hollyweird extravaganza like that last Pearl Harbor
movie (read: crock of feces), more like Tora-Tora-Tora which was also done with good attention to historic detail.

RegRag1977
11-23-2009, 12:46 PM
Originally posted by JtD:
As I've stated before, if fuel was flowing through the aircraft the plane would blow up as it takes off. Fuel fumes form much easier on the hot ground, with no venting going on, than in cool air up high with lots of venting going on. There's a large number of ignition sources in the take off process, which almost guarantee the explosion if it ever was to occur.

Also, considering this ongoing explosion a fuel vapour explosion is pretty much offensive to anyones intellect, fuel vapour goes off at once, belted ammo, however, may not:

http://mitglied.lycos.de/jaytdee/snapshot.JPG

Yes , but as the attacking pilot is still shooting the smoke (puffs) could also come from the burst's impacting shells on the remains of the broken wing ( i mean the part of the wing which is still attached to the fuselage). It looks like a stream of puffs to me, not detonating shells.

.

Gibbage1
11-23-2009, 12:50 PM
I still dont understand the logic behind the fume theries. Lets take a look at the fumes promosed path.

http://www.gibbageart.com/files/dm/fw190wing.jpg

The two fuel tanks are located under the cockpit below the pilots seat. AFT of the wing. A good 4-5 feet away from the location of the explosions.

First, thats a fair distance for fumes to travel. Not only does it need to move apposed to the direction of the aircraft (forward) but also make a 90 degree turn and travel out and UP a wing with dihedral. Fumes are heavier then air, so thus would want to travel back and down, out the tail.

Lets talk about obsticals.

http://fw190.hobbyvista.com/sa190d.jpg

Here is the wheel well. First, most 190's didnt have the inner wheel cover. They were open. Lots of air flow. Also, look at the gun port, open holes. To the right of that, a big hole through the main spar. Again, more air flow. Then look at the drawing above. The the gun heat lines. So its enducing more air into the wing cavity. To do that, air needs to come out, or you get back pressure. The result is no heat, or blown panels. So the wing is very well vented. To have fumes travel that far, up hill, apposed to air flow, in a well vented wing? Seriously?

Then, lets not forget about the two operational cannon's in each wing. IF there was some type of really critical design flaw that ALLOWED fumes to gather in the wings, wouldent normal operation of a CANNON ignight the fumes? Are you really suggesting that the great German engineers would overlook such a design flaw that could detonate the aircraft just pulling the trigger?

The fuel vapor therie is so far fetched, it makes the 20MM ammo detonation look like a near enevitable event compaired to it.

JtD
11-23-2009, 12:58 PM
Originally posted by RegRag1977:

Yes , but as the attacking pilot is still shooting the smoke (puffs) could also come from the burst's impacting shells on the remains of the broken wing ( i mean the part of the wing which is still attached to the fuselage). It looks like a stream of puffs to me, not detonating shells.

If you look closely at the video, you'll find not only one major initial explosion far larger than a 20mm may manage, you'll also find that a few of the remaining puffs shoot out of the wings ripped open end. You can actually see one on this poor image I've posted, the white puff at the wings trailing edge just shot out of the wing. This would not happen if the puffs came from 20mm hits fired from the chasing plane.

The guy would also have to be the best gunner on earth. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Bremspropeller
11-23-2009, 01:16 PM
The two fuel tanks are located under the cockpit below the pilots seat. AFT of the wing.

Sure?

http://www.cockpitinstrumente.de/Flugzeuge/J%E4ger/Fw190A3/cockpit/gross/laengsschnitt.jpg

You certainly haven't heard what vortices and flow-separations do to gasses, have you?

Does flow-reversal ring a bell?
Mixing/ increase of entropy?


First, thats a fair distance for fumes to travel. Not only does it need to move apposed to the direction of the aircraft (forward) but also make a 90 degree turn and travel out and UP a wing with dihedral.

Like a fluid, fumes are capable of doing just that.


IF there was some type of really critical design flaw

Why does it have to be a design flaw?
- Bad maintenance?
- A hole in the tank by a bullet that went through a couple of minutes earlier?
- Structural overstress


Are you really suggesting that the great German engineers would overlook such a design flaw that could detonate the aircraft just pulling the trigger?

Are you suggesting the great Boeing-engineers overlooked a design flaw that would blow up two different center wing-tanks?


The fuel-fume theory is not that much of a far cry if you really think about it.

TS_Sancho
11-23-2009, 01:18 PM
The two fuel tanks are located under the cockpit below the pilots seat. AFT of the wing.

I need to scan and post the FW cut away I'm looking at. It clearly shows the forward underfloor fuel tank begining at a point inline with the rudder pedals, close to the center of the wing and the main underfloor fuel tank ending at the same bulkhead the radio is attatched to (which is about even with the point where the rear edge of the wing fairing blends into the fuselage.)

Edit... TY Brems. I have a different diagram but it shows the same placement.

Kettenhunde
11-23-2009, 01:21 PM
You can see where all the slime from the firewall forward goes...

Clean as a whistle!

http://img339.imageshack.us/img339/447/190andmodel1.jpg (http://img339.imageshack.us/i/190andmodel1.jpg/)


Belly pan removed to get to the fuel tanks...

http://img214.imageshack.us/img214/7533/fueltank.jpg (http://img214.imageshack.us/i/fueltank.jpg/)


Belly pan in Gibbages photo.

http://img214.imageshack.us/img214/5113/sa190.jpg (http://img214.imageshack.us/i/sa190.jpg/)


So what is it you do with airplanes again, Gibbage?

Kettenhunde
11-23-2009, 01:33 PM
So nobody gets confused as to what we are looking at....

http://img26.imageshack.us/img26/2707/fueltank2.jpg (http://img26.imageshack.us/i/fueltank2.jpg/)

Gibbage1
11-23-2009, 02:00 PM
Originally posted by Bremspropeller:
Are you suggesting the great Boeing-engineers overlooked a design flaw that would blow up two different center wing-tanks?


The fuel-fume theory is not that much of a far cry if you really think about it.

Fumes in fuel tanks is rather likley. Fumes in a vented wing without fuel tanks not likley. Try again.

Yes, I was wrong about the location of the wings vs the fuel tanks. Im at work, and dont have access to my resources. At least I can admit that, and not go back and edit my post's to cover it up. That still does not explain away the other point. Distance through a vented wing.

psykopatsak
11-23-2009, 02:08 PM
for fuel to trave all that far, there need to be a flow, otherwise fumes stay pretty mugh put. so, if the fumes would somehow get all the way to the cannon, then it would be because it was sucked out of the aircraft that way.

Gibbage1
11-23-2009, 02:14 PM
Originally posted by psykopatsak:
for fuel to trave all that far, there need to be a flow, otherwise fumes stay pretty mugh put. so, if the fumes would somehow get all the way to the cannon, then it would be because it was sucked out of the aircraft that way.

Wouldent it be hard to gather if it was being sucked out? Also, from what I see, the FW A series uses fumes from the exhaust, so the area is filled with CO2 and little O2. Again, another bocking factor for the fume therie.

Kettenhunde
11-23-2009, 02:14 PM
in a vented wing

Here is a concept to ponder...leakage drag....

http://forums.ubi.com/images/smilies/partyhat.gif

BillSwagger
11-23-2009, 02:28 PM
The fuel goes where gravity takes it.

So what you are saying is that for fuel to leak from the tank in the fuselage into the wing, the plane would then need to bank to that side.

If the plane is turning it would also follow the G force, which would also send fuel toward the belly of the plane.


And just to clarify, its the bladders that are self sealing, not the bay that they are placed in.

what would keep the fuel that leaks from a projectile, from just puddling up in the storage bay?

Isn't that fuel bay sealed off, or is that also vented?



From the other diagrams posted, i still don't see how fuel can leak to near mid wing and explode, and not also cause a fire in other sections of the plane where fumes, or fuel has accumulated.

Shouldn't we be seeing more fire from fuel burning off, after the explosion?



Bill

Bremspropeller
11-23-2009, 02:50 PM
Also, from what I see, the FW A series uses fumes from the exhaust, so the area is filled with CO2 and little O2. Again, another bocking factor for the fume therie.


Wouldn't that stand in contrast to your proposed "vented" wing?

Gibbage1
11-23-2009, 02:53 PM
Originally posted by Bremspropeller:
Wouldn't that stand in contrast to your proposed "vented" wing?

No. If your pumping air into a wing, it needs to exit some place, thus venting. Also, when a cannon is fired, gases are also dumped into the wing. Those gases need to also be vented out.

This is really really basic stuff here. I dont see how your not understanding it.

Kettenhunde
11-23-2009, 02:55 PM
the bladders that are self sealing, not the bay that they are placed in.

That is correct.


Isn't that fuel bay sealed off, or is that also vented?

It is just a thin sheet of aircraft aluminum and the structure is not water or air tight on the interior like all airplanes..

The Smithsonian even gave us some original C3 fuel to dump on the floor of the cockpit so the airplane would smell authentic when flown....

Kettenhunde
11-23-2009, 02:59 PM
Wouldn't that stand in contrast to your proposed "vented" wing?

The heating system has been drug into this as a reason the bilge was not combustible...

http://forums.ubi.com/images/smilies/partyhat.gif

How did that make the conspiracy theory list?

TS_Sancho
11-23-2009, 03:05 PM
The Smithsonian even gave us some original C3 fuel to dump on the floor of the cockpit so the airplane would smell authentic when flown....

On one of the mechanics at the Boeing Flight Museum restoration center in Seattle told me that the German fuel had sweet smell like tolulene, is that true?

Daiichidoku
11-23-2009, 03:21 PM
Originally posted by TS_Sancho:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Smithsonian even gave us some original C3 fuel to dump on the floor of the cockpit so the airplane would smell authentic when flown....

On one of the mechanics at the Boeing Flight Museum restoration center in Seattle told me that the German fuel had sweet smell like tolulene, is that true? </div></BLOCKQUOTE>

http://www.youtube.com/watch?v=RXtePW4v8zs

Gibbage1
11-23-2009, 03:50 PM
Originally posted by TS_Sancho:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The Smithsonian even gave us some original C3 fuel to dump on the floor of the cockpit so the airplane would smell authentic when flown....

On one of the mechanics at the Boeing Flight Museum restoration center in Seattle told me that the German fuel had sweet smell like tolulene, is that true? </div></BLOCKQUOTE>

I wonder what the shelf life of 60 year old German AV gas is. All I know is if I store my bike for any longer then a few weeks, I need to add fuel stabilizer. 60 years? I wonder if it even still smells like it did.

Kettenhunde
11-23-2009, 03:56 PM
On one of the mechanics at the Boeing Flight Museum restoration center in Seattle told me that the German fuel had sweet smell like tolulene, is that true?

I don't know. We have it sealed up and I have never even seen the jar.

I was told it smells like tar and has a very oily consistency. It is closer to a light oil than what we think of as gasoline.

BillSwagger
11-23-2009, 04:00 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">the bladders that are self sealing, not the bay that they are placed in.

That is correct.


Isn't that fuel bay sealed off, or is that also vented?

It is just a thin sheet of aircraft aluminum and the structure is not water or air tight on the interior like all airplanes..

The Smithsonian even gave us some original C3 fuel to dump on the floor of the cockpit so the airplane would smell authentic when flown.... </div></BLOCKQUOTE>

so whats to keep a puncture in the fuel tank from just spilling out the bottom of the plane ?

I'm also aware that these bladders build up pressure, not only from altitude change, but because the viscosity of the gas as well as expansion from changes in temperature.

A puncture is likely to push a lot of fuel and/or fumes through the puncture of the bag (for what did we say earlier 10-15 seconds, source?)

An explosion in mid wing doesn't account for this.

however, i point to the footage beginning at 0:05,
http://video.google.com/videop...8324640976189633970# (http://video.google.com/videoplay?docid=8324640976189633970#)

Pay particular attention to the amount of fire, and not to mention, the location of this explosion.

This particular explosion might have been the result of ignition as the puncture occurred, or immediately after. (with in that 10-15 second window)

If we are too speculate that the other planes in the footage received prior damage causing spillage into different areas, it might also be necessary to nail down these facts surrounding how fast they seal. That is a matter of determining how much fuel is likely to be sprayed inside the fuel bay. Doing so is probably moot.


I still can't gather that the explosion in mid wing wouldn't also ignite this fuel that's recently been sprayed out of the rupture in the fuel bladder.



Bill

Gibbage1
11-23-2009, 04:11 PM
Thats true. If there was enough vapor in the wing to ignight, then there would be a trail of vapor leading to the source, the fuel tank, or the pile of gas in the belly. But, only the wing explodes, not the belly, or any other part for that matter.

BillSwagger
11-23-2009, 04:32 PM
For all tense and purposes that particular sequence is too short and too fuzzy to make any assertions about the sequence of the explosion.

What i do see is a fire ball, which is absent in the other shots. I would outline where i think the aircraft is located in red, but the argument is moot.
In the last second of the frame there doesn't appear to be much of a plane in tact at all, other than the opposite wing, remaining spars that pass through the fuselage, as well as some wire framing, which i can only speculate, is still attached to the engine This allows for a significant center of gravity in which the wing to pivot from.

It would take much higher definition, and FPS in that sequence to see what is happening in 2 seconds of footage.
It sort of like debating over what an impressionistic painting is supposed to represent. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

yuuppers
11-23-2009, 04:48 PM
In this discussion it is nice to some people, like Bill and Gibbage, are open minded while others have a closed mind single dimensional thought process.

Gibbage here is another source of wing venting, the cover for the wing root cannons. Also note the hole near the trailing edge.

http://www.moorewallpaper.com/luftwaffe-13.jpg

Gibbage, the rear spar has 6 holes in it between the wing root and the outer end of the flap.

Bremspropeller
11-23-2009, 05:19 PM
The gap actually looks a bit les dramatic on a servicable aircraft:
http://www.grossostheim-im-krieg.de/assets/images/autogen/a_Heinz_Vontin_in_in_seiner_FW_190-A8.jpg

Maybe other museums are taking a tiny little better care of their exponats:

http://upload.wikimedia.org/wikipedia/commons/d/dc/FW_190_F.jpg

http://img.photobucket.com/albums/v672/Sboot/Fw190ARote1.jpg

http://www.rafiger.de/Homepage/FBMuseum/Info-JG3Udet/Bilder/JG3-Yellow6.jpg

Gibbage1
11-23-2009, 05:22 PM
Originally posted by Bremspropeller:
The gap actually looks a bit les dramatic on a servicable aircraft:


I would like to see more then just 1 or 2 photo's. I also want to see what the flap area looks like when its deployed. Thats nother possible source of ventilation. Again, im at work for a few more hours, so I dont have access to my resources.

Gibbage1
11-23-2009, 05:31 PM
http://aircraftwalkaround.hobbyvista.com/fw190f8/fw190f8_11.jpg

Hummmm. More "holes" in this fuel vapor therie.

The_Stealth_Owl
11-23-2009, 05:39 PM
http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif (http://www.quarry.nildram.co.uk/WW2guneffect.htm)


Click on the smiley face.

Bremspropeller
11-23-2009, 06:21 PM
Well Gib, the spillage out of these holes wouldn't be that great as the flap itself covers them pretty well.


But I think we can - after all we've assembled now - pretty much declare the 30mms a winner, as the fuel-vapor theory would require a fair amount of vapor inside the wing or wingjoin-area to provide a danger over a long-enough time-frame to make the plane vulnerable to the extent seen in the guncam.

In short: lots of vapor needed for the same boom-effect.
Is there any source in the aircraft that can provide that amount of vapor?
Yes there is - but the ammo-explosion would be a lot more likely, given the required circumstances for a vapor-explosion.


Now, the next step would be finding out to what extent different loadouts of 20mm HE were putting up danger to the aircraft.

Would be nice if we could draw a line at the end of the thread and more or less agree on what the odds are of getting a 30mm cook-off and of getting a 20mm coock-off.

Kettenhunde
11-23-2009, 06:33 PM
The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
The in-flight wing fire for undetermined reasons.

http://www.ntsb.gov/ntsb/brief...20040408X00427&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20040408X00427&key=1)


corrosion pitting of the number six cylinder on the left engine, and subsequent fatigue fracture and separation of the cylinder, which led to an engine compartment fire, wing fire, and an in-flight separation of the left wing.

http://www.ntsb.gov/ntsb/brief...20001208X05902&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X05902&key=1)



the failure of a titanium hydraulic line, which resulted in an uncontained hydraulic fluid wing fire.

http://www.ntsb.gov/ntsb/brief...20001207X04356&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001207X04356&key=1)


INFLIGHT ENGINE/WING FIRE DUE TO A FAILURE OF THE RIGHT ENGINE'S LEFT EXHAUST TAILPIPE. THE EXHAUST TAILPIPE FAILED IN FATIGUE AS A RESULT OF FLUCTUATING STRESSES INDUCED BY A DETERIORATED ENGINE MOUNT IN CONJUNCTION WITH UNEVENLY DISTRIBUTED CLAMPING LOADS CAUSED BY AN IMPROPERLY SEATED GASKET.

http://www.ntsb.gov/ntsb/brief...20001213X28486&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X28486&key=1)

And it goes on and on and on and on.....

Guys the wings in airplanes catch fire and burn because of the flammable junk in the bilge.

That is a fact.

These airplanes are not being shot at either....

Gibbage1
11-23-2009, 06:45 PM
Originally posted by Bremspropeller:
Is there any source in the aircraft that can provide that amount of vapor?
Yes there is - but the ammo-explosion would be a lot more likely, given the required circumstances for a vapor-explosion.


For once, I can say without resurvation, I agree 100%.

Gibbage1
11-23-2009, 06:57 PM
Originally posted by Kettenhunde:
http://www.ntsb.gov/ntsb/brief...20040408X00427&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20040408X00427&key=1)


Twin engine aircraft, with fuel stored in the wings. How does this relate to a single engine FW with no fuel in the wings?



http://www.ntsb.gov/ntsb/brief...20001208X05902&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X05902&key=1)


Another twin engine aircraft, with fuel stored in the wing. Again, how does this relate to a FW-190 with no fuel stored in the wing?



http://www.ntsb.gov/ntsb/brief...20001207X04356&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001207X04356&key=1)


Again, yet another twin engine aircraft, with fuel stored in the wings. Are you even trying?



http://www.ntsb.gov/ntsb/brief...20001213X28486&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001213X28486&key=1)


Guess what? Yep. Another twin engine aircraft, with you guessed it! Fuel stored in the wing?

Now, if you can find an NTSB report of a single engine aircraft, that had a wing fire with no fuel in wing, you MIGHT have something. But as it is, your just looking desperate and petty.

Now I remembe why I blocked your post's. No useful information what-so-ever.

deepo_HP
11-23-2009, 07:10 PM
Originally posted by Gibbage1:
But as it is, your just looking desperate and petty.

Now I remembe why I blocked your post's. No useful information what-so-ever. i find your tone petty.

i also find the information given quite good. if it is useful, depends probably on how one wants to use it.
anyways better than manipulated youtube-footage.

Gibbage1
11-23-2009, 07:25 PM
In what way were the reports useful to the topic? Here we have a single engine aircraft with no fuel in the wings, with wing explosions. He post's NTSB about dual engine aircraft with fuel in the wings, were they have fire. Note, none of his reports mention explosions. Some of them landed safe. The rest burned through, but no explosion.

So how is that useful?

deepo_HP
11-23-2009, 07:45 PM
Originally posted by Gibbage1:
Here we have a single engine aircraft with no fuel in the wings...
He post's NTSB about dual engine aircraft with fuel in the wings... as i said, how much it is useful depends on how one wants to use it.

for a start, i can see, that the reports are about 'fuel in the wings', where you (with nothing to back it up for sure) insist on 'no fuel in the wings'.

you probably might want to add, that you meant 'fuel tanks', but that was not the point. the point is, if there is a possibility to have flammable substances in the wings and outside the tanks. you assume(!), that there is none in the 190a, the information in the reports indicate different.

yuuppers
11-23-2009, 07:50 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
The in-flight wing fire for undetermined reasons.

http://www.ntsb.gov/ntsb/brief...20040408X00427&key=1 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20040408X00427&key=1)

Guys the wings in airplanes catch fire and burn because of the flammable junk in the bilge. </div></BLOCKQUOTE>

No kidding but they do have wing engines and fuel tanks. http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

Cessna 414
http://executiveaviationrc.com/images/cessna414_sm_hanger.jpg

Gibbage1
11-23-2009, 08:29 PM
Originally posted by deepo_HP:
as i said, how much it is useful depends on how one wants to use it.

for a start, i can see, that the reports are about 'fuel in the wings', where you (with nothing to back it up for sure) insist on 'no fuel in the wings'.

you probably might want to add, that you meant 'fuel tanks', but that was not the point. the point is, if there is a possibility to have flammable substances in the wings and outside the tanks. you assume(!), that there is none in the 190a, the information in the reports indicate different.

The likleyhood of fuel being in the FW-190 wing is EXTREAMLY low given how well vented it is, and the obsticals in the way. ITs a lot more likley to be the ammo, then some random freak accedent that somehow spilled fuel into a wing section 5 feel away from the source. Thats what im saying.

On the NTSB reports, the fuel is stored in the wing. Meaning its not some feak accedent that fuel is there.

Yes, fires DO exist on aircraft. But I have yet to see one caused 5 feet away from any fuel source.

Kettenhunde
11-23-2009, 09:28 PM
But I have yet to see one caused 5 feet away from any fuel source.


Gibbage that is because you make a bunch of internet assumptions without any experience and think you are doing something good.

Let see, besides the absurdity of youtube...you have invented some silly notion of "venting".

I mean really, what is that??

Leakage drag is pretty well know and understood by designers, but is obviously not understood by you or some of the others who are not in this to prove any point but just to chuck rocks at me.

Gee, it is amazing that a typical WWII radial engine aircraft that is dumping 10-20 quarts of oil per hour, hydraulic fluid, fuel, and other flammables into the fuselage/wing as it operates could possibly have combustible fumes.....

Maybe you can do some graphic artwork on it when you work with airplanes, huh?

Gibbage1
11-23-2009, 10:07 PM
I really really need to question if you work on aircraft at all Ketten.

So your saying that all aircraft always have enough fumes inside the body and wings to just randomly blow up? You do realize that these flying disasters you describe fire guns, dont you? Those guns product lots of sparks. They also produce LOTS of gas, that must be vented out. If there was no way to vent out these gases, then the panels would be blown off. So not only do these gases from the guns need to be vented, but the gases from the engine that being pumped in to warm the ammo.

I also demonstrated over and over and over with diagrams and photo's showing that the FW-190 has plenty of holes to keep good airflow, preventing buildup of possible fumes. In the wheel wells, gun ports, gun covers, ammo chutes, and flaps.

If you cant understand this very very basic concept, I really doubt you work on aircraft at all.

BillSwagger
11-24-2009, 03:12 AM
i agree that there could be combustible fluids in the wings of the 190.

Given that these combustible fluids must leak to get into the wing, whether through gravity or osmosis, you still have a source of that leak that doesn't originate in the wing.

If i let gas leak from a can ten feet away, and light the end thats ten feet away, what happens?

You could argue that the aircraft acts as an enclosure, but i think there is enough air with in the fuselage and wing, where fire would quickly spread to the engine, or fuel bay, where these fluids are leaking from. I'm not familiar with fire science, but something tells me this would happen as a very rapid explosion, or there would simply be more flames and smoke coming from other parts of the plane.

The reason why its not a fuel explosion is we only see a flash in mid wing, a puff of smoke, and in many shots the wing separating.

Maybe someone can explain how this explosion mid wing leads to no other fire or explosion toward the source of the leak.
That process is just not likely to happen, in fact, it might not even be physically possible, but fire science is a subject i'm not very familiar with.

Bill

Kettenhunde
11-24-2009, 04:57 AM
I also demonstrated over and over and over with diagrams and photo's


Gibbage,

You haven't demonstrated a thing.

You show some photos and obviously do not understand simple things like control surface balance and sealing. Your photo is of an aircraft missing the flap. Well the nose of the flap has a lip that is designed to seal the wing shut when the flap is retracted.

I love you proof of lightening holes behind a set of flaps as proof of this "venting" theory.

What is really amusing is the fact others got into the act of posting non-airworthy aircraft missing parts as proof to back it up.....

Classic Ubizoo....

http://forums.ubi.com/images/smilies/25.gif

RegRag1977
11-24-2009, 06:21 AM
Originally posted by Kettenhunde:

you or some of the others who are not in this to prove any point but just to chuck rocks at me.



Well, i don't think they are trying to chuck rock at you for personal reasons, in fact i think some are so angry because you try to explain them, that the wing explosion could be something else than what they hope to prove a "design flaw":

Germany built (most important thing) wing canons HE shells. http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

http://i803.photobucket.com/albums/yy314/RegRag/i-want-to-believe.jpg

At the beginning it was all Fw, then it was all A8, now is it all A8R2 A8R8 or something like that? still without any numbers on how often it did occur: to me it is clearly a question of faith here, not science. Trying to put the FW190 alone without comparing its weak points to other opponent AC weak points appears like an attempt by red fanboys to prove that only the Fw190 had something dangerous that could explode IMHO.

But I feel it is getting better! Had you and other guys not posted in this thread and we would still be at the footage, 50 cal punches wings off 190s easily starting point http://forums.ubi.com/images/smilies/88.gif !

BillSwagger
11-24-2009, 07:36 AM
Originally posted by RegRag1977:


At the beginning it was all Fw, then it was all A8, now is it all A8R2 A8R8 or something like that? still without any numbers on how often it did occur: to me it is clearly a question of faith here, not science. Trying to put the FW190 alone without comparing its weak points to other opponent AC weak points appears like an attempt by red fanboys to prove that only the Fw190 had something dangerous that could explode IMHO.

But I feel it is getting better! Had you and other guys not posted in this thread and we would still be at the footage, 50 cal punches wings off 190s easily starting point http://forums.ubi.com/images/smilies/88.gif !

Actually, on page one of the thread i raised the point that any aircraft carrying similar ammunition may have shared similar risks.
That point didn't get addressed until pages 28 when Gibbage posted the Spitfire armor diagram that shows armor plates specifically covering the ammunition and labeled as such in the diagram.

Part of the reason this thread has carried into two parts is because much of the discussion seems to be defending valid sources, rather than trying to present alternative theories. i refuse to defend my sources, they are valid. Mocking them, nor cracking jokes about "red fanboys" (WTF?? lol, never heard this term before) aka rock throwing, doesn't really facilitate the discussion, does it? You are throwing rocks at armored tanks, if we are to keep that metaphor, until you present valid information that explains what else it could be.

I completely open to that discussion, its just so far the most plausible is ammo detonation.

Bill

Manu-6S
11-24-2009, 08:35 AM
Originally posted by BillSwagger:
You are throwing rocks at armored tanks, if we are to keep that metaphor, until you present valid information that explains what else it could be.

You're lucky that they aren't throwing you 50cals... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

JtD
11-24-2009, 08:44 AM
Originally posted by deepo_HP:
you probably might want to add, that you meant 'fuel tanks', but that was not the point. the point is, if there is a possibility to have flammable substances in the wings and outside the tanks. you assume(!), that there is none in the 190a, the information in the reports indicate different.

..as possible as the white stuff in the bottles on your doorstep which the milkman delivered a minute ago actually being white paint.

100% possible, 0% likely.

Think a scenario short of sabotage to illustrate where the fuel came from, I'd be curious to know.

Kettenhunde
11-24-2009, 09:08 AM
100% possible, 0% likely.


Only problem with your logic, is we are not talking about milk bottles and paint.

You sit behind a computer an form an intellectual concept about these machines and then work very hard to defend it when reality does not fit that mental model.

Don't feel bad, you have lots of company.

http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

RegRag1977
11-24-2009, 09:27 AM
Originally posted by BillSwagger:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RegRag1977:


At the beginning it was all Fw, then it was all A8, now is it all A8R2 A8R8 or something like that? still without any numbers on how often it did occur: to me it is clearly a question of faith here, not science. Trying to put the FW190 alone without comparing its weak points to other opponent AC weak points appears like an attempt by red fanboys to prove that only the Fw190 had something dangerous that could explode IMHO.

But I feel it is getting better! Had you and other guys not posted in this thread and we would still be at the footage, 50 cal punches wings off 190s easily starting point http://forums.ubi.com/images/smilies/88.gif !

Actually, on page one of the thread i raised the point that any aircraft carrying similar ammunition may have shared similar risks.
That point didn't get addressed until pages 28 when Gibbage posted the Spitfire armor diagram that shows armor plates specifically covering the ammunition and labeled as such in the diagram.

Part of the reason this thread has carried into two parts is because much of the discussion seems to be defending valid sources, rather than trying to present alternative theories. i refuse to defend my sources, they are valid. Mocking them, nor cracking jokes about "red fanboys" (WTF?? lol, never heard this term before) aka rock throwing, doesn't really facilitate the discussion, does it? You are throwing rocks at armored tanks, if we are to keep that metaphor, until you present valid information that explains what else it could be.

I completely open to that discussion, its just so far the most plausible is ammo detonation.

Bill </div></BLOCKQUOTE>

Fair enough Bill. All my apologizes for the joke...it wasn't intended to be mean BTW, nor especially aimed at you. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

If you look carefully at the beginning of your thread you'll find that i was one of the first person ready to admit that the smoke puffs could be from a 30mm set off http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif !
All the videos shew very different kind of wing offs (visual) thus my interogation on their possible different origin (propellant ignited as the wing is broken at the moment of a normal wing off, fuel vapor, shell set off, normal wing offs)while for some it had to be ammo canisters everytime http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif . Some footage like the one where the fuel tank exploded was misleading IMHO.
Remeber: all these alternative theories are just to occur as rarely, or as often if you prefer as the ammo set off one, until you show some proofs saying otherwise http://forums.ubi.com/images/smilies/10.gif .

This is at least my opinion, i admit not being a specialist, this is why i keep my ears open: Sometimes staying in an armour is not the best thing if you want to see and understand what is happening outside BTW...

I knew the possibility of a 30mm being set off (but i did not know the possibility was greater with 50 cal ammo) for this has already been discussed a long time ago IIRC on these boards and on CWOS ones, at the time bluefanboys whined about what they called glass FW.
Fact is that apart from the video you posted showing something you interpreted like ammo explosion you did not come with any definitive proofs on the subject. As for Typhoons, Spitfire and Tempest exemples you mentionned you did not even follow your own (Youtube) methodology.

I would never mock you or any valid source or valid opinion, yet since you seem so sure about it i was rather looking for something like valid proofs!

I still think that without proofs this thread is like:

http://i803.photobucket.com/albums/yy314/RegRag/i-want-to-believe.jpg

It's more about faith than sciencehttp://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

edit (BTW no need to use bad language and sorry for the poor english)

RegRag1977
11-24-2009, 09:28 AM
Originally posted by Manu-6S:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BillSwagger:
You are throwing rocks at armored tanks, if we are to keep that metaphor, until you present valid information that explains what else it could be.

You're lucky that they aren't throwing you 50cals... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif </div></BLOCKQUOTE>

LOL http://forums.ubi.com/images/smilies/88.gif

BillSwagger
11-24-2009, 09:28 AM
Originally posted by JtD:
Think a scenario short of sabotage to illustrate where the fuel came from, I'd be curious to know.

Following logic is not necessary to raise valid questions. I just think that when you see video footage that can be interpreted a variety of ways, then you need to look into possibilities.

Find a fuel fire, and watch me try and prove to you it was caused by ammo detonation. You have the same set of probabilities, but there are obvious differences in the results of the two types of explosions.

This is the conflict with the fuel explosion argument.

BillSwagger
11-24-2009, 09:29 AM
Originally posted by Manu-6S:
You're lucky that they aren't throwing you 50cals... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

touche' http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kettenhunde
11-24-2009, 09:49 AM
Let's follow the logic found in this thread to counter the fact aircraft bilges are nasty and full of flammable stuff!

Maybe along the way, some younger folks will see the value of critical thinking and even more importantly, experience.

We can't have fires, the wing is too well ventilated....

Despite the fact engine compartment fires occur frequently and despite being the most "well ventilated" part of the airplane,

We cannot have bilge fires because we don't have fuel tanks or oil tanks located in that portion of the airplane...

Well, the P-40 does not have an oil tank in the wing roots either.

http://img267.imageshack.us/img267/4590/p40belly.jpg (http://img267.imageshack.us/i/p40belly.jpg/)


MMMMMM...Spitfire wheel wells do not have an oil tank.

http://img130.imageshack.us/img130/5702/spitfiremkvbunderside.jpg (http://img130.imageshack.us/i/spitfiremkvbunderside.jpg/)

Now this Spitfire is definitely got a leak in the belly oil tank...oh yeah, it does not have a belly oil tank.

http://img137.imageshack.us/img137/6712/dp845bank.jpg (http://img137.imageshack.us/i/dp845bank.jpg/)

Sorry guys, I couldn't find any picture of non-airworthy display aircraft.

Only airplanes that fly show the milk.....

BillSwagger
11-24-2009, 09:55 AM
Originally posted by BillSwagger:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
Think a scenario short of sabotage to illustrate where the fuel came from, I'd be curious to know.

Following logic is not necessary to raise valid questions. I just think that when you see video footage that can be interpreted a variety of ways, then you need to look into possibilities.

Find a fuel fire, and watch me try and prove to you it was caused by ammo detonation. You have the same set of probabilities, but there are obvious differences in the results of the two types of explosions.

This is the conflict with the fuel explosion argument. </div></BLOCKQUOTE>

horseback
11-24-2009, 10:39 AM
KH, that round, tubular looking thingie on the underside of the Spitfire's left wing is an oil cooler. In the later Marques of the Spitfire, I believe that the oil cooler was combined with radiator/intercooler radiators underwing, so all Spits did have a certain amount of flammables in their wings exclusive of ammo.

Messerschmitts' oil coolers were also notoriously leaky, but because they were located under the nose, that blatant streaking was largely confined to the center of the fuselage. However, the FW 190 didn't seem to be subject to the same degree of photogenic normal leakage, did it? And let's agree that excess lubricants, hydraulic leaks, and the dirt & mud thrown up from landing and taking off from a grass field will all look very similar to each other.

Now, I do understand that mechanical things like piston powered airplanes are subject to a fair amount of shaking & vibration under the most benign of circumstances and that it is close to impossible to obtain air/water tight connections for fuel, hydraulics and lubricants as result. I also accept that there is always going to be a certain amount of 'stuff' sloshing about, and that it will be found in the damndest places as well.

ALL of these will burn like a torch if the right fuel-oxygen mix is achieved and a sufficient source of ignition is provided. Heck, aluminum sheet burns fairly easily if the proper surface area and heat source are present...

Still, I find it hard to believe that you're going to consistantly get that explosive effect in that location in that aircraft very often without the ammo going off-although I would buy the idea that if there was a lower grade bilge fire inside the wing that it might set off the ammo.

If your 'burning bilge' theory is correct, I would expect that we would see a similar sample of 109 wings bursting at the midpoint (with or without gondolas). After all, the 109's fuel is stored in a similar location in the fuselage & one would expect that leakage would extend to that aircraft's midwing too, right?

And before we get into that old chestnut about "they only show the most spectacular gun camera film", I would point out that the vast majority of gun camera film was over-or underexposed and next to impossible to comprehend for the layman.

Even the 'good stuff' we see (again & again) is of pretty poor quality. I would suggest that there is a limited amount of 'clear' gun camera film but that it constitutes a fair sample of all types of gun firing situations. The reason that these films survived was that they were clear enough to be useful for instruction or publicity.

cheers

horseback

M_Gunz
11-24-2009, 11:13 AM
There is a difference between "must be", "could be" and "you must mean". But then some people don't get my sig either.

Gibbage1
11-24-2009, 11:43 AM
The body behind the FW has a great amount of open volume just aft of the cockpit and fuel tanks.

http://www.historicflight.cz/month_event/Fw190N/Focke_Wulf_Fw_190N_022.jpg

IF there was a big enough fuel leak to have a critical buildup of fumes in the wing 5 feet away from the tank, then there will most definitly be enough fumes in the aft section of the aircraft. Yes? Why didnt this area also go up?

Once ignighted, the flames would most certinly follow up to the source. Even if the tank managed to reseal itself, that fire would set off the aft portion. But we dont see that in the films. Because, most likley, there is not enough fuel vapors in the aircraft to ignight.

Also, with the general spread of 6-8 .50 cal armed aircraft, your sure to get a few hits into the body. Wouldent that also set off these phontom fumes?

I still think that fumes gathering in a ventilated wing 5 feet away from any fuel source is infinatly more unlikley then just hitting an HE shell and exploding it.

Gibbage1
11-24-2009, 11:47 AM
I also thought I would share this.

http://www.historicflight.cz/month_event/Fw190N/Focke_Wulf_Fw_190N_041.jpg

Thats the fuel tank compartment.

How to fumes get out of there again? BTW, the two holes at the top lead to the cockpit, not the wings.

RegRag1977
11-24-2009, 11:58 AM
Originally posted by Gibbage1:
The body behind the FW has a great amount of open volume just aft of the cockpit and fuel tanks.

http://www.historicflight.cz/month_event/Fw190N/Focke_Wulf_Fw_190N_022.jpg

IF there was a big enough fuel leak to have a critical buildup of fumes in the wing 5 feet away from the tank, then there will most definitly be enough fumes in the aft section of the aircraft. Yes? Why didnt this area also go up?




Actually i think that it happened! isn't what you are describing happening to the 2 kill in the first video posted?

Gibbage1
11-24-2009, 12:06 PM
I dont think it does. The explosion is still off to the left, not the middle. The blast and fireball does envelop a bit of the body, but I dont see anything emenating from the body itself.

Still, the wing looks a lot more ventilated then the fuel bay, dont you agree?

Bremspropeller
11-24-2009, 12:10 PM
http://www.historicflight.cz/month_event/Fw190N/Focke_Wulf_Fw_190N_041.jpg

This is the aft fuel-tank, BTW.

Gibbage1
11-24-2009, 12:21 PM
Originally posted by Bremspropeller:

This is the aft fuel-tank, BTW.

Ah! Your correct! It is the aft section. I see the fuel tank is mounted in the forward section. Good eyes.

According to Crumpp's drawing, the forward section is similar, with two hopes in the top. Maybe he has a photo of it, but I would think it would be of similar construction with it being rather well buttoned up. Not air tight, but it doesent need to be air tight to restrict fumes.

JtD
11-24-2009, 12:25 PM
Imho, with that fuel tank construction, the leaking fuel would just leak out of the bottom of the plane.

That's why I don't find a plausible scenario where fuel vapours spread into the wings.

BillSwagger
11-24-2009, 12:44 PM
i think that fueling leaking from a projectile is pretty much ruled out at this point.
I think Crumps argument is that fluids or vapors over time can accumulate from gravity and osmosis. Understanding osmosis will make it clearer how and why fumes can get into the wing. It doesn't answer why fire from vapors exploding isn't seen anywhere else but the wing.

I need to see a picture similar to the one that looks through the inside of the tail of the fuselage, but instead looks from the belly (fuel tank) through the center of the wing to the wing tip.


Bill

Gibbage1
11-24-2009, 01:08 PM
Just to drill a few more holes into the vapor therie, it looks like there are 6 hiles in the center of the belly pan, according to crumpp's drawing.

http://img26.imageshack.us/img26/2707/fueltank2.jpg (http://img26.imageshack.us/i/fueltank2.jpg/)

At first, I thought they were bolt holes, but if you look at the seperating bulkhead between the two tanks, there are no holes for bolts.

http://www.historicflight.cz/month_event/Fw190N/Focke_Wulf_Fw_190N_041.jpg

It seems those are drainage/ventilation holes. I cant be 100% sure without a good photo of that plate. Crumpp has access to a FW-190. Maybe he can verify if there are holes in the bottom? Then again, he has been rather reluctant to provide any sort of material that is contrary to his belief's.

yuuppers
11-24-2009, 01:14 PM
Originally posted by Kettenhunde:
Let's follow the logic found in this thread to counter the fact aircraft bilges are nasty and full of flammable stuff!

Maybe along the way, some younger folks will see the value of critical thinking and even more importantly, experience.

We can't have fires, the wing is too well ventilated....

Despite the fact engine compartment fires occur frequently and despite being the most "well ventilated" part of the airplane,

We cannot have bilge fires because we don't have fuel tanks or oil tanks located in that portion of the airplane...

Yes despite oil and fuel being supplied under pressure to the engine compartment with an ignition source readily at hand.

Maybe some will loose their single dimensional thinking.

If we take Crumpp's statement that wing bilges are dirty places filled with all kinds of nasty substances that are a hazard to the welfare of the a/c, then any time an API round hits the wing we should have a catastrophic explosion.

Taking his logic even further, a/c stink of fluids, so any round hitting anyplace on the a/c can cause a catastrophic explosion.

Gibbage1
11-24-2009, 01:24 PM
Originally posted by yuuppers:
If we take Crumpp's statement that wing bilges are dirty places filled with all kinds of nasty substances that are a hazard to the welfare of the a/c, then any time an API round hits the wing we should have a catastrophic explosion.

Taking his logic even further, a/c stink of fluids, so any round hitting anyplace on the a/c can cause a catastrophic explosion.

Not to mention, ANYTIME THEY FIRED THERE OWN GUNS!

Bremspropeller
11-24-2009, 01:24 PM
If we take Crumpp's statement that wing bilges are dirty places filled with all kinds of nasty substances that are a hazard to the welfare of the a/c, then any time an API round hits the wing we should have a catastrophic explosion.


By that logic, gas-stations would have to blow-up everytime someone lights a cigarette.

Gibbage1
11-24-2009, 01:30 PM
Originally posted by Bremspropeller:

By that logic, gas-stations would have to blow-up everytime someone lights a cigarette.

It takes a spacific air/vapor mixture to have the explosive properties. Watch Mythbusters. Gas stations are open air, thus vented. Its just in general a bad idea to smoke with flamable liquids around.

psykopatsak
11-24-2009, 01:34 PM
if the aircraft was draggy enough to somehow allow fuel to some remote part of the aircraft, i cannot for once in my life believe that it would be towards the wing cannons. then i think it would be sucked out at the rear of the aircraft because of the de-pressurised area directly behind an airplane.


also, at the spit images: the spit DOES have something in its wheel wells, because of the HYDRAULIC landing gear, as well as the oil-coolers on the underside of the aircraft.

TS_Sancho
11-24-2009, 01:42 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">100% possible, 0% likely.


Only problem with your logic, is we are not talking about milk bottles and paint.

You sit behind a computer an form an intellectual concept about these machines and then work very hard to defend it when reality does not fit that mental model.

Don't feel bad, you have lots of company.

http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif </div></BLOCKQUOTE>

There is a bit of irony at work here.

After 36 pages it seems clear to me that some of the opinions expressed in this thread are being made by people with no more practical mechanical experience than signing a work order at the quickie lube.

A couple of folks here need to spend some time getting their hands dirty. Spend a couple of weeks scraping goo off parts while bathed in MEK, I'm willing to bet the experience might change a couple of minds . Theory is important but without practical experience it doesn't count for much in the real world.

JtD
11-24-2009, 01:52 PM
I've been to some very dirty places, seen a lot of dirty old parts. I'm sure I could have made them burn, but none of them explode.

BillSwagger
11-24-2009, 02:00 PM
Originally posted by TS_Sancho:

After 36 pages it seems clear to me that some of the opinions expressed in this thread are being made by people with no more practical mechanical experience than signing a work order at the quickie lube.


Which is why I've learned to sit back and ask the questions, because i find that most of what is expressed as opinion has factual basis, but not easily explained by the video footage.
I can talk about how hamsters broke into the wing of the 190 and chewed up a chord that could've caused a spark in the wing which caused fumes to explode. I used to own a hamster, i know from practical hands on experience what they are capable of.

So there's my hands on experience take on it. Does that make it more likely than the theories provided here. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Its not really a matter of being right or wrong, its just ruling out possibilities, thats all.



Bill

TS_Sancho
11-24-2009, 02:13 PM
I can talk about how hamsters broke into the wing of the 190 and chewed up a chord that could've caused a spark in the wing which caused fumes to explode. I used to own a hamster, i know from practical hands on experience what they are capable of.

Good point on the gerbils. Does anyone have any hard data on european hamster populations in '43/44?

After a quick wiki search it would seem the germans were well aware of the problem as they seem to be responsible for naming the buggers.


The name hamster is derived from the German verb hamstern, which means "to hoard" because hamsters have expandable cheek pouches lined with fur to store their food.[1] The word hamstern itself comes from earlier Old High German hamustro .

http://en.wikipedia.org/wiki/Hamster

I think in light of this new evidence its obvious we have all been looking in the wrong direction.

TheGrunch
11-24-2009, 02:19 PM
There is another compelling possibility (http://www.youtube.com/watch?v=CUYZYJ7XueI).

TS_Sancho
11-24-2009, 02:31 PM
Originally posted by TheGrunch:
There is another compelling possibility (http://www.youtube.com/watch?v=CUYZYJ7XueI).

http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/88.gif http://forums.ubi.com/images/smilies/88.gif

Excellent post http://forums.ubi.com/images/smilies/11.gif

RegRag1977
11-24-2009, 02:34 PM
Originally posted by TheGrunch:
There is another compelling possibility (http://www.youtube.com/watch?v=CUYZYJ7XueI).

http://forums.ubi.com/images/smilies/sleepzzz.gif Run, rabbit run
dig that hole
Forget the sun
And when at last the work is done
Don't sit back it's time to dig another one?

edit Oh no it's a hare, not a rabbit http://forums.ubi.com/images/smilies/25.gif

Gibbage1
11-24-2009, 02:37 PM
Nice. I post about possible holes drilled into the belly pan for venting and draining, and everyone ignores that.

TS_Sancho
11-24-2009, 02:51 PM
Originally posted by Gibbage1:
Nice. I post about possible holes drilled into the belly pan for venting and draining, and everyone ignores that.

I agree Gibbage, the Hamsters have to be getting in from somewhere.

Sorry, couldnt resist. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

RegRag1977
11-24-2009, 03:38 PM
Originally posted by Gibbage1:
Nice. I post about possible holes drilled into the belly pan for venting and draining, and everyone ignores that.


Sorry Gibbage,

I'm not sure what holes you are talking about, but those i see on the belly pan seem very small to me.
Plus i don't know how many place the bladder would take once filled with fuel, and with that i don't know if it would be enough to drain knowing that the synthetic fuel used was oily and thicker than normal fuel according to Kettenhunde:

quote:

"I don't know. We have it sealed up and I have never even seen the jar.

I was told it smells like tar and has a very oily consistency. It is closer to a light oil than what we think of as gasoline."

Gibbage1
11-24-2009, 03:42 PM
Just trying to keep it on topic, and I think I may have found something to help settle this fume debate. Unfortunately I am at work and I dont have access to anything more then a Google search. I was hoping someone would find a good photo of the belly pan to see if it did have drain holes in it.

If it did, then its a lot less likely to have fume buildup, and even less likely that it would spread to the wings. Air moving over a hole creates a vacuumed, thus sucking any vapor out the holes.

I think the holes are too small for Hamsters.... But there are plenty of holes in the wings even a chubby guinea pig can fit into.

RegRag1977
11-24-2009, 03:44 PM
The holes could be there to attach the keel like centre-line ETC 501 bombrack?

Gibbage1
11-24-2009, 03:49 PM
Originally posted by RegRag1977:
The holes could be there to attach the keel like centre-line ETC 501 bombrack?

Dunno. It depends on how heavy that is, and how wide. 6 holes drilled into aluminum WONT support much weight without some sort of internal brace. There is none I can see.

M_Gunz
11-24-2009, 03:49 PM
Bomb rack would attach to frame, not hang from skin-thin sheet aluminum.

Gibbage1
11-24-2009, 03:52 PM
I dont think he's talking about the bomb rack itself, but a long thin peace behind the bomb rack for what I think is stream lining? Its not my area, so we need to verify this. Ketten? Maybe he's busy taking photo's for us or something.

Gibbage1
11-24-2009, 03:54 PM
http://www.ipmsstockholm.org/magazine/2004/10/images/detail_fw190a8_24.jpg

It LOOKS like something does indeed go into those 6 holes, but note there are two big holes off too the sides. Plenty big for a hamster.

RegRag1977
11-24-2009, 04:05 PM
Originally posted by M_Gunz:
Bomb rack would attach to frame, not hang from skin-thin sheet aluminum.[/QUOTE]

Of course, you're right



I dont think he's talking about the bomb rack itself, but a long thin peace behind the bomb rack for what I think is stream lining? Its not my area, so we need to verify this. Ketten? Maybe he's busy taking photo's for us or something.



That's what i meant, Thanks Gibbage.
All the bombrack weight is not on the aluminium sheet (but on the frame, thank God! http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif ), but for some reasons the rear part of it seems to be attached to it. Maybe for aerodynamics purpose...

Gibbage1
11-24-2009, 04:28 PM
My best guess is to stabilize its horizontal and latteral movement, not vertical movement. For that, I think the aluminum sheet would do, since its not supporting weight, but stopping side to side movement.

I still want to see the full plate, and aft, to see if there is drain holes. Many modern aircraft do have drain holes under the fuel tanks and engine bays. They typically have a metal straw sticking down about 1", thats cut aft to promote vacuume. Im not sure about WWII aircraft. If I still lived in LA I would just ride over to Chino and check them out.

yuuppers
11-24-2009, 06:38 PM
Gibbage, the small hole in the underside of the fuel tank compartment is for the fuel pump. The bigger hole is for the fuel level sensing unit. There is no opening to the cockpit when these pieces are installed.

TheGrunch
11-24-2009, 06:38 PM
Originally posted by RegRag1977:
Oh no it's a hare, not a rabbit http://forums.ubi.com/images/smilies/25.gif
I'll let you off for the Floyd lyrics. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif Which leads me to a thread I meant to start a while ago...

BillSwagger
11-24-2009, 07:15 PM
After 36 pages it seems clear to me that some of the opinions expressed ...........

Yeah, i also have to mention the compelling argument thats been made about how easily the 190 explodes from fuel build up in the binge.

It just seems as though the plane should explode more easily, shouldn't it.

So i guess whether from ammo detonation or fuel explosion, i can see how the wing comes off either way, easily, and quite catastrophically.



I can't wait now, to hear how nonexplosive and fire resistant the plane is.

Hopefully its obvious i'm being facetious, i just get a kick out of how some of these arguements tend to pan out after a while.
When in the end, we can still say what the title says no matter which argument you agree with, correct?

http://forums.ubi.com/images/smilies/disagree.gif


http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Gibbage1
11-24-2009, 07:26 PM
Originally posted by yuuppers:
Gibbage, the small hole in the underside of the fuel tank compartment is for the fuel pump. The bigger hole is for the fuel level sensing unit. There is no opening to the cockpit when these pieces are installed.

Thanks for clerification. Do you know of any other holes that can be used for drainadge in the belly pan?

Also, looking at the photo's, it looks like there is a gap between the belly pan, and ammo bay thats forward of the fuel tanks. Its too hard to tell to make any real judgement without better photo's.

deepo_HP
11-24-2009, 07:34 PM
Originally posted by BillSwagger:
When in the end, we can still say what the title says no matter which argument you agree with, correct? imo, exactly the title is the most incorrect statement in the whole discussion.

'footage': no, just youtube videos
'50 cal': maybe, possibly other calibres
'punches wings off': no for 50 cal (it is the only so far agreement, that the punch is caused by something else than kinetics of bullets), yes for he-ammo (like 20mm hispano).
'easily': no for 'frequently', no for '50 cal', no for a general statement on the 190's wings - no in all regards.
'fw190s': the only point of discussion, still only hypothetical arguments.

it seems to me, that you don't get your facetious kicks on panned out arguments, but simply by repeating your initial incorrect statement once in a while.

BillSwagger
11-24-2009, 11:43 PM
Originally posted by deepo_HP:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BillSwagger:
When in the end, we can still say what the title says no matter which argument you agree with, correct? imo, exactly the title is the most incorrect statement in the whole discussion.

'footage': no, just youtube videos
'50 cal': maybe, possibly other calibres
'punches wings off': no for 50 cal (it is the only so far agreement, that the punch is caused by something else than kinetics of bullets), yes for he-ammo (like 20mm hispano).
'easily': no for 'frequently', no for '50 cal', no for a general statement on the 190's wings - no in all regards.
'fw190s': the only point of discussion, still only hypothetical arguments.

it seems to me, that you don't get your facetious kicks on panned out arguments, but simply by repeating your initial incorrect statement once in a while. </div></BLOCKQUOTE>

I just don't see how you can disagree with everything and not back it up with more information.
each one of your points has been addressed, and backed with more info.
You tube video is footage, if it were Vimeo would it be any less reliable, or how about the actual archive that its an exact copy of.
What standard of proof are you expecting me to show?
I could make it easier to agree, and say "USAAF planes punches wings..." I'm not trying to insult you Deepo, i actually respect your opinions. You've contributed a lot already, which has offered more information on the ammo fusing.

The P-38 is the only cannon plane, so that might be a place to see if it is in fact a cannon shell. There were also 20mm AP rounds, not every 20mm shell was HE. So it is an unfair assumption that it is 100% 50 cal.
Maybe you could show me something that helps elaborate why it may be another caliber, so far everything i've found points to 50 cal with the remote chance that there could be some P-38 footage in there. Given the trajectory of the tracers, it appears to be coming from two wings which as we all the 38s had guns in the nose.


hypothetical arguments.
I'm not sure what is hypothetical, i'm looking at the footage and seeing the wings being blown off a 190, and in several reels.
Also, gas does burn, and apparently the plane bathes in it before take off.
And based on the diagrams you provided, the fusing indicates the shells detonate from impact. Thats what they were designed to do.



Bill

Gibbage1
11-25-2009, 12:12 AM
P-38 guncam footage is easy to spot. The guncam was located in the nose, directly under the 20MM and 4 .50 cal. When fired, everything would blur quite a bit. The later P-38L put the camera in the bomb mount of the left wing between the engine and gondola. You can see the prop blur, and sometimes the gondola itself depending on the FOV set on the camera. These are not P-38 guncams.

yuuppers
11-25-2009, 01:01 AM
Originally posted by Gibbage1:
Thanks for clerification. Do you know of any other holes that can be used for drainadge in the belly pan?

Also, looking at the photo's, it looks like there is a gap between the belly pan, and ammo bay thats forward of the fuel tanks. Its too hard to tell to make any real judgement without better photo's.

Not that I know of but there would be seepage from the panel edges unless some sealant was used.

The gap would be the clearance for the ammo containers.

Btw, on the MK108 armour. The feed chute folded back over the ammo container.

Some high quality drawings of the 190, http://www.albentley-drawings.com/fw190a_f_g.htm

deepo_HP
11-25-2009, 02:13 AM
hi billswagger,

i am not trying to insult anyone either, nor have i done, imo.

my last reply was directed to your statement, that 'we can still say what the title says no matter which argument you agree with'.
and i just can't say that.

sorry, if the dissecting of what the title says was a bit short, but what i can agree with its, that most points have been mentioned somewhere in the 30+ pages of the thread.


Originally posted by BillSwagger:
I just don't see how you can disagree with everything and not back it up with more information.
each one of your points has been addressed, and backed with more info. exactly that is why i haven't backed up my points: each one has been adressed, and backed up with more info already.
it is ok for me, if everyone draws his own conclusions of agreement and disagreement, but it is not ok to sum it up as 'we can still say what the title says no matter which argument you agree with'.
exactly that is not the case.

furthermore, if someone makes a factual statement like the thread's title, it is not the task for those who doubt it to back it up with 'more' information. it is sufficient to show, that it is not 'enough' information to make such a statement.


Originally posted by BillSwagger:
You tube video is footage, if it were Vimeo would it be any less reliable, or how about the actual archive that its an exact copy of.
What standard of proof are you expecting me to show? the point here is the term 'proof'. there is no 'proof' in that footage. there is indication - nothing more. it would be only indication in the original guncams. youtube or similar is a pretty bad copy of the originals, not giving clues on manipulation or source. as such they are the least desirable footage ever. this has been discussed very much already.
proof is out of question anyway.

in the same way, i questioned the '50 cal' in the title. by far not everything you found 'points to 50 cal' or P-38 or even for 'USAAF'. maybe, maybe not... and has been discussed. and wouldn't be more than a pointer, as you said.


Originally posted by BillSwagger:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">hypothetical arguments.
I'm not sure what is hypothetical, i'm looking at the footage and seeing the wings being blown off a 190, and in several reels. </div></BLOCKQUOTE>again, what you see is a distorted copy of an original bad quality guncam. it shows wings (probably) blown off.
everything else is your own conclusion, or 'hypothesis'. it is hypothetical.

the point here is, that 'hypothetical' doesn't mean 'not possible' or even 'not probable'. however, it doesn't implicate facts. it doesn't mean, that you are wrong, but also it doesn't mean, that it is obvious you are right.
therefor, 'we' can not 'still say what the title says'. that's all.




Originally posted by BillSwagger:
And based on the diagrams you provided, the fusing indicates the shells detonate from impact. Thats what they were designed to do. just for this one detail... (which has been mentioned also, sorry for the repitition)
the fuzes are not(!) supposed to detonate from impact, and the diagrams don't show that. the very meaning of a fuze is to make sure the charge detonates on impact and to allow the most possible safety for all other circumstances. therefor the fuze is quite complicated. it is made of 3 parts, the needle ignites a reactive charge, which then starts the amplifying part, which pulls off the (inert and high-explosive) detonator, which (sometimes over seperate tubes) makes the main charge go off. there are several mechanisms, some of them prevent the needle to start ignition, some prevent the igniting charge to reach the amplifyer... by means of acceleration and/or spin. simply hitting the charge won't do anything, as well as hitting the detonator shouldn't do anything - all within the intention of design and of course it can happen.
for a start, i doubt, that the force per area(!) provided by the needle on impact on target, which is needed to just start the ignition, will be reached by the impact of a bullet. detonator and charge are, imo, safe from that kind of shock.

the general considerations on fuses in this regard date back to world war I (here for artillery grenades):

from: Douglas T. Hamilton (1916). High-Explosive Shell Manufacture. The Industrial Press, N.Y.
[p.39, Charge:]
Trinitrotoluol, when pure, has no odor and is a yellowish crystalline powder which darkens slightly with age. It cannot be exploded by flame or strong percussion and a rifle bullet may be fired through it without any effect.
[p.21, Fuze:]
In order that the body of this detonator will be capable of resisting considerable shock, it is generally made from alloy steel with a tensile strength of about 110,000 pounds per square inch.

from: wikipedia. Tensile Strength.
As [tensile strength] is an intensive property, its value does not depend on the size of the test specimen. It is, however, dependent on the preparation of the specimen and the temperature of the test environment and material.

i won't exclude that it can happen that a bullet hit has consequences... but it shouldn't. which is opposite to you, who considers youtube videos enough evidence, that it happened for sure and easily.


i apologise for my complicated and boring wording. and it might read a bit snobby or so. but it is honestly just so as i hope to find the proper expressions to state what i want to.

M_Gunz
11-25-2009, 02:38 AM
You might also read up on both sheer and compressive strengths. Tensile strength resists stretching therefore bending.

It's not the TNT/RDX that I'd look to see explode first, it's the percussion cap at the end of the fuse. Look up
mercury fulminate some time. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif It's so touchy you don't want to much more than stare hard at it. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

deepo_HP
11-25-2009, 03:13 AM
hi m_gunz,

i am not quite sure what you are relating to.
however, even the ignition charge was not anything to handle carefully. it needed a definite high pressure per area as given by the needle.
the 1916 link just shows how far back-dated the development of fuzes is. the tensile strength advice shows the dimensions necessary to eliminate kinetics from shock treating.
detonators and main charges of minengeschoss were both made of inert explosives and compartimented from ignition and amplifier.

anyways, this was just to reply to billswagger and only to add to one detail he mentioned and with the only purpose to comment on his one note, which i related to.
in the context of my before reply it doesn't matter much.
in that context, i won't say and never had said that charges can't ignite on circumstances. for the rest of the context, pls read my before posts.
i certainly find any addition to the sub-topic of charge detonation very interesting and welcomed, i just want to point out, that it is different from my opinion, that 'we can' not 'still say what the title says no matter which argument you agree with'.


sorry again for my phrasing, but i really don't want to revolve my own unimportant contributions. my only interest in the last replies was to comment, that it can't be concluded on an agreement on the topic's title. it is not anyone's task to bring up evidence against the title's implications, it is in opposite the one who makes a statement to bring evidence.
therefor an agreement on the statement can't be suggested by the one who makes the statement!

(gee, this is probably my masterpiece of kauderwelsch http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif)

M_Gunz
11-25-2009, 05:51 AM
Mercury fulminate is very sensitive stuff, be sure, even stabilized. It doesn't take that much of a whack, a cap gun
can do it through paper for example. You can set it off by pinching it with pliers. There are and have been many
people who didn't think so often with nicknames like Lefty.

As for compressive and shear strength, that is the crushing and cutting strengths per cross sectional area and they
tend to be in the 10's of 1000's of lbs too for steel yet work out the square areas involved in fuse parts and the
total number isn't going to stop a 50 cal bullet at velocity and angle able to pierce 10mm of solid rolled homogenous
armor plate and probably less. That's why they use 50 cal (and maybe 7.62mm) to set off unexploded ordnance for
example, because it works.

orville07
11-25-2009, 06:39 AM
Originally posted by deepo_HP:
hi m_gunz,

i am not quite sure what you are relating to.
however, even the ignition charge was not anything to handle carefully. it needed a definite high pressure per area as given by the needle.
the 1916 link just shows how far back-dated the development of fuzes is. the tensile strength advice shows the dimensions necessary to eliminate kinetics from shock treating.
detonators and main charges of minengeschoss were both made of inert explosives and compartimented from ignition and amplifier.

anyways, this was just to reply to billswagger and only to add to one detail he mentioned and with the only purpose to comment on his one note, which i related to.
in the context of my before reply it doesn't matter much.
in that context, i won't say and never had said that charges can't ignite on circumstances. for the rest of the context, pls read my before posts.
i certainly find any addition to the sub-topic of charge detonation very interesting and welcomed, i just want to point out, that it is different from my opinion, that 'we can' not 'still say what the title says no matter which argument you agree with'.


sorry again for my phrasing, but i really don't want to revolve my own unimportant contributions. my only interest in the last replies was to comment, that it can't be concluded on an agreement on the topic's title. it is not anyone's task to bring up evidence against the title's implications, it is in opposite the one who makes a statement to bring evidence.
therefor an agreement on the statement can't be suggested by the one who makes the statement!

(gee, this is probably my masterpiece of kauderwelsch http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif)

Hallo deepo. Mate, your Kauderwelsch is perfectly comprehensible, and your written English is superb mein freund http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif.

But I'll paraphrase you anyway. An erroneous premise has been made that ".50 cal's punch off Focke Wulf wings easily", a premise unqualified by any incontrovertible, empirical proof. The "burden of proof" is on the OP to qualify his original assertion and premise, (IE proving that they are indeed .50cals in the vid) which he has failed to do beyond reasonable doubt.

I "know" that it is 20mm Hispano blowing that wing off. Not to say that there is not Focke Wulf ammo going off too, which may or may not be the case.

This I cannot prove beyond reasonable doubt. Ergo my (tongue in cheek) assertion that I "know" it is Hispano 20mm is fundamentally flawed too. Touche.

In summary, though well intentioned few here really know what they are talking about, the whole shebang though interesting and entertaining has "proven" nothing.....and was probably an epic waste of time. Extrapolation and conjecture is quite distinct from "fact", but lets be honest, its fun and I too am guilty as charged. http://forums.ubi.com/images/smilies/88.gif

Gentlemen, Thanking you, Thanking you http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/partyhat.gif

BaronUnderpants
11-25-2009, 07:40 AM
The reason the threadh is so long is because everyone KNOWS http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif its NOT .50 cal punching the wings of a Fw190.


What ever it is, be it fuelfumes, 20mm or ammo going of from secondary explosions...we know its NOT .50 cal doing the job. (blowing the wing of)

It may have contributed to the event, but not even that is proven beyond a resonable doubt.


Exclusivly focusing on Fw190 imo we just limit the possibility of finding out what could have cause the dewinging. IF cannon ammo regularly was set of, im sure there should be reports from all the airforces saying so but so far nothing has been shown to sugest that?

Would be nice the know WHY they armoured the ammoboxes/ammo feeds to.(Not only Fw190)

As far as i can remeber we had nothing sugesting secondary explosions from ammo beeing hit, was somehow a major problem or something that happend on a regular basis (if we can, without problem find 4-5 youtubes showin this, as claimed, there sould be a boatload we havent seen yet), we do however have an account of a pilot saying that jamming was somewhat common due to defensive fire from bombers.Imo they armoured the front, top, bottom of cannons/ammo boxes/ammofeeds to prevent just that.


P.S. What exactly can cause white smoke when exploding?

BTW, As stupid as i am, if a cannon round detonates from beeing hit by a bullit, wouldnt that mean it would also detonate as soon as u pulled the trigger? (we are talking about impact forces aint we?)


The more i think about it the more unlikely it sounds to me, a freak "accident", a "one in a milion shot" at best, unlike 4-5 youtubes found without even trying kind of thing.


Or maby not, i dunno http://forums.ubi.com/images/smilies/53.gif

BillSwagger
11-25-2009, 10:16 AM
impact forces

Your right, maybe its not intended to detonate from impact, but rather compression. When fired out of a cannon, everything around the detonator moves at the same speed, so nothing squeezes it. Acceleration alone, would not compress the material to detonate.

It also explains why there is less tendency to have the neighboring rounds detonate from an exploding shell in the ammo box.
The blast would need to be capable of sending shrapnel or possibly blast the shell itself into an obstruction, that would then impact the shell and possibly crush (compress) the detonator.
Secondary explosions are diminished by this, however through low-order ammo detonation there could be cook off of the casings that are damaged or heated from the blast.

Also the diagrams of the armor plates cover the ammo boxes, specifically at the war heads. This was found to be evident of spitfire armor also.

A few other planes carrying cannon shells would need to be looked at to see if they also carry armored plating for the cannon ammo.
It might be easier to see a trend that way, but the armor on the spitfire does show this may not have been an exclusive problem of the 190.


Both the Tempest mk V, and F4U-1c had the same cannons, but i don't have access at the moment to see if they also have armor.


*******

Aside from that,
With some of the other information provided about flammable fuels in the bilge, i wonder if also there was not a greater tendency for gas explosion.
Again, not an exclusive trait of the Fw-190, but it does show how such a plane was actually just as prone to fires as other single engine fighters of that era.
I don't think anyone ever said the plane was fire resistant, only that it had self sealing tanks, but apparently this doesn't exclude the likelihood of other fumes, or fluids through out the fuselage and wings.



Bill

Gibbage1
11-25-2009, 11:13 AM
The P-38 did have some significant armor beween the pilot and the cannon rounds, but realize, that the US and British didnt use a great concentration of HE rounds in there guns. Plus, the walls of the shells were thicker, and had less explosive material.

A hit in the ammo bay is possible, yes. A hit on the warhead is less likley. Then, if the belting is 33/50% HE, then a hit on a HE warhead is even less likley.

Then you have the German loadout of almost 80% MG thin walled shells for 20MM, and 100% MG thin walled shells for the Mk-108. Your more likley to nail an HE round.

Please note, im not saying that ANY hit will cause detination. Nobody can prove that. Im just saying that your chances of HITTING an HE round are greater due to the belting, and I can only guess the thin walled MG shell will be more prone to detonation and simpithetic detinations due to its thin walls, and close proximity to other HE rounds.

DrHerb
11-25-2009, 11:18 AM
I think this is the most accurate footage of .50 cals and guncams on youtube.

Part 1 (http://www.youtube.com/watch?v=1jFFm2m0wfY&feature=related)

Part 2 (http://www.youtube.com/watch?v=FceMrzn7A1M)

Gibbage1
11-25-2009, 12:43 PM
First link didnt have any guncam footage. Just normal BW footage from WWII.

2nd link, still going through it but wow! At .54 THATS a fuel vapor explosions. Look at the chunk of panel it peeled off! The pilot needs a new change of undies trying to dodge that debris! Can anyone ID the target? Looks like a twin engine bomber of some sort, with the outer wings removed?

BTW, the damages and flashes look a lot like 20MM. IF that is .50 cal being fired, im rather suprised.

DrHerb
11-25-2009, 12:51 PM
The title says DO-217's but its hard to tell. But I agree, that looks more like a fuel explosion due to the fireball.

DrHerb
11-25-2009, 01:36 PM
Upon re-watching the original video a few times, Im pretty well convinced that its the wing ammo going off and blowing off the section. The wings separate pretty much at identical locations in the structure and almost in the exact way each time. I really dont think fuel vapour explosions are that aggressive in nature. Looks more like high explosives going off.

But thats just my opinion on the matter but opinions arent facts.

psykopatsak
11-25-2009, 03:33 PM
and what about a tracer plowing through the ammo box?

Gibbage1
11-25-2009, 04:26 PM
Originally posted by psykopatsak:
and what about a tracer plowing through the ammo box?

Im very sure that ANYTHING plowing through an ammo box filled with HE rounds would be bad.

yuuppers
11-25-2009, 04:52 PM
Fw190 with wing tip blown off from a fuel vapour explosion when pilot turned on the nav lights.

http://www.ww2aircraft.net/forum/attachments/aircraft-pictures/105744d1253044340-battle-damaged-aircraft-ww2-126116.jpg

virgule88
11-25-2009, 05:03 PM
Originally posted by yuuppers:
Fw190 with wing tip blown off from a fuel vapour explosion when pilot turned on the nav lights.

<snip>

You need to be registered on that forum to view the image. Please host somewhere else. Thanks you http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Edit: nevermind. I did it myself: http://imgur.com/Npxd9.jpg

TS_Sancho
11-25-2009, 05:07 PM
Originally posted by yuuppers:
Fw190 with wing tip blown off from a fuel vapour explosion when pilot turned on the nav lights.

http://www.ww2aircraft.net/forum/attachments/aircraft-pictures/105744d1253044340-battle-damaged-aircraft-ww2-126116.jpg

The image didnt post, heres the URL

http://www.ww2aircraft.net/for...craft-ww2-126116.jpg (http://www.ww2aircraft.net/forum/attachments/aircraft-pictures/105744d1253044340-battle-damaged-aircraft-ww2-126116.jpg)

If the description is accurate it certainley takes the wind out of the vented wing argument.

Told ya so... http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

Edit...hmmm, the image posted now no problem

Gibbage1
11-25-2009, 05:19 PM
If its accurate? Thats a big if. Is it a pilots assumption? What did the NTSB say (I know it didnt exist)? Any sources? What was the circumstances? Sabotage? Also the construction of the wing tip can be a factor. Bird strike? Maybe he hit a tree while buzzing his friends house, and made up an excuse. I know a lot of this sounds outlandish, but so does a wing exploding a good 10 feet away from any fuel source.

There are only a few things we know for fact, and one of them was that the wing was vented as shown by the holes in many photographs and the induction of air from the exhaust to keep the ammo warm.

Gibbage1
11-25-2009, 05:35 PM
Actually, the damage pattern looks more like a mid air collision, then an internal explosion.

Here is what an internal explosion looks like.

http://www.gibbageart.com/files/dm/Picture20.jpg

Note the large peaces, and lack of shrapnal damage. This is very likley an internal vapor explosion like what was described. Notice the nav lights.

Here is a mid air collision.

http://www.gibbageart.com/files/dm/Picture37.jpg

Notice the straight line, and jagged edges. Very similar to the FW pic.

JtD
11-25-2009, 10:47 PM
Originally posted by TS_Sancho:

If the description is accurate it certainley takes the wind out of the vented wing argument.

Told ya so... http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

The description is neither accurate nor serious. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kettenhunde
11-26-2009, 08:09 AM
Interesting that lights are sealed units on airplanes....

http://www.aircraftspruce.com/.../positionlights.html (http://www.aircraftspruce.com/menus/el/positionlights.html)

Maybe we can make a graphic artwork depiction and see where it fits on the wingtip?

TS_Sancho
11-26-2009, 10:36 AM
Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TS_Sancho:

If the description is accurate it certainley takes the wind out of the vented wing argument.

Told ya so... http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif

The description is neither accurate nor serious. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif </div></BLOCKQUOTE>

So what was the point of posting the photo?

JtD
11-26-2009, 12:47 PM
That's something you'd have to ask the original poster.

I can only say these are interesting pictures, as battle damage pictures usually are and that I got a laugh out of the comment.

Gibbage1
11-26-2009, 01:59 PM
Originally posted by Kettenhunde:
Link to modern day nav lights


http://www.gibbageart.com/files/give_a_damn_progress.gif

yuuppers
11-26-2009, 02:11 PM
Originally posted by TS_Sancho:
So what was the point of posting the photo?

To read the comments. It is rather obvious that it is the result of some sort of collision.

A fuel vapour explosion is very illogical, as if this is actually what happened then every time an a/c was hit with a projectile there would be an explosion. Take a look at photos of P-51s with wing damage (remember the P-51 carried fuel in its wings) and there should have been all kinds of fuel vapour.

As for Crumpp's examples, well they were fuel fires, which is understandable since fuel was there to be ignited. I didn't see one example of a fire far from a fuel source.

Something to think about. Galland smoked cigars in his 109 cockpit and used a lighter he had installed to light it. There was a fuel line in the 109's cockpit.

psykopatsak
11-26-2009, 03:23 PM
from http://www.wwiiaircraftperform...est/tempestafdu.html (http://www.wwiiaircraftperformance.org/tempest/tempestafdu.html)

"All fuel tanks are self-sealing. Bullit-proof windscreen is of "Dry-cell" type. Front side of outer gun ammunition tanks have a piece of 1/8" armour plate. "

just to add to the armoured ammo-boxes.

Gibbage1
11-26-2009, 05:24 PM
Good find! Looks like there is yet more proof that 20MM ammo hits WAS a concern.

But it seems the people who didnt think so have left.

Kettenhunde
11-26-2009, 06:11 PM
High over the Atlantic, a warning light illuminates on the cockpit center console, indicating a possible fire in the aft belly hold.

http://findarticles.com/p/arti...06/?tag=content;col1 (http://findarticles.com/p/articles/mi_m0UBT/is_47_12/ai_53262106/?tag=content;col1)


Fires can start at many locations in an aircraft: - in the turbine
underneath the aircraft due to kerosene spillage
in the undercarriage
in the cargo hold
in the tight cabin (e.g. luggage compartments, in the rows of seats or in the on-board kitchen)
Every fire requires an individual procedure. Training in Drger aircraft fire simulators is the ideal preparation for this.

http://www.draeger.com/US/en_U..._fire_simulation.jsp (http://www.draeger.com/US/en_US/products/training_workshop/fire/dss_aircraft_fire_simulation.jsp)

Heat sensing is used for cargo holds, engines/APUs, toilet waste bins, high temperature bleed air leaks and landing gear bays.

http://www.skybrary.aero/index...re_Detection_Systems (http://www.skybrary.aero/index.php/Aircraft_Fire_Detection_Systems)

Fires occur in engines, engine bays, cabins, cargo holds, wheel wells and fuel tanks.

http://www.scsi-inc.com/FEI.html


A fire needs only three ingredients fuel, air, and an ignition source (heat). Put these three ingredients in the proper juxtaposition, and voila fire. Unfortunately, a running aircraft has plenty of hot things that can quickly ignite a fire.

Electrical power from alternators, generators, and batteries constitutes another potential heat source. With power routed to virtually every part of the aircraft for lighting, deicing, radios, landing gear and flap motors, and fuel pumps, the electrical system is another prime candidate for starting fires. Insulation, adhesives, and fabrics make great fuel for fire, as does the insulation on the wiring itself. Leaking avgas from a primer or fuel-flow gauge, or dripping fluid from a brake cylinder are also excellent fuels that an errant electrical spark can ignite.

http://flighttraining.aopa.org...rep/skills/fire.html (http://flighttraining.aopa.org/students/flighttestprep/skills/fire.html)

yuuppers
11-26-2009, 07:38 PM
Geez Crumpp, no one is saying a/c can't have fires. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif You were the one that brought up a fuel vapour explosion in the outer wing of the 190. Try to stay on the subject of fuel vapour.

Now what heat sensing units were in WW2 fighter a/c?

Btw, do you purge the wing of your plane before every flight since there might be fuel vapour trapped in the wing? How do you purge any fuel vapour that has found it way into the wing when in flight in your plane?

Gibbage1
11-26-2009, 07:59 PM
Crumpp.

You have yet to show a <span class="ev_code_RED">FUEL VAPOR EXPLOSION</span> that was 5 feet away from any fuel, let alone in a well ventilated area.

"Fires occur in engines, engine bays, cabins, cargo holds, wheel wells and fuel tanks."

NO DUH! Try sharing new info with us for once. We have no doubt that fires happen on aircraft. Thats not the topic. Stick to the topic, or please leave. The topic is wing explosions, not cargo hold fires.

JtD
11-27-2009, 12:19 AM
Would an explosion without shrapnel, for instance a fuel vapour explosion, be enough to destroy a wing spar?

I've been thinking about that, and consider it unlikely. For the simple reason that the pressure will go the way of the least resistance, through the thin aluminum sheets, and not through the most solid object in the area.

If the wing was a simple void object with a spar inside, meaning no ribs and rivets between ribs and wing surface, the explosion would simply balloon the wing and then the upper and lower parts would go separate ways, similar to what happened to the P-38's wing tip in one of Gibbage's pictures on this page. The spar would remain intact.
I think characteristics would be similar with the ribs and rivets in place.

deepo_HP
11-27-2009, 02:08 AM
Originally posted by Gibbage1:
You have yet to show a FUEL VAPOR EXPLOSION...
We have no doubt that fires happen on aircraft. Thats not the topic. Stick to the topic, or please leave. gee, which kind of attitude are you representing here?
as a supporter of the topic's statement, YOU have to show ammo explosion in wings. by all the videos so far anyone can say what he or she thinks that explodes there. show some ammobox wing-explosion or stop asking others to disprove you!
'we' also have no doubt, that ammoboxes exploded. that's not the topic. the topic reads:'footage, 50 cal punches wings off fw190s easily'! the topic is ammobox exploding in wings of 190s by 50 cal hits, NOT many oversized pics of p-38s!
it looks to me as if you have made this thread to some personal vendetta against 'kettle' (as you like to call him sometimes). the fuel-argument had been brought on since page2 of the thread by several others, and you already stated on page6:
'a fireball. ...the only possible explination is the ammo.'
and you never changed that point of view!
on page10:
>>Originally posted by Kettenhunde:
>>There are lots of things that burn and explode on airplanes that have nothing to do with ammunition, Bill.
'Then what in a FW-190's wing burns and explodes besides the ammo?
If you say fuel vapor from the fuel tank, thats total bs.'

with all respect, you should honestly slow down!
i don't care about your relationship to crumpp, but - whatever attitude can be recognised by his posts - so far your language is quite inappropriate to me in some parts.
i say this, because i appreciated the information given in at least one post per page, may it have been by you, crumpp or anyone else. it might get heated at times, but i find it highly unnecessary to keep the flames up by effort!
'stick to the topic, or please leave'? unbelievable... so whom will you tell next, what the topic is?



Originally posted by Gibbage1:
Good find! Looks like there is yet more proof that 20MM ammo hits WAS a concern.

But it seems the people who didnt think so have left. maybe because you tell them to leave? or maybe, because it doesn't seem worth the effort to reply to your ever 'proof' - where i don't mean the content, but the hard to be argued fortification of claimed facts.

but i am still here and i try again, nevertheless:
there is no 'proof' in anything you have painted, frame-treated, quoted or similar for exploding ammo-boxes in the videos.
you consequently use 'proof' for what is (your) conclusion, assumption or whatever.
you find 'more proof' to what? to facts already 'proven' by you? how much 'proof' have you collected so far? take care, that you won't overproof your case!


there are theories, probabilities, possibilities, assumptions, all supporting this or that opinion.

what you are looking for is evidence, not 'proof'.
evidence is factual, that means it is by itself. it is not for discussion but commonly acknowledged fact.

however, you show not the slightest intention to reconsider your conviction, which you already have shown in your first posts. you collect and present all widely related information you can get and call it 'proof' - which it is not. they are arguments, or indications and not even hard evidence.

you are claiming to have 'more proof that 20mm ammo hits was a concern'? in this case, it is even not a point of discussion, probably merely mentioned by you to gather the largest 'collection of proof' in the discussion.
i can't see anywhere so far, that the 'concern of 20mm ammo hits' has ever been a topic here. of course we can assume there was concern! i would even say, the concern was about ammo hits in general!
the question is what was the reason for the concern, and what was the reason for (obviously) bigger concern about 20mm than small calibres, and what was the concern on the shown subvariants of planes only? which is exactly the main question. so far it has been suggested that it could be the danger of explosion, or the danger of jamming.

your fallacy is, that you argue like 'i know that ammo boxes explode, so protecting them makes sense and proves it' - which is at best an explanation for the armour but on your still unproven theory. it is not an evidence to deduce on proof and it is not even a good explanation - since the armour is only in front, not obviously (only) protecting for the ammobox, and not on all variants with 20mm cannon, like not in ground-attack versions shown by bremspropeller.

on the other hand, suggesting the risk of jamming when an ammo box gets hit is just that: an alternative explanation. 20mm is the preferrable ammo for intercepting, and hits on the ammo box (or connecting parts next to it) most probable interfere negative with belting or cannon, so protecting them to the front (where hits are to be expected when attacking bombers or ground targets) is sound. the overall value of interceptors can perhaps be assumed higher than fighters and jamming the cannons will render them highly ineffective, so general and overall protection of ammoboxes, -belting and/or cannon was perhaps considered of higher order than in fighter-versions.
there is no need for more than this suggestion, as long as you haven't shown any evidence! you have a theory of exploding ammo, so you have to provide evidence. any sound counterproposition will throw you back and there is not even a need for evidence on the counterargument!
this doesn't mean in any way, that your suggestion is wrong - but to make it true fact you need to provide the undoubtable. negating your theory doesn't make the alternative become true automatically... but i don't think anyone has claimed so.

nothing to say about a strong opinion, but for discussing different opinions it doesn't help to implicate that one's own theory is already the only possibility or every informational detail in arguments can be classified as 'proof'.

you posted on page20 your hope that ammo explosion will be modelled in future versions of the sim. this strongly indicates that you took it already as a fact before, and since then have denied to discuss anymore.

arguing against a conviction is like trying to debate a belief, which is the kind of show that i rather watch than participate.

Gibbage1
11-27-2009, 02:42 AM
Way too many words for me to bother reading.

The reason why I disrespect Crumpp is because of his post's. He post's photo's of dead animals, links to modern airline cleaner, talks about P-47 oil consumption, and rambles on about vapor explosions. Once confronted with evidence he tried to hide and deny, he went back and deleted all his post's. That right there is the reason I have 0 respect for him. You may think he is some sort of final word, but he's far from it.

BTW, think a little. If they protected the ammo box "just to protect the belting" then why not armor the gun? Any hit would disable the gun, yet only is ammo is? No. They protected the ammo to protect the pilot. Also, in the A8R8, why only protect the warheads if they are just protecting the belting? These things just dont add up, no matter what sort of slant you put on them. They are not protecting the belting!

Also, nobody has yet to provide proof of a vapor explosion far away from a fuel source. Yes yes yes, crumpp posted some worthless NTSB articals about engine fires, or cargo fires, but they all have 2 things in common. First, they have a fuel source, second, no explosion.

P.S. The ammo box armor was not MY therie, but people against the idea of it being an ammo explosion. There therie was "Well if ammo is so volitile, why dont they armor the ammo boxes?" and to that we have shown at least 4 differant aircraft with armor covering the ammo boxes. Now your saying its MY therie, and that its flawed?

I also think a fuel vapor fire would not be energetic enough to brake the wing spar. Blow off a panel? Yes. Cause wing failure? Maybe. Blow appart a spar? No. Also, I have provided "proof" that the wing IS vented, and thus unable to support enough fumes to create a critical situation. Your compleatly ignoring that now, arnt you?

BTW, I have proven time and time again to change my position if someone provides proof enough to convince me. So far nothing has been presented to even come close. Just a bust of wild asumptions about a far fetched fuel vapor gathering in a well vented wing. Thats a lot less likley then just hitting a 20MM shell and having it explode.

M_Gunz
11-27-2009, 02:49 AM
There are more than a couple members here who don't know logic from rhetoric because they can't deal with logic.
For those, a stack of arguments that can drive anyone who counters them constitutes proof, and the reverse is
also true that as long as they just hang in there they must be right.

Gibbage1
11-27-2009, 02:51 AM
I really dont know if you agree with me or not gunz. Thats rather cryptic, and can go both ways.

deepo_HP
11-27-2009, 04:39 AM
Originally posted by Gibbage1:
Way too many words for me to bother reading. then as well don't bother to reply to what you haven't read, pls...
besides, i don't think, i have any chance to get to the number of words you have already posted in this thread. just that i have read them all.

in that regard, probably way too many words will follow now. i don't care if you read them or not - i wrote them for my own wellness.


Originally posted by Gibbage1:
He post's photo's of dead animals, links to modern airline cleaner, talks about P-47 oil consumption, and rambles on about vapor explosions. the dead animal was in my opinion a direct (and quite funny) response to another post about the subtitle of the original video:
'I was laughing because . . . Geramns = Male Giraffe' (posted by doraemil, page4)
maybe the dead giraffe was off-topic, the same were the later following pics of milk-bottles.

the rest of his information was informative to me, maybe not always strongly related to the topic, but most times in reply to some others request (which were often the same not strongly related to the topic)


Originally posted by Gibbage1:
You may think he is some sort of final word, but he's far from it. i may think so, or i may not. doesn't matter at all, and not your business.


Originally posted by Gibbage1:
BTW, think a little. Any hit would disable the gun, yet only is ammo is?
is it so? i doubt that the gun is of the same sensitivity than the belt.


Originally posted by Gibbage1:
Also, nobody has yet to provide proof of a vapor explosion far away from a fuel source. and you have not provided proof of an ammobox explosion yet.


Originally posted by Gibbage1:
P.S. The ammo box armor was not MY therie, but people against the idea of it being an ammo explosion. There therie was "Well if ammo is so volitile, why dont they armor the ammo boxes?" and to that we have shown at least 4 differant aircraft with armor covering the ammo boxes. Now your saying its MY therie, and that its flawed? sorry, i wasn't very clear there. i was commenting specifically on that part of the whole discussion as an example. i didn't mean to picture you as constructing theories, just tried to make a point about my concern on claims of proof. my fault.
however, there wasn't many 'people' questioning about armour. if i remember correctly it was mainly one (sry, a bit late - i have to look it up). i appreciate that you take time and effort to give details on armour (one reason, why i read this thread is the amount of information to be found). but personally i already said my opinion on armour and i haven't asked about more.
so i don't consider your statement on concern about ammo (or whatever) protection not as flawed, but the value as proof on topic can not be concluded, imo. the protection can be reasoned in several ways.



Originally posted by Gibbage1:
Also, I have provided "proof" that the wing IS vented, and thus unable to support enough fumes to create a critical situation. Your compleatly ignoring that now, arnt you?. nope... i don't ignore anything. i am in all aspects of the discussion more in the range of likelyhoods, and i have the least opinion on fuel explosion as the reason for the effects seen. as i said above, my intention was to make a point on that: likelyhoods instead of facts.
but still sorry, i am never sure if i am only slightly capable of writing comprehensible...
for gasoline explosion power it is better to have a lower than a higher concentration of vapour. from 4.5% and higher on the gasoline will just make a little flame, maximum power would be at about 0.7%, below that it won't do anything.
so the question would be (if further discussed): is the concentration of fumes in these limits?


Originally posted by Gibbage1:
Just a bust of wild asumptions about a far fetched fuel vapor gathering in a well vented wing. i have good respect on your knowledge, and i don't want to seem getting personal by my posts. just to have it said.
but don't you think, that just this view on other arguments as 'just a bust of wild asumptions about ... fuel vapor' is most diminuating? not only is it wrong (as there are several more alternatives), it is pretty snobby. considering the footage that is the base for this thread, every conclusion is purely speculative.



Originally posted by Gibbage1:
I really dont know if you agree with me or not gunz. Thats rather cryptic, and can go both ways. there we are in agreement.
(not that i complain about gunz' cryptics, but they are better than mine)

RegRag1977
11-27-2009, 08:32 AM
Originally posted by Kettenhunde:
Interesting that lights are sealed units on airplanes....

http://www.aircraftspruce.com/.../positionlights.html (http://www.aircraftspruce.com/menus/el/positionlights.html)

Maybe we can make a graphic artwork depiction and see where it fits on the wingtip?

Maybe somewhere near the actual place called 5 feet away from any fuel http://forums.ubi.com/images/smilies/88.gif

BaronUnderpants
11-27-2009, 08:37 AM
So what DID happen to the P-38`s wintip?

RegRag1977
11-27-2009, 08:41 AM
Originally posted by JtD:
Would an explosion without shrapnel, for instance a fuel vapour explosion, be enough to destroy a wing spar?

I've been thinking about that, and consider it unlikely. For the simple reason that the pressure will go the way of the least resistance, through the thin aluminum sheets, and not through the most solid object in the area.

If the wing was a simple void object with a spar inside, meaning no ribs and rivets between ribs and wing surface, the explosion would simply balloon the wing and then the upper and lower parts would go separate ways, similar to what happened to the P-38's wing tip in one of Gibbage's pictures on this page. The spar would remain intact.
I think characteristics would be similar with the ribs and rivets in place.

Yes but it would mostly depend on speed and load factor. Wouldn't the spar break under high G and at high speed?


Kettenhunde said:



"If an airplane is under an asymmetrical load as in skidding or slipping turn its failure point is much lower. Load factor limits apply to one axis only.

Damage the main spar and the supporting structure it becomes very possible for the wing to fail at very low load factors as well.

During WWII it was determined that the best way to inflict the most damage to a monocoque construction airframe was by overpressure. You set off an explosion inside the structure. While the explosion might cause large areas of visible damage, it can compromise the structure without it. A few loose rivets in a load bearing structure are cause for concern. The over pressure tends to loosen large areas of rivet lines and seams. The effect is that our airframe is much weaker and cannot handle the level of stress it did before it was damaged."

JtD
11-27-2009, 09:01 AM
Yes but it would mostly depend on speed and load factor. Wouldn't the spar break under high G and at high speed?

Every spar can brake under high g, and certainly an explosion will help to cause its failure, be it with shrapnel or without.

My question was if the explosion with no shrapnel could/would take out the spar on it's own.

Gibbage1
11-27-2009, 11:31 AM
Originally posted by BaronUnderpants:
So what DID happen to the P-38`s wintip?

Unknown. I dont have the book it came from, and the caption is too vague. It looks like there is collision damage to the leading edge, but more consistant with low speed. Like he taxied into a pole or another aircraft. At high speed, it would be a clean sheer. The other posibility is a vapor explosion.

Gibbage1
11-27-2009, 11:32 AM
For those people who think its a fuel vapor explosion, a simple question. What evedence has anyone posted to support this idea?

M_Gunz
11-27-2009, 02:58 PM
How is it that a fuel tank explosion can blow up a whole plane but less can't take a wing off?

Gibbage1
11-27-2009, 03:11 PM
Originally posted by M_Gunz:
How is it that a fuel tank explosion can blow up a whole plane but less can't take a wing off?

It really depends on location and ammount. If your refering to the large jumbo jet that had a fuel tank explode, look at the construction and location, and also ammount of fuel/volume. From what I recall, the tank was empty, sealed, and full of vapor. Prime area for an explosion. Also, it was in the belly, next to more fuel tanks. The aircraft was also stress skin construction, so it did not rely on beams for its structure, but the skin itself.

It was a massive explosion in the belly of (I think) A 747 in the middle of a bunch of fuel tanks. Vastly differant from the therie of a little fumes lighting up in a wing away from fuel.

I still ask the question, what proof is there that its fuel vapor? What convinced people that its not ammo, but fuel vapor?

deepo_HP
11-28-2009, 12:45 AM
Originally posted by Gibbage1:
... and also ammount of fuel/volume. From what I recall, the tank was empty, sealed, and full of vapor. Prime area for an explosion. i think, that depends. fuel will only(!) explode, if the volume-percentage of vapour in air is between 1%-7.5%. below it won't do nothing at all, above that percentage it will just burn or the same do nothing.

a sealed fuel tank is usually saturated with vapor. the vapor produces an overpressure, so air won't get in even with some (small) holes - cars need a valve for venting therefor so the tank keeps it's shape. generally speking, a fuel tank is pretty safe from explosions and won't even burn on ignition.
i would guess, it starts to be dangerous, when air is forced into the tank (by turbulence perhaps) or when the vapor gets from the tank in another already compartment filled with air.
that is the very reason that a well vented compartment is indeed much more dangerous , if there is leakage coming into it, or any other source of vapor. it comes down to the size and structure of the compartment. if it is not too big and any holes in it are not big enough to give the detonating gas an exit, the vented compartment will deliver a nice blast... 1% of vapor is pretty soon established.

fuel tank explosions are probably a rare case at all. i could imagine, that the fuel tank is a risk when it leaks (or some air gets in) and the fuel starts spreading or burning to other compartments. the flammability will rapidly increase if air is available.
imo, leakage of fuel from the tank into other compartments is the risk, rather than the fuel in the tank itself.

in case that the fuel tank is empty (with liquid fuel) for a longer time already, it is quite possible of course, that air leaked in (or vapor out). since it had been in use and was reliably sealed as said here, but just run empty, i'd say that nothing happened at all inside the tank.


just to be sure that there will be no misunderstandings... i know much too less on construction of planes and compartments to have an opinion on vapor explosions (well, i said that already).
what i said is just on tanks and vapors to clear that up.

in regard to your question to the audience... i just consider ammo explosion unlikely, and very unlikely that 50 cal can cause it. i also don't try to interprete some few stamp-like youtube videos to come to surprising results like 50 cal explode ammo in 190s.
that is all.

reading about the general saftey, the belting and the protection of ammo is still very interesting to me. also the evaluation of possible risks from fuel tanks, fuel vapors and fuel leakage is!
(i think i said this before, too. but anyways... i thought it won't hurt to make the statement again. and in case of too many words i have out it at the end)

Gibbage1
11-28-2009, 01:30 AM
Currently, all airliners backfill the tanks with normal air. That means O2 is introduced into the tanks, creating a deadly mix. Only the 787 is planned to have a nitrogen-inerting system, to nuteralize empty tanks from explosions.

What do you consider more likley though? Ammo explosion from 50 cal, or random fuel explosion in a well ventilated wing 5 feet away from the fuel? I still have yet to see any proof to the fuel vapor therie.

deepo_HP
11-28-2009, 03:33 AM
hi gibbage,


Originally posted by Gibbage1:
What do you consider more likley though? Ammo explosion from 50 cal, or random fuel explosion in a well ventilated wing 5 feet away from the fuel? if you refuse to read what i post, that's ok to me. i am fully satisfied with pretending to myself that others read my replies.
but please stop asking questions which i have already answered many times!

seriously, that starts to get embarassing...



Originally posted by Gibbage1:
Currently, all airliners backfill the tanks with normal air. That means O2 is introduced into the tanks, creating a deadly mix. Only the 787 is planned to have a nitrogen-inerting system, to nuteralize empty tanks from explosions. on topic of your reply:
so, currently all airliners are backfilling the tanks with air? that is interesting, what is the reason to backfill with air?
how and when do they do it?

by memory, ventilation was (and partially is) considered a possible action to get rid of vapors in dry bays and surrounding areas to tanks, not tanks themselves. it was (and partially is) done by actively replacing all vapor with non-vaporised air - with the intention to have no explosive mix in the surrounding compartments.
(only to make a note: this is different from 'venting', which releases the overpressure of vapor inside the tank by valves.)

if you have knowledge of the means of backfilling tanks with air, like creating explosive mix in the tank, i would very much appreciate a hint where to look for it. i am sure, it is just my only basic level of comprehension, which made me find it not necessary to add oxidant to falammable vapor in a closed chamber.


from Fuel Tank Harmonization Working Group (http://www.fire.tc.faa.gov/pdf/EXECSUM.pdf) (in reaction to TWA 800), 1997:
'For fuel vapor reduction, five of the options considered reduce the exposure to flammable fuel vapor. These are: Insulate the heat source adjacent to fuel tanks;
Ventilate the space between fuel tanks and adjacent heat sources;
Redistribute mission fuel into fuel tanks adjacent to heat sources;
Locate significant heat sources away from fuel tanks;
Sweep the ullage of empty fuel tanks.

Only directed ventilation and relocation of the significant heat sources reduce the exposure to an acceptable level.'

the Department of Transportation's Secretary Mary Peters said 2008 (http://www.npr.org/templates/story/story.php?storyId=92602014), that 2,730 airbuses and boeings need to be fitted with a technology, which
'will make fuel tanks less combustible by sucking out the oxygen.'


in my understanding that means, that ventilation is not considered a good idea for making fuel tanks less explosive.
i would be thankful, if you could convince me, that it is (or at least was) considered to ventilate or backfill fuel tanks with air for saftey reason.
this just as a personal favour, since i don't think, we shouldn't bother much about modern airliners and their many engines.

and - just to reiterate - my point is not about fuel tanks being as safe as everyones bathroom... my point is that a sealed tank full of vapor is NOT a prime area for explosion, much like an old fashioned toilet is not (<- trying to make a joke to light it up a bit... oh well, not lterally).
my point is, that fuel is a risk of explosion if the mix is right and if there is a chamber - in that regard a fuel tank is not more dangerous than any vaporised compartment, in fact, i think a fuel tank is for most of the time less a risk to explosion than other compartments with leaked fuel.
so i am ok with discussing any kind of vehicle, if there are some which get air added to vapor by purpose.

M_Gunz
11-28-2009, 04:17 AM
Many countries during WWII vented CO2 or other inert gasses into the fuel tanks. Russians used cooled exhaust
fumes. That is how much danger there is of fuel tank explosions. The Mk108 incendiary shell had a special
fuse that would only go off when immersed in liquid just to destroy fuel tanks and cause fires/explosions.

Car gas tanks are coated with non-sparking materials and other precautions made against explosions, the last
notable exception I know of was the Ford Pinto that actually did explode in some rear-end collisions.

You can smell gas pretty strongly without being in danger of lighting it off. I've been in enough garages
with nicotine addicts to know that. As long as the big door is open it's -usually- safe, LOL!

On a side note I did know one guy who told about sniffing gas fumes when he was a kid. I asked him why and
he said it was to hear the oooomi-oomies just before passing out. It was something a grade-school friend
taught him. Working on models in closed rooms probably isn't much better at least with the old glues, dopes,
spray paint or other things with toxic fumes. It's a certain way to lower the old IQ, at least as good as
heavy drinking!

deepo_HP
11-28-2009, 05:12 AM
hi m_gunz,

what are 'oooomi-oomies'?

i remember the quite new ink-killersticks when i was in 5th or 6th grade. they weren't like the filthy, penlikes nowadays, they looked like more like lip-sticks... screwing them up revealed a whitish wax, which (it said) should be moistenised by water and drawn over the ink then, so it vanished.
of course it was forbidden to use them in first order - even if it could be clearly seen anyway.
as a result everyone got an inkkiller-stick and naturally there was rarely a water-source nearby. so the stick was licked - and it tasted like wax.
teachers are clever, and they told us the sticks were poisening us. however, teachers are also dumb, dumber than anyone else to talk to low-graders... so we tested the poison. and we suddenly dound, that the sticks tasted different. and we felt a bit dizzy... and heard voices.
probably not a bit truth in what we thought to experience, but the sticks were empty in a quarter of the time.

i never did fumes or glue... so what is 'ooooomi-oomies'? if it is poisoning, i need to try!

BaronUnderpants
11-28-2009, 06:53 AM
Personally, i havent desmissed the idea that the Fw got hit with 20mm shells.

Havent dismissed any of the possibilitys really, not enough evidance though, to prove any of them no matter how much we would like to.

Kettenhunde
11-28-2009, 07:36 AM
imo, leakage of fuel from the tank into other compartments is the risk, rather than the fuel in the tank itself.

Exactly. Every time a self sealing tank is punctured, it is equal to throwing a bucket of gas into the compartment due to the self seal process.

RegRag1977
11-28-2009, 08:51 AM
Originally posted by BaronUnderpants:

Havent dismissed any of the possibilitys really, not enough evidance though, to prove any of them no matter how much we would like to.

Yep, that's it http://forums.ubi.com/images/smilies/25.gif

M_Gunz
11-28-2009, 09:02 AM
Originally posted by BaronUnderpants:

Havent dismissed any of the possibilitys really, not enough evidance though, to prove any of them no matter how much we would like to.

Does anyone need to be an expert to understand this? Doesn't seem like it.

JtD
11-28-2009, 10:48 AM
It's physically impossible that all of the explosions were fuel vapour explosions. I said that because I know. Vapour explosions don't last as long as some of the ones in the clips did and are not limited to a small portion of a wing.

I don't get why you're still at it.

yuuppers
11-28-2009, 11:07 AM
Originally posted by JtD:
It's physically impossible that all of the explosions were fuel vapour explosions. I said that because I know. Vapour explosions don't last as long as some of the ones in the clips did and are not limited to a small portion of a wing.

I don't get why you're still at it.

Because some people think they are experts because they have a pilot's licence and have one dimensional myopic tunnel vision.

Gibbage1
11-28-2009, 02:14 PM
I still havent seen anyone post any sort of proof that it was fuel vapor.

M_Gunz. You said CO2 was used with other inert gasses into fuel tanks. Do you understand that the FW-190 was being supplied with a constant pump of CO2? Exhaust was pumped into the wings as a gun heater. Wouldent that not only put displace vapor, but also make it inert?

TS_Sancho
11-28-2009, 03:11 PM
Exhaust was pumped into the wings as a gun heater. Wouldent that not only put displace vapor, but also make it inert?

Enough CO2 buildup from exhaust gas ducted to the gunbays for heating and the well vented wings you were insisting prohibited fuel vapor ignition is contradictory.

You cant have it both ways.

deepo_HP
11-28-2009, 04:11 PM
hi jtd,


Originally posted by JtD:
I don't get why you're still at it. is this adressed to me?
i guess not - because i am not at it. i have an indifferent opinion.


but i would still like to reply just on your argument:
Originally posted by JtD:
... because I know. Vapour explosions don't last as long as some of the ones in the clips did and are not limited to a small portion of a wing. i don't 'know' that much or what it is in the clips.


fuel most likely won't detonate, but deflagrate with lower speed of some 300m/s (?). a flame, the colour/turbulences and the overall duration should depend mainly on the vapor-mix and the amount of non-vapor left.
propagation would depend, but can hardly be concluded.

nitropenta detonates with 8,400m/s and at 4,000+. should have no flame, i guess. perhaps one very short, very bright flash.
i would say that a chainreaction in an ammobox will have an effect, which visually appears larger, but hardly longer.

propelling charges deflagrate slower as well, but calculated. probably a whitish flame of ~800C.


the above is only my wild approach on how the explosions could be like by their origin: a visible flame/flash comes from the reactive zone - any such visible effect longer than few milliseconds is not by detonation, but deflagration. if a 'flame' has a visibly defined dimension it probably shows the flammability border of vapor-mix (rather than from a deflagrating charge which contains the oxidant already).
additonal visible effects could be provided by some other reactions with metal or structure and of course the dusty remains of what has been the wing.
i don't consider the videos appropriate enough to conclude on the origin of explosion by the visible effect (my main point).

would you tell me the details you know, so i can find my mistake, pls?

yuuppers
11-28-2009, 05:39 PM
Originally posted by Gibbage1:
I still havent seen anyone post any sort of proof that it was fuel vapor.

M_Gunz. You said CO2 was used with other inert gasses into fuel tanks. Do you understand that the FW-190 was being supplied with a constant pump of CO2? Exhaust was pumped into the wings as a gun heater. Wouldent that not only put displace vapor, but also make it inert?

Sorry Gibbage but that is not true. Hot air was ducked from the lower outboard exhaust pipe using a shroud on the respective side to the outboard ammo.

Kettenhunde
11-28-2009, 05:58 PM
ducked

goosed...

http://forums.ubi.com/images/smilies/partyhat.gif

M_Gunz
11-28-2009, 06:01 PM
Only when it's miles over your head during migration. Otherwise it's just ducked.

yuuppers
11-28-2009, 06:02 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">ducked

It was ducked huh?

Is that like goosed? </div></BLOCKQUOTE>

Oh, the spelling gestapo has arrived. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

ducted > is that better TROLL

M_Gunz
11-28-2009, 06:38 PM
Went right over somebody's head... miles over.

Gibbage1
11-28-2009, 08:48 PM
The fact that there is air being enduced into the space means there must be a way out, thus vented.

I still havent seen anyone post what evedence convinced them its fuel vapor.

JtD
11-29-2009, 12:05 AM
Originally posted by deepo_HP:

fuel most likely won't detonate, but deflagrate with lower speed of some 300m/s (?).

A fuel vapour will explode at speeds around 1500m/s. If it just burned at 300m/s, it would not be an explosion and thus fail to do a serious amount of damage.
Fuel vapours burn at once, meaning a fuel vapour explosion going through a FW from wingtip to wingtip would last less than 1/100th of a second. And all you'd see is boom. You wouldn't see successive explosions in roughly the same spot. And it would go through the entire plane, since there's no way to restrict fumes to a small portion of a wing that has no fuel source. They would need to get there somehow, so they'd be everywhere and the plane would be torn to pieces almost entirely, not just have a hole blown into the wing.

And no, my post wasn't directed at you, at least not in particular.

It's more likely the that explosions were a collision with an invisible alien spaceship than a fuel vapour explosion. I'll also bet than no one can disprove that theory. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

peterdwb
11-29-2009, 03:00 AM
Originally posted by JtD:
It's more likely the that explosions were a collision with an invisible alien spaceship than a fuel vapour explosion. I'll also bet than no one can disprove that theory. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif
Invisible alien spaceships only fly during the night UNLESS it's over US territoy. Cold hard fact. http://forums.ubi.com/images/smilies/shady.gif

http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Gibbage1
11-29-2009, 04:03 AM
Originally posted by yuuppers:
Sorry Gibbage but that is not true. Hot air was ducked from the lower outboard exhaust pipe using a shroud on the respective side to the outboard ammo.

Thanks for the correction. I read your previous post incorrectly in the old thread. I guess then it works like the P-38 cabin heater. Question is, how is the air forced into the wing? Is there high pressure behind the engine due to the fan? In the P-38, there is a duct on the boom that uses RAM air to force the air into the cabin, but the heating duct on the 190 is located inside. If the wing was sealed enough to allow fumes to gather, then there would need to be a significant pump hay? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Xiolablu3
11-29-2009, 05:12 AM
Originally posted by yuuppers:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">ducked

It was ducked huh?

Is that like goosed? </div></BLOCKQUOTE>

Oh, the spelling gestapo has arrived. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

ducted > is that better TROLL </div></BLOCKQUOTE>

Yuupers you complain to me in private about other members, but are one of the main offenders.

If you guys cant discuss this in a civil manner then one of us will lock the thread. (thought about it this time, but will give it one more chance as its full of interesting info, despite the arguing)

I would think its an ammo box explosion, but we will never know for sure.

deepo_HP
11-29-2009, 05:17 AM
hi jtd,


Originally posted by JtD:
A fuel vapour will explode at speeds around 1500m/s. If it just burned at 300m/s, it would not be an explosion and thus fail to do a serious amount of damage. wrong.
seems you were too fast on the reply or too self-confident (my guess on likelyhood here is better for the latter)

anyhow, here my reasoning for your erratic facts.
i was quite careful with my technicalwording before, mainly because i had no clue about the english terms to use.
silly me! for once i could have used wikipedia, it was only for the term...

but now i did. and i saw, that indeed 'deflagration' is the very same word in english. hooray.

it seems to me, that you should do the same. maybe just try now, since you just showed flat and unspecific or wrong statements.
the following is a summary taken from the results of a search for 'deflagration', 'combustion', 'explosion' and 'detonation' in english wikipedia. perhaps we can use it as a common base - even if from wikipedia.
what i posted before says the same, but was taken from my dusty 'physikalische chemie' (atkins & hpfner, 2nd edition)


'explosion' describes the effect of rapid increase of volume creating a shockwave. if the shockwave is supersonic, it is called 'detonation', if it is subsonic 'deflagration'.
(so far you are just using the wrong words... not from wikipedia, but my comment).

now for 'combustion', which is only the term for the reaction of ignitible gase with oxidant.
a 'combustion' can be either of the 'deflagrating' type, that is subsonic spread of the reaction front, or of the 'detonation' type, when the flame goes supersonic.
well, the detonation type of combustion propagates through shock compression. the main mechanism is 'of a powerful pressure wave that compresses the unburnt gas ahead of the wave to a temperature above the autoignition temperature'.
(my comment: the process needs high pressure and is self-igniting, so not in our interest.)

under certain conditions, mainly in terms of geometrical conditions .... that cause turbulent flame eddy currents, the flame may accelerate to supersonic speed, so called 'deflagration to detonation transition'. the exact mechanism is not fully understood.
(my comment: the process starts as deflagration and needs therefor longer than detonation of high explosives)


ok. thats for the basics. now it is all my commentory again (with more sloppy wording) http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

few things, just for comparison:
the process in low-explosice charges like propellants, is a deflagration, too. also blackpowder deflagrates with 340m/s. despite the belief you have shown in your controversal reply, the damage does not correlate directly to speed of explosion.


so, besides a not really ingenious joke, by the last post you have only shown, that you have not much of a clue what you are talking about fuel-explosion. am i right? i think so.


i am quite allergic to this kind of half-wits, jtd.
i had only a low memory of some of the subjects, so i had take some time for my posts. all of the fuel-vapor stuff was not even a thing i had an opinion on. what i posted was therfor all in direct reply to you or gibbage.
i am not too sensible in language terms or rhetorical tricksies.
just wrong statements in easy thrown and fast written posts leave me with a dull taste of the poster's overly self-esteem with me.

but probably i can learn to handle that irritation. i'll start by taking your posts as opportunistic reflexes. no offense intended, it is just for my own good.

BillSwagger
11-29-2009, 06:44 AM
I think a fuel vapor explosion is possible, but thats not what we are seeing in the footage.
I realize that what we get from the footage is very limited and so we must rely on other information to formulate a conclusion or hypothesis on what is occurring.
I realize not everyone is going to agree so easily, and it might take much more fact finding before anyone says "yes, that's what it is."
Otoh, i am using a bit of common sense, and having a better understanding of what is occurring in the footage, as well as the possible components involved. In my view, there is more information that points to ammo detonation than fuel explosion. A lot of what is occurring in these shots is also very consistent. We see similar explosions, in same section of the wing, for a similar duration. A fuel explosion is possible in this section of the wing, but i just don't see these results coming from such an explosion.

Apart from the obvious, i'm just trying to piece this together, and see how fuel could explode in such a way with out also igniting other parts where the fuel would need to leak from. If we are to suggest that fuel is in the wing to explode, then what we are seeing in the footage is inconsistent with how fuel ignites and spreads as well.

I said this earlier, if i let a can of fuel leak fumes, and then light the end away from the can, what do you think would happen?
Wouldn't the end i light also ignite the fuel all the way to the source of the leak, and possibly the contents of the can depending on the hole?
we might consider mixture, but even if the air content is low, then we should still see more fire burning the rest of the fuel or fumes off, rather than a puff of smoke and the wing separating.

I apologize if that has already been answered, i have only read the last few posts, but it seems we are still at this point with regards to a fuel fire or explosion.


Bill

JtD
11-29-2009, 07:06 AM
deepo_HP, I think my statement was worded well enough to get my point across, nonetheless, if you feel it's necessary to agree to particular definitions we could use the DIN 14011:2005. Considering your looking at "Phyiskalische Chemie", you shouldn't have a language problem.

Blackpowder explodes at varying speeds, depending on the composition and the conditions. Everything between 300 m/s and 1000 m/s being possible.

As to my "believes" about speeds being important regarding the explosive power - they are. I did not say anything about a direct correlation, you made that up. In fact, the point I was making here, though not spelled out, is a matter of subsonic or supersonic pressure transfer. Added to that, a higher explosive velocity is beneficial to the damage done, no matter what you say. That's why low explosives are not used for projectiles.

And while you so blatantly stated that I am wrong, you essentially didn't contest a thing I said. Well, except for pointing out that subsonic burning is also considered an explosion.

If you wish to continue to debate, feel free to ask for clarification about what is written, but please stop making assumptions about what it could be and stop making assumptions about the poster. The latter is against forum rules, and I've had enough of this.

... Adding a little narrative illustrating the importance of exact definitions and the real life use of them, the Airbus A380 had to have the structural strength tested. This included overpressurising it to simulate high altitude. Now overpressurising a giant volume like this harbours some dangers, a catastrophic failure could mean disaster to the testing lab. So it had a blast wall and a rather large safety zone beyond it. The scenario where the A380 would blow, was colloquially called "explosion", without even a combustion taking place. Still everyone would know what was meant by that.

M_Gunz
11-29-2009, 07:37 AM
The burning at least partly depends on the mix of fuel and air, also the temperature.
As for the flashes in the grainy video, they could just as well be incendiaries hitting.

Could be is not the same as must be. Coming to a conclusion when there is not enough to
base a conclusion upon is the basis of rumor and gossip, certainly not proof or knowing.

Gibbage1
11-29-2009, 04:02 PM
I still have yet to see anyone post as to why they are so convinced its a fuel vapor explosion.....

BaronUnderpants
11-29-2009, 05:40 PM
PM me and let me know who "wins" the debate. http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

TS_Sancho
11-29-2009, 06:04 PM
I had a friend over yesterday who has a working background in things that go boom and coincidently restores firearms as one of his hobbies.

While we were shooting the breeze I brought this thread up and asked him if he minded offering an opinion. His take was that its impossible to tell whats going on in the youtube gun camera footage, there isnt enough there and the quality is poor.

He did say that in his experience the chances of a .50 caliber round detonating the cannon rounds or setting off the propellant were very remote and that fuel would be his best guess.

Gibbage1
11-29-2009, 10:29 PM
Originally posted by TS_Sancho:
He did say that in his experience the chances of a .50 caliber round detonating the cannon rounds or setting off the propellant were very remote and that fuel would be his best guess.

Did you forget to tell him there was no fuel in the wings?

JtD
11-29-2009, 11:41 PM
Interestingly, PETN, the explosive used by the Germans in their projectiles, is rather sensitive to shock, friction and temperature.

An AP round carries enough kinetic energy to set fire to PETN - if all the kinetic energy was converted to thermal energy into the round itself, as would happen if the round was to hit a solid armor plate. Likewise, it is definitely capable of producing splinters hot enough to ignite PETN.

Additionally, the burning temperature of incendiaries and tracers is hot enough to ignite PETN, though one has to wonder if a very short exposure (in particular with the PETN inside a metal shell and the incendiary outside) would do anything.

Regarding shock and friction, I haven't been able to find reliable numbers yet, but I don't think it is far fetched that a .50 AP round is good enough to set PETN off by either of those, too. It's not like RDX or TNT. Feel free to look for yourself.

M_Gunz
11-30-2009, 01:36 AM
If you can hit the projectile square enough from close enough that after breaking through to the shell
there is enough kinetic to break through the thin wall shell without just pushing it through whatever
holds it (or fast enough that inertia of the shell alone is enough) then certainly it should explode.

Those same shells can take acceleration to reach muzzle velocity in a barrel length and heat of being
fired but compared to a 50 cal at 1400 ft/sec stopping in 20mm or less that is gentle. But then what
is going to -stop- the 50 cal in this case when it is fired from the 7 or 8 o'clock of the shell?

When the ordnance guys shoot unexploded shells to detonate them, are they set against a solid wall or
stop of some kind? Having that kind of "motion ends here" anvil to put the hammer to makes a difference.

I am pretty sure it should be possible but some Mythbusters type fieldwork seems in order, just for fun!

Kettenhunde
11-30-2009, 05:13 AM
Interestingly, PETN, the explosive used by the Germans in their projectiles, is rather sensitive to shock, friction and temperature.


This is what I mean by leaping to conclusions without facts.

PETN is shock sensitive if it is not mixed with a proper binder, hence its classification as a "plastic bonded" explosive. It is not practical or usable in the test tube form.


Secondary explosives can be loosely categorized into melt-pour explosives, which are based on nitroaromatics such as TNT, and plastic-bonded explosives which are based on a binder and crystalline explosive such as RDX.

http://www.globalsecurity.org/...tions/explosives.htm (http://www.globalsecurity.org/military/systems/munitions/explosives.htm)

I can't wait to see what you guys come up with next.

Bremspropeller
11-30-2009, 06:15 AM
Interestingly, PETN, the explosive used by the Germans in their projectiles, is rather sensitive to shock, friction and temperature.

So you imply that a HE-round being hit by a cal-50 being is gonna be fused, while the same HE-round, going off and down the barrel wouldn't fuze? http://forums.ubi.com/images/smilies/compsmash.gif

BillSwagger
11-30-2009, 06:33 AM
Originally posted by Bremspropeller:
So you imply that a HE-round being hit by a cal-50 being is gonna be fused, while the same HE-round, going off and down the barrel wouldn't fuze? http://forums.ubi.com/images/smilies/compsmash.gif


Common sense tells me the explosive content (not the detonator) of the shell is going to be much less sensitive to impact and heat. It needs to be carried and transported, as well as accelerated down the barrel. It might also need to withstand being dropped on the ground, although i'm sure personnel were advised to never drop any ammunition and be cautious when handling those types of items.


I already mentioned that the detonators were probably more sensitive to compression rather than impact. Its the crushing of the detonator by the firing pin that sets it off. A 50 cal bullet hits the shell and smashes the wall into the detonator which is enough compression to activate the detonator. The impact itself would probably do little harm to the explosive, but its the crushing and compression of the detonator that sets it off.



Bill

BillSwagger
11-30-2009, 06:40 AM
Originally posted by JtD:
Interestingly, PETN, the explosive used by the Germans in their projectiles, is rather sensitive to shock, friction and temperature.



I liken the use of that explosive to the use of nitro glisoren. Very sensitive to fluctuations in temperature as well as shock, or shaking. Many early chemists found out the hard way. Point is, that explosive is used in the blasting caps for shell casings, however it uses a binder to make it much more stable and practical to use outside of a chemistry lab.


Bill

M_Gunz
11-30-2009, 09:34 AM
Brems figure out shell acceleration down a half-meter or more of barrel vs bullet dead stop in 20mm or less.
It is orders of magnitude. That's why I wrote what I did in my post above.

Simple fact in gun shells that the depth of TNT or other in direction of acceleration can only be so deep
so the explosive doesn't squeeze itself into detonation does limit how much can be packed into a shell
with X-amount of said acceleration. With high speed guns I've read 10% of shell weight is usual.

BTW I see the detonator, not the charge, as the sensitive part. Usually it is mercury fulminate.

M_Gunz
11-30-2009, 09:39 AM
Originally posted by BillSwagger:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
Interestingly, PETN, the explosive used by the Germans in their projectiles, is rather sensitive to shock, friction and temperature.



I liken the use of that explosive to the use of nitro glisoren. Very sensitive to fluctuations in temperature as well as shock, or shaking. Many early chemists found out the hard way. Point is, that explosive is used in the blasting caps for shell casings, however it uses a binder to make it much more stable and practical to use outside of a chemistry lab.


Bill </div></BLOCKQUOTE>

Nitroglycerin is NOT used in blasting caps. Mercury fulminate is. Nitroglycerin set off by a blasting cap makes
a much bigger bang than nitroglycerin set off with say, a hammer. Alfred Nobel who invented the stuff did many
demonstrations to show how it is safe and how not but I think you read up on him and those as you wouldn't believe
me just describing those.

Bremspropeller
11-30-2009, 09:41 AM
Brems figure out shell acceleration down a half-meter or more of barrel vs bullet dead stop in 20mm or less

There is no "dead stop" within 20mm.

deepo_HP
11-30-2009, 09:46 AM
Originally posted by JtD:
... stop making assumptions about the poster. The latter is against forum rules, and I've had enough of this. sorry for that. sometimes i become a bit theatralic - my apologies...

JtD
11-30-2009, 10:38 AM
Originally posted by Bremspropeller:

So you imply that a HE-round being hit by a cal-50 being is gonna be fused, while the same HE-round, going off and down the barrel wouldn't fuze? http://forums.ubi.com/images/smilies/compsmash.gif

Yes, I do. Only that I did not say "going to", I mentioned the possibility.

I also said something more specific about heat, not shock.

I'd also like to point out that the shell will still blow if it hits a plane with a rather slow relative velocity, which in terms of shock is certainly not stronger than being hit by a .50 cal. In fact it will also blow if a tiny spring pushes the pin into the shell. Difference would be that these mechanism will work through the fuse, not on the explosive right away. However, the fuse also has to survive the acceleration down the barrel, a large part of it in "hot" condition.

JtD
11-30-2009, 10:40 AM
Originally posted by deepo_HP:
sorry for that. sometimes i become a bit theatralic - my apologies...

No problem anymore. Thanks.

JtD
11-30-2009, 10:46 AM
Did you know that fuel vapour, depending on the mixture and compostion, will only create between about 5% and 50% extra volume in the process of combustion? That is after it cooled down, so you'll initially have quite a bit more to cope with. Still, even when considering this, if there was a local fuel vapour accumulation in the wing of say 0.5 m volume, you wouldn't see explosions as large as 50 m in size (ball with about 4.5m diameter). Just doesn't happen.

M_Gunz
11-30-2009, 11:31 AM
Originally posted by Bremspropeller:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Brems figure out shell acceleration down a half-meter or more of barrel vs bullet dead stop in 20mm or less

There is no "dead stop" within 20mm. </div></BLOCKQUOTE>

Put the shell against the side of a tank. Shoot it with a bullet. Compare to acceleration in length of a barrel.
Sure, energy is taken away by broken bullet smearing off to the side but object hit gets most of it in short time.
Compare to being fired up length of a barrel, the latter is gentle.

TS_Sancho
11-30-2009, 11:44 AM
Originally posted by Gibbage1:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by TS_Sancho:
He did say that in his experience the chances of a .50 caliber round detonating the cannon rounds or setting off the propellant were very remote and that fuel would be his best guess.

Did you forget to tell him there was no fuel in the wings? </div></BLOCKQUOTE>

I am by no means offering his observation as any kind of absolute proof, as others have pointed out there is no way to tell in the videos.I only bothered to post his opinion because he has spent the last 30 of his 50 odd years handling explosives and was nice enough to read through 40 some pages of internet forum to see if he could help shed some light on the matter.

If it makes you feel better he also questioned Crumps assertion that if the rounds were detonated in the ammo box the explosive force would detonate them all rather than just blowing up one and scattering the rest.

Gibbage, I don't have any agenda in this and I am certainly not trying to discredit you in pursuing this discussion. If I have given you that impression by disagreeing with your conclusions I apologize as that was not my intent.

Gibbage1
11-30-2009, 12:42 PM
I really dont think its just impacting the shall that is setting it off. There is much more at play then shock. There is also compression and heat added to the shock. Any time you rub metel to metel, it generates significant heat. Also, the bullet will expose the explosive content of the shells. Your also forgetting a second accellerant stored in the shells. The gun powder.

Lets just say 1 shell exploded. That shell will rip open a lot of the brass casings holding the gun powder, and that alone should be enough energy to rip off the wing.

It could be we are seeing the gun powder going off, not the shells itself. Also, if there was exposed explosives, would the gun powder have enough heat to detonate it?

Also, accellerating down a berral is differant shock. It also doesent have compression, and the heat last's such a short time it wont get through the metal casing.

Also keep in mind the VT fuse shell had vacuume tubes in it. Those vacuume tubes could survive being fired, but would not survive the shock of being hit.

Bremspropeller
11-30-2009, 03:59 PM
Reading Gibbage's posts is like "treasure Island" for grammar-mossad people.

Gibbage1
11-30-2009, 04:13 PM
Originally posted by Bremspropeller:
Reading Gibbage's posts is like "treasure Island" for grammar-mossad people.

Grammar-nazi aside, do you think the gunpowder could be a possible source of the explosions?

Also, didnt the German's use RDX in some of there ammo instead of gun powder?

deepo_HP
11-30-2009, 04:18 PM
hi jtd,


Originally posted by JtD:
Did you know that fuel vapour, depending on the mixture and compostion, will only create between about 5% and 50% extra volume in the process of combustion? stochiometrically, 1kg gasoline burns to 3kg CO2.

i tried a rough calculation on the example of gasoline deflagratiion in otto-engines:

gasoline in combustion engines is injected with 7% (mass) of gasoline.
density of gasoline is 0.78kg/l, density of air is ~1.2kg/l
per liter combustion mix that is 0.08kg gasoline

0.08kg gasoline burn to 240g CO2
density of CO2 is ~2kg/m^3
240g CO2 is 0.12m^3=120l

in this process, 1 liter of fuel vapor results in 120l of CO2.
which is 11,900% expansion of volume.


i might be, that i have made a mistake? like i have only found values for 0 or 15, so volumes might be different - but shouldn't be dimensional.

Bremspropeller
11-30-2009, 04:19 PM
Well, if it's up to what I think:
There's lots of stuff that can go off.

I can't imagine a round going off by mere contact.
Maybe a cartrige-explosion that triggers the HE to go off?

Gibbage1
11-30-2009, 04:35 PM
In a car engine, you have the most optimal conditions for combustion. Heat, compression, and mixture. None of those properties exist in the wing. Here is the type of explosion you get with just fumes.

http://www.youtube.com/watch?v=u5-xS9sDuLg

It didnt even blow appart a plastic lexan case, yet it ripped the wing off of a FW-190? Really?

deepo_HP
11-30-2009, 04:41 PM
hi gibbage,


Originally posted by Gibbage1:
Also, didnt the German's use RDX in some of there ammo instead of gun powder? rdx is made of hexogen, which is one of the highest explosives known. it was used as a charge in 30mm shells, woth nitropenta and tetryl (or penthrite) as detonator.
'rdx' means, that the hexogen is phlegmatised with ~10% vaseline, as one of the first plastic-explosives. it became highly shock resistant by that - and hexogen itself is already very heat-resistant already... exposed to heat it just decomposes without detonation.
gun powder is a low explosive and was used in propellant charges, for example the 30mm mk-108 ammunition had a mixture of 30g rifle powder and 29g nitrocellulose.

Kettenhunde
11-30-2009, 05:10 PM
It didnt even blow appart a plastic lexan case,

http://forums.ubi.com/images/smilies/partyhat.gif

M_Gunz
11-30-2009, 05:15 PM
This is the stuff that will drive a loaded car how many miles per gallon at 60 mph?
Of course that's only because the only possible answer is exploding ammunition!

M_Gunz
11-30-2009, 05:24 PM
Originally posted by Gibbage1:
Also, didnt the German's use RDX in some of there ammo instead of gun powder?

Oh wow! A real ordnance expert! The Germans used _gunpowder_ in their _shells_ during WWII, but sometimes RDX!

Gibbage1
11-30-2009, 05:31 PM
Gunz. Do you read ANYTHING I type, or do you just hit the "reply sarcastically" button every time I post? I asked a question. I didnt make a statement. BTW, it was CORDITE I was thinking of, and it was used in many rounds. I dont know if it was used in any German rounds.

As for your braud asumption that gas can propell a car, so it can blow up an aircraft, thats about the most stupid asumption I have ever seen in this forum.

READ MY POST!!! I said "proper conditions" being "HEAT, COMPRESSION, AND MIXTURE!" and that none of those conditions exist in a wing. If you watch the video I posted, thats the type of combustion you get WITHOUT those types of conditions. Do you see THAT blowing off a wing? Like I said, it didnt even damage a lexan case.

Please, read and thing before posting.

You still havent answered my question as to what proof convinced you that its gas fumes.

M_Gunz
11-30-2009, 06:56 PM
Gee I hope Gibby remembers that he requested me to put him on ignore months ago....
He promised to do the same for me.

TS_Sancho
11-30-2009, 07:03 PM
I said "proper conditions" being "HEAT, COMPRESSION, AND MIXTURE!" and that none of those conditions exist in a wing. If you watch the video I posted, thats the type of combustion you get WITHOUT those types of conditions. Do you see THAT blowing off a wing? Like I said, it didnt even damage a lexan case.

Gibbage, your um...wrong


The 1992 explosion in Guadalajara, Mexico's second largest city, took place on April 22, 1992 in the downtown district of Analco. Numerous gasoline explosions in the sewer system over four hours destroyed 8 kilometers of streets.[1] Gante Street was the most damaged. Officially, 206 people were killed, nearly 500 injured and 15,000 were left homeless. The estimated monetary damage ranges between $300 million and $1 billion.

http://en.wikipedia.org/wiki/1...sions_in_Guadalajara (http://en.wikipedia.org/wiki/1992_explosions_in_Guadalajara)

I believe the families of the 200 dead, 500 wounded and thousands left homeless would question the merit of your claim as well.

BillSwagger
11-30-2009, 07:39 PM
Showing how devastating a fuel explosion is in the sewer of a city doesn't really help explain what we are seeing with the wing offs of the 190s in the footage.
I still have yet to hear how a fuel explosion can occur and not ignite the fuel at the source of the leak. I leak gas from a can and light it from ten feet away, guess what happens?

Maybe we could focus our energies on that point. I don't really see the point in explaining how big a bang fuel can make when we have yet to 'explain' the basics of a fuel fire.

BTW, there is a difference between 'explanation' and 'speculation'.
I think what we are seeing in the footage is perfectly explained by the ammo detonation argument.
You can speculate how fuel gets into the wings, and properly mixes to create the same exact explosion with no fire left at the fuel source. I just don't see that happening here.

I don't think anyone is jumping to conclusions on this either, and if you asked me, the fuel explosion argument is looking like a much further jump than the ammo detonation argument.



Bill

Gibbage1
11-30-2009, 07:47 PM
Originally posted by M_Gunz:
Gee I hope Gibby remembers that he requested me to put him on ignore months ago....
He promised to do the same for me.

I took you off because it seemed you became less of an a-hole. I guess your reverting after the memory of your last vacation woar off. You still didnt answer my question.. Again.

Gibbage1
11-30-2009, 07:50 PM
Originally posted by TS_Sancho:
I believe the families of the 200 dead, 500 wounded and thousands left homeless would question the merit of your claim as well.

Compleatly differant. First, you have an extreamly large volume, and also in a confined space. In the FW-190, we have an extreamly small volume, and in a vented area.

deepo_HP
11-30-2009, 09:06 PM
Originally posted by BillSwagger:
Showing how devastating a fuel explosion is in the sewer of a city doesn't really help explain what we are seeing with the wing offs of the 190s in the footage. neither does a myth-buster video in a garage.


Originally posted by BillSwagger:
I still have yet to hear how a fuel explosion can occur and not ignite the fuel at the source of the leak. I leak gas from a can and light it from ten feet away, guess what happens? l depends very much on where you leaked the can and also, if the can is self-sealing.


Originally posted by BillSwagger:
BTW, there is a difference between 'explanation' and 'speculation'.
I think what we are seeing in the footage is perfectly explained by the ammo detonation argument. yes, there is a difference. i think that all explanations of what i see in the footage are speculative.


Originally posted by BillSwagger:
... and if you asked me, the fuel explosion argument is looking like a much further jump than the ammo detonation argument. no need to ask you, because you said it several times already.

M_Gunz
11-30-2009, 10:26 PM
Originally posted by deepo_HP:
i think that all explanations of what i see in the footage are speculative.

But some people have this idea of one speculation being the only "right" one. To that end all others must be "wrong".

It could have been many things. The spar could have broken just from being shot up. The flashes could easily be
nothing more than incendiary hits. Or an ammo explosion. Or fuel vapor. Let's examine consecutive grainy frames
taken at many per second and decide like we really can and our lives will benefit greatly as a result if we "win".

OTOH we can admit that a guess is only a guess.

JtD
11-30-2009, 10:53 PM
Originally posted by deepo_HP:
stochiometrically, 1kg gasoline burns to 3kg CO2.

i tried a rough calculation on the example of gasoline deflagratiion in otto-engines:

gasoline in combustion engines is injected with 7% (mass) of gasoline.
density of gasoline is 0.78kg/l, density of air is ~1.2kg/l
per liter combustion mix that is 0.08kg gasoline

0.08kg gasoline burn to 240g CO2
density of CO2 is ~2kg/m^3
240g CO2 is 0.12m^3=120l

in this process, 1 liter of fuel vapor results in 120l of CO2.
which is 11,900% expansion of volume.

You made one mistake I found quickly, the density of air is 1.2 kg/m, not per liter, so you'd end up with 11.9% extra volume in your approach.
----
What I did was assuming a stoichiometric combustion as well, with Heptane getting burned completely in air (21% O2, 79 % N2), which looks like that:

C7H16 + 11 O2 + 41 N2 => 7 C02 + 8 H2O + 41 N2

Since all gases have the same number of molecules per volume when under the same conditions, you'd end up with

53 molecules => 56 molecules => 6% extra volume

Now we can also burn a rich mixture, where only the hydrogen reacts completely and the carbon become CO only, again I'm using Heptane in air:

2 C7H16 + 15 O2 + 56 N2 => 14 CO + 16 H2O + 56 N2
73 molecules => 86 molecules => 18% extra volume

And if only the hydrogen was reacting, with single atom carbon gas floating around after the combustion - a worst case scenario- it would look like that:

C7H16 + 4 O2 + 15 N2 => 7 C + 8 H20 + 15 N2
20 molecules => 30 molecules = 50% extra volume

The downside of getting that large extra volume is a slower burn rate, afaik.

Gibbage1
11-30-2009, 11:02 PM
Hay Gunz (and anyone else) you still dodged the same question. What convinced you that its fuel vapor, and not an ammo explosion?

JtD
11-30-2009, 11:07 PM
He's saying it could be this and it could be that. There aren't too many around who say that it must be one sort and cannot be the other.

Gibbage1
11-30-2009, 11:37 PM
Originally posted by JtD:
He's saying it could be this and it could be that. There aren't too many around who say that it must be one sort and cannot be the other.

It could be invisible UFO's. But there is a big difference between improbable, and possible. I think a fuel vapor explosion in the same place happening 6 times is so improbable that it boarders on the impossible. On the other hand, hitting the ammo is very possible. Huge difference.

Also, im not stating it can ONLY be ammo explosion. Im also saying that its possible that the gun powder is causing the smaller explosions, not the shell detonating but I dont see anything else flammable in the wings.

This is what lead me to my conclusion that the most probable cause for the wing detonations is ammo/gun powder.

#1, lack of any other explosive material in the wing other then ammo.

#2, size of explosion bigger then a 20MM

#3, duration of the explosion much longer then any HE shell.

#4, location of the explosion is the same area.

#5, vented ammo and gun bay that prevents a critical buildup of fumes in the area of the explosion.

This is my reasoning. I just want to see other people's reasoning for there theories. So far, all I am getting is "because I think so". Thats why im asking why they are so convinced its fuel vapor, and not ammo.

ImpStarDuece
12-01-2009, 12:53 AM
Originally posted by Gibbage1:
Gunz. Do you read ANYTHING I type, or do you just hit the "reply sarcastically" button every time I post? I asked a question. I didnt make a statement. BTW, it was CORDITE I was thinking of, and it was used in many rounds. I dont know if it was used in any German rounds.



Proper cordite (a straight double base gun cotton and nitro-glycerine mix) hasn't been used since WWI, and even then the British abandoned it fairly quickly for better formulas, about 1915 IIRC. Vaseline or another ingredient were added to add stability and prevent barrel wear.

Triple base low explosives were developed by adding nitroguanidine. This isn't really that closely related to classic pre-WWI cordite, but the name had sort of stuck by then, and it was made in the same places. It was used in some rockets during WWII. The 2" and 3" Unrotated Projectile, again IIRC.

Gibbage1
12-01-2009, 01:06 AM
Thanks for the info. I just remember seeing this a LONG time ago.

http://homepages.solis.co.uk/~autogun/sectHMG.jpg

And somehow associated it with German rounds. The main page only list's this rare 13.9MM as using cordite, and its an anti-tank round. Not something that would be used in aircraft.

Here is the web page BTW. Lots of ammo.

http://homepages.solis.co.uk/~autogun/tankammo.html (http://homepages.solis.co.uk/%7Eautogun/tankammo.html)

deepo_HP
12-01-2009, 04:06 AM
Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by deepo_HP:
stochiobombastically,...
You made one mistake I found quickly, the density of air is 1.2 kg/m, not per liter, so you'd end up with 11.9% extra volume in your approach. </div></BLOCKQUOTE>thx, true that is. i will do another run for it, and hopefully get over your 50%.

that reminds me of some kind of chemical bazaar http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Kurfurst__
12-01-2009, 05:08 AM
Originally posted by Gibbage1:
Also, didnt the German's use RDX in some of there ammo instead of gun powder?

Using RDX as propellant would be extremely stupid, its a very powerful explosive. They did use diglykol on a fairly widespread use though, but thats just another propellant. Originally it was meant as an Ersatz powder, as it was not nitroglycerin-based, but it did have a couple of very useful and advantageous properties (flashless, lower burn temperature -> less barrel wear, higher pressures).

Kettenhunde
12-01-2009, 06:23 AM
6% extra volume


This is why balloon companies make their products out of aluminum.

M_Gunz
12-01-2009, 06:23 AM
Originally posted by JtD:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by deepo_HP:
stochiometrically, 1kg gasoline burns to 3kg CO2.

i tried a rough calculation on the example of gasoline deflagratiion in otto-engines:

gasoline in combustion engines is injected with 7% (mass) of gasoline.
density of gasoline is 0.78kg/l, density of air is ~1.2kg/l
per liter combustion mix that is 0.08kg gasoline

0.08kg gasoline burn to 240g CO2
density of CO2 is ~2kg/m^3
240g CO2 is 0.12m^3=120l

in this process, 1 liter of fuel vapor results in 120l of CO2.
which is 11,900% expansion of volume.

You made one mistake I found quickly, the density of air is 1.2 kg/m, not per liter, so you'd end up with 11.9% extra volume in your approach.
----
What I did was assuming a stoichiometric combustion as well, with Heptane getting burned completely in air (21% O2, 79 % N2), which looks like that:

C7H16 + 11 O2 + 41 N2 => 7 C02 + 8 H2O + 41 N2

Since all gases have the same number of molecules per volume when under the same conditions, you'd end up with

53 molecules => 56 molecules => 6% extra volume

Now we can also burn a rich mixture, where only the hydrogen reacts completely and the carbon become CO only, again I'm using Heptane in air:

2 C7H16 + 15 O2 + 56 N2 => 14 CO + 16 H2O + 56 N2
73 molecules => 86 molecules => 18% extra volume

And if only the hydrogen was reacting, with single atom carbon gas floating around after the combustion - a worst case scenario- it would look like that:

C7H16 + 4 O2 + 15 N2 => 7 C + 8 H20 + 15 N2
20 molecules => 30 molecules = 50% extra volume

The downside of getting that large extra volume is a slower burn rate, afaik. </div></BLOCKQUOTE>

You start off with a cool air and vapor mix and end up with a hot exhaust mix. Apply Boyle's Law to that and?
The expansion drives combustion engines strongly. That should be a clue to anyone not deeply in denial.
1 cup of gas completely burned has the energy of 6 sticks of dynamite, it is not shaken up soda pop!

M_Gunz
12-01-2009, 06:32 AM
Originally posted by Kurfurst__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gibbage1:
Also, didnt the German's use RDX in some of there ammo instead of gun powder?

Using RDX as propellant would be extremely stupid, its a very powerful explosive. They did use diglykol on a fairly widespread use though, but thats just another propellant. Originally it was meant as an Ersatz powder, as it was not nitroglycerin-based, but it did have a couple of very useful and advantageous properties (flashless, lower burn temperature -> less barrel wear, higher pressures). </div></BLOCKQUOTE>

I had to laugh as the other quote looked like he was saying gunpowder in the shell. IIRC that was actually done prior
to about 1880 with bomb mortars and rockets at least. It ended before WWI AFAIK with the use of high explosives.

Now I laugh even harder if it was supposed to some times be RDX as propellant. This comedy just gets better and better!
What new internet discoveries await to be turned into "must be respected Leet-Fackets"? Oooohhhh! It Roxxors!

Xiola
12-01-2009, 06:36 AM
Common sense says its the ammo box exploding guys. Its in exactly the right location for the outer cannon box which often carried mk108 rounds.

Xiola
12-01-2009, 06:37 AM
Lol, how did I get logged in on that secondary account? http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

Kettenhunde
12-01-2009, 06:40 AM
Common sense says its the ammo box exploding guys. Its in exactly the right location for the outer cannon box which often carried mk108 rounds.


The films I have seen the break is between the oleo mount and the gear motor in the wheel well, not the ammo box.

11 post's huh?

Kettenhunde
12-01-2009, 06:43 AM
Lol, how did I get logged in on that secondary account?


Easier to back up your point of view and create the illusion of more participants in the thread?

That is most common reason for alternate identities. The other is if your banned on a consistent basis.

Kurfurst__
12-01-2009, 07:02 AM
Originally posted by Xiola:
Common sense says its the ammo box exploding guys. Its in exactly the right location for the outer cannon box which often carried mk108 rounds.

This seems to me the most likely reason as well. OTOH, the whole discussion is overblown...

Kettenhunde
12-01-2009, 07:21 AM
OTOH, the whole discussion is overblown...


It is very entertaining. It definitely has some very funny moments and I love seeing all the sweeping conclusions people come too based on a few films.

In a 95% confidence level, to get the same chance as flipping a coin of making the right conclusion.....


http://img23.imageshack.us/img23/9715/dumbfq.jpg (http://img23.imageshack.us/i/dumbfq.jpg/)



http://www.stat.auckland.ac.nz...c/Ch08.psampsize.pdf (http://www.stat.auckland.ac.nz/%7Ewild/ChanceEnc/Ch08.psampsize.pdf)

JtD
12-01-2009, 08:44 AM
Originally posted by M_Gunz:

You start off with a cool air and vapor mix and end up with a hot exhaust mix. Apply Boyle's Law to that and?

Yes, I was coming to this. I'll stick with the Heptane and a stoichiometric combustion (plus N2 for the air). If you think I made significants mistakes in the following estimate, feel free to point them out, it's been a while since I last did that.

Burning 1 mol of Heptane produces about 4600000 J of energy. This is what you have to heat up the explosive gases, which are the H2O, CO2 and N2.
They need about
H2O: 44.0 J/(mol*K)
CO2: 54.4 J/(mol*K)
N2: 33.3 J/(mol*K)
average in the range between 0 and 2000C in an isobaric heating process.
Now we have
8 mol H2O
7 mol CO2
41 mol N2
All in all, you'll need 44*8+54.4*7+33.3*41=2098 J to heat up the results of the chemical reaction by 1 K.
Eventually, you can heat it up by 4600000 / 2098 = 2192 K.

Assuming the participants initially were at 0C, you'll end up with a temperature which is (273+2192)/273 = 9.0 times as high as the initial (or final) temperature.

Since p*V = m*R*T and p, m and R being approximately constant, you'll end up with 9.0 times the cold volume.

Eventually, for the stoichiometric combustion of Heptane in air, the volume of the explosive cloud would be around 1.06*9.0=9.5 times the initial volume of the fuel vapour mix.

JtD
12-01-2009, 08:51 AM
The expansion drives combustion engines strongly. That should be a clue to anyone not deeply in denial.
1 cup of gas completely burned has the energy of 6 sticks of dynamite, it is not shaken up soda pop!

Car engines also compress the air before the combustion, gives them a bigger bang.
Do not mistake the volume of the cloud with the power of the explosion, volume of the cloud is just static, something from after the event, the explosion itself is very dynamic.

Gibbage1
12-01-2009, 11:47 AM
Originally posted by Kurfurst__:
This seems to me the most likely reason as well. OTOH, the whole discussion is overblown...

Wow. Kurfy agreed with me on something? http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

I still havent seen anyone post why they think its something other then ammo explosion......

BTW, lets get past the RDX/Cordite. I should know to shut my trap when it comes to ammo propellants. Lets just say its a safe assumption that its normal gun powder. Does anyone think that alone could cause the explosion explosion we see? A single .50 cal going through the casings would rip open a lot of them.

BillSwagger
12-01-2009, 12:03 PM
Originally posted by Kettenhunde:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">OTOH, the whole discussion is overblown...


It is very entertaining. It definitely has some very funny moments and I love seeing all the sweeping conclusions people come too based on a few films.

In a 95% confidence level, to get the same chance as flipping a coin of making the right conclusion.....

</div></BLOCKQUOTE>

I dont think its a matter of making the correct conclusion so much as discovering the facts that might make what happened in the film possible.

It can get overblown when much of the discussion is rooted in distorting the creditability of the poster or his proof, rather than introducing new facts or anything legitimate to back up a counter argument or alternative explanation. It seems to be overblown because nothing is as easily backed as the ammo detonation argument with out having to make further leaps in speculation.

We speak of fuel explosion in the wing:
we must answer how the fuel got there and how it ignites. I think this has been thoroughly explained, however there are still a few holes in the theory which leads me to ask why there is no other fire at the fuel source. Even with sealed tanks, there would still be fuel between the leak and the ignition point. Would we not see more fire in a fuel explosion?

We speak of ammo detonation:
We must answer how a bullet can cause a shell to explode. I think this had been thoroughly explained. It also gives a better case as to why the explosion is more localized specifically at the portion the wing where the ammo happens to be.

horseback
12-01-2009, 03:09 PM
Gibbage wrote:

Wow. Kurfy agreed with me on something? Somewhere, a pig is spreading its wings and taking flight.

cheers

horseback

Kettenhunde
12-02-2009, 08:18 AM
I dont think its a matter of making the correct conclusion so much as discovering the facts that might make what happened in the film possible.

What "correct conclusion" are you going to make, Bill?

Face it son, it is a dumb conversation and there is no "correct conclusion" to be made.

I pointed this out in my very first post in the thread...CSI:IL2!!

The only thing you can discuss is what people "think, feel, wish, want, pray for, or hope".

I have been very amused that it has gone on this long, thank you all for that!

JtD
12-02-2009, 09:21 AM
It appears that my estimate is about ok...

The Fw central wing section, as destroyed in the guncam footage, can contain about .5m of fuel vapours, max.

Rounding up to an expansion factor of 10, this means a steam cloud of about 5m after the explosion, which is a ball with a bit more than 2m in diameter, which is a bit more than the chord of the Fw's wing.

As you can see in the image below, the steam cloud is far larger than that, a very conservative estimate being a diameter of 4m, which means this cloud has about 10 times the volume a small fuel vapour pocket in the wing could produce.

Which, in my eyes, is another definite argument that this explosion does not show a fuel vapour explosion.

http://mitglied.lycos.de/jaytdee/snapshot2.JPG

yuuppers
12-02-2009, 10:17 AM
If the .50" could not detonate the wing ammo in the 190, then how did the .50" detonate train wagons loaded with ammo?

Every time the outer guns had to loaded with ammo, a large hatch dropped down, which would certainly ventilate the the gun bay of any fuel vapour. The Mk108 had a larger shell ejection opening than the MG151/20 > more ventilation, never mind the the fumes from the burned propellant that would fill the gun bay.

BillSwagger
12-02-2009, 10:54 AM
Originally posted by Kettenhunde:
What "correct conclusion" are you going to make, Bill? In the context of that sentence, i simply meant there is no wrong answer, but perhaps in the discussion we can explore possibilities.


Face it son, it is a dumb conversation and there is no "correct conclusion" to be made.

I pointed this out in my very first post in the thread...CSI:IL2!!
I have been very amused that it has gone on this long, thank you all for that!

I am equally entertained by the discussion but for different reason, i think some valid points have been made and i've learned a bit more about the 190 as well as the some the explosives involved in the German ammo.



The only thing you can discuss is what people "think, feel, wish, want, pray for, or hope".
This might be true, but that shouldn't discount any thoughts that raise valid questions or point to relevant facts.
How far in life do you think i could get not taking into consideration what other people "think, feel, wish, want, pray for, or hope".
I think its easier to dismiss it as a joke, but I'm surprised someone who has a decent understanding of aviation wouldn't want to participate in the discussion more seriously. Maybe you are at your wits end, but I'm starting to think you are just biased Crump.



Bill



Face it son...
Who are you, my dad? http://forums.ubi.com/images/smilies/partyhat.gif

Gibbage1
12-02-2009, 12:16 PM
I think we have extruded the last bit of viable information out of this topic. So far there is a lot of supporting evedence that the most likely explination for the FW-190 wing detonation is ammo explosion or propellant ignition. So far I havent seen any sort of convincing evedence supporting the fuel fume therie. Unless they bring something new (and relitive) to the table, I dont see any reason to contenue.

BaronUnderpants
12-02-2009, 01:54 PM
So, Fw190 beeing hit by 20mm cannon fire is of the table?


Ok, just checking.


To even begin to draw conclusions someone with the only possible "right" awnser should find out where the photage comes from. Kind of important me thinks.

Until then, keep on guessing, i dont mind.

Gibbage1
12-02-2009, 02:04 PM
Originally posted by BaronUnderpants:
So, Fw190 beeing hit by 20mm cannon fire is of the table?


Yes, unless you can prove that a 20MM has a 4M fireball that last's for seconds. I already showed film of real 20MM explosions that only last for 1-2 frame and are not nearly the size.

Also, im just saying that ammo explosion is the most prabable explination, not the only one. And its based on the listed facts.

#1, size

#2, duration

#3, location

Your free to bring any new evedence.

BaronUnderpants
12-02-2009, 02:07 PM
Originally posted by Gibbage1:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by BaronUnderpants:
So, Fw190 beeing hit by 20mm cannon fire is of the table?


Yes, unless you can prove that a 20MM has a 4M fireball that last's for seconds. I already showed film of real 20MM explosions that only last for 1-2 frame and are not nearly the size. </div></BLOCKQUOTE>


Me, prove, why?


As far as calling conclusions drawn from a 70 year old overexpose/underexposed, grainy clip proof/facts is pretty far feched (putting it nicely)imo.

Good theory though, not dissegreeing, or agreeing for that matter http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Gibbage1
12-02-2009, 02:12 PM
Again, your putting words into my mouth. Im not concluding anything. Im just saying that the most possible explination is an ammo explosion based on the listed facts.

#1, size

#2, duration

#3, location

The only plausable therie available that fits all 3 is ammo explosion.

Can you think of a therie that fits all 3 facts?

RegRag1977
12-02-2009, 02:23 PM
Repeat something a thousand times and it becomes the truth?

Let's see if it works with this thread. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

BaronUnderpants
12-02-2009, 02:23 PM
Originally posted by Gibbage1:
Again, your putting words into my mouth. Im not concluding anything. Im just saying that the most possible explination is an ammo explosion based on the listed facts.

#1, size

#2, duration

#3, location

The only plausable therie available that fits all 3 is ammo explosion.

Can you think of a therie that fits all 3 facts?


I understand what you are saying, i do.

My point is, one can not draw any conclusions what so ever based on those clips.

Any conclusions made from "facts" drawn from said clips are inherrently wrong, no matter what anyone says.

I mean, we havent even established WHERE those clips comes from, we dont even know that basic info, what is hitting the FW??

For ex, u can not estimate the sice of a fire ball from a 70 year old overexposed frame, u simply can not do that. 50% of that fireball could just as easily be overexposure, theres no way of telling.

I understand why u think its ammo explosion, i can think its 20mm hits without having to prove anything since i cant anymore than u can.

Apart from learning new stuff about explosives, Fw ammo layout and so on, all the guesses are as right on page 50 as they where on page 1 no matter how many charts we post.


As it stands now, going by what have been sugested what could be happening (Fuel vapor, ammo explosion, 20mm hits) there is a 33.33333% chanse of it beeing a ammo cook of.


As said before, im not dissegreeing with u.

BaronUnderpants
12-02-2009, 02:25 PM
For ex: How many gallons of fuel or/and kg of explosives is involved here.


http://i217.photobucket.com/albums/cc79/Maax1000/40mm1-1.jpg


http://i217.photobucket.com/albums/cc79/Maax1000/40mm-1.jpg
There is 100% more info on theese pics than those old clips (colour)

M_Gunz
12-02-2009, 02:29 PM
Originally posted by JtD:
It appears that my estimate is about ok...

The Fw central wing section, as destroyed in the guncam footage, can contain about .5m of fuel vapours, max.

Rounding up to an expansion factor of 10, this means a steam cloud of about 5m after the explosion, which is a ball with a bit more than 2m in diameter, which is a bit more than the chord of the Fw's wing.

As you can see in the image below, the steam cloud is far larger than that, a very conservative estimate being a diameter of 4m, which means this cloud has about 10 times the volume a small fuel vapour pocket in the wing could produce.

Which, in my eyes, is another definite argument that this explosion does not show a fuel vapour explosion.

http://mitglied.lycos.de/jaytdee/snapshot2.JPG

But it is consistent with ammo explosion? One that would only break the wing?
And since you have no other explanation that must be what the picture shows?
Nothing burns inside and vapors would limit themselves to inside the wing?

I keep saying -- you don't have enough information to determine what is going on outside the very limited.
It is like thinking that to drive only the steering wheel is important from seeing only the steering wheel
being used in a movie and pictures of a car. You only include/exclude what you know and invent for yourselves.
It is like basing what fighter is the best upon minute examination of a few charts and disregarding all else.

Gibbage1
12-02-2009, 03:08 PM
Originally posted by BaronUnderpants:
I understand what you are saying, i do.

My point is, one can not draw any conclusions what so ever based on those clips.


Again, conclusion. Im only saying that the most likely reason for the wingoff's is ammo. Thats not a conclusion, but a therie. BIG differance. A conclusion is "The ONLY reason", and im not saying that.



Any conclusions made from "facts" drawn from said clips are inherrently wrong, no matter what anyone says.

I mean, we havent even established WHERE those clips comes from, we dont even know that basic info, what is hitting the FW??


The biggest possible round that can be hitting that is 20MM. Even if we are to assume its ALL 20MM, that does not explain the size of the 3 facts I listed.



For ex, u can not estimate the sice of a fire ball from a 70 year old overexposed frame, u simply can not do that. 50% of that fireball could just as easily be overexposure, theres no way of telling.


Over exposure on all 6 samples? Thats a bigger assumption then saying its just ammo. Also, that does not explain the other 2 facts away. Duration (even overexposure would not create a fireball lasting more then a few frames) and location.



I understand why u think its ammo explosion, i can think its 20mm hits without having to prove anything since i cant anymore than u can.


Have you seen 20MM hits? I posted 2 video's showing them clearly (both in grainy WWII video, and in modern video) and they look NOTHING like what we see on the FW video's. So why is it your "I feel it is" is better then "Based on these facts"? Im not discrediting your feelings. I just want to know what they are based on.



As it stands now, going by what have been sugested what could be happening (Fuel vapor, ammo explosion, 20mm hits) there is a 33.33333% chanse of it beeing a ammo cook of.


Your math is a bit off I think.

I have been asking for the last 5+ pages WHY, WHY WHY WHY WHY WHY do you think it could be fuel vapor? What do you base this "feeling" on? So far, NOBODY has replied. Not a single poster has yet to step up to the plate and explain why. Leading me to think that its because its like you said, they only have there "feelings" to back it up. The therie that its ammo is based on a LOT more then "feelings".

Kettenhunde
12-02-2009, 03:55 PM
So far, NOBODY has replied. Not a single poster has yet to step up to the plate and explain why.

Funniest thing I have read all night!

http://forums.ubi.com/images/smilies/partyhat.gif