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View Full Version : Spitfires with Drop Tanks Exploding on Takeoff



SlickStick
08-30-2005, 09:18 PM
I recently started using drop tanks and noticed that if you slightly dip a wing on take-off, not even touching the ground, you explode like you have a bombload. I know for sure the Mk. VIII and Mk. IXe have this, but the Mk IXc and Mk. VIII (CW) did not do it.

Here is the Mk. IXe. Now, granted, one would try NOT to dip one's wing on take-off, but it happens and if you catch it before the wing touches, should you blow-up? The screen is actually after, so the wing tip was a bit higher even.

http://img364.imageshack.us/img364/655/mkixeexplode7ol.jpg

Here is the Mk. IXc, where I'm dragging the wing on the ground on take-off.

//img279.imageshack.us/img279/8157/mkixcwingdrag8aw.jpg

I made several tracks of the IXc, IXe and VIII, but anyone can repeat the test. I also tried 45 and 90GAL tanks. I put a 500 + 2 - 250lb bomb load on the Mk IXe and it exploded like the drop tank loadout.

I figured I'd try another plane and the La7 drags the wing as well.

http://img383.imageshack.us/img383/3550/la7wingdrag2gy.jpg

This can be avoided with a clean, correct take-off, but everybody makes a mistake once in awhile and sometimes you need to get off of the ground in a hurry and may dip a wing slightly because you are at a slower take-off speed.

If you're in certain Spitfires and possibly other models in other plane series I'll bet, you're penalized further than other planes in the sim that can drag a wing with no explosion.

FritzGryphon
08-30-2005, 10:54 PM
I've found the same in the past with I-16 and bombs.

This one is weird of course, because the drop tank never actually touches the ground.

Edit: I-16 droptanks have the same problem. When you touch the wingtip to the ground (and not the tanks), you explode.

p1ngu666
08-31-2005, 02:37 AM
how odd http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

Dew-Claw
08-31-2005, 03:08 AM
When the wing touches the ground it completes a circuit forcing an electrical spark that detonates the tank.



I have no idea what I'm talking about, but it sounds good.

VW-IceFire
08-31-2005, 06:53 AM
Originally posted by Dew-Claw:
When the wing touches the ground it completes a circuit forcing an electrical spark that detonates the tank.



I have no idea what I'm talking about, but it sounds good.
Thats just a bad flux capacitor install http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

MEGILE
08-31-2005, 06:53 AM
Originally posted by Dew-Claw:
When the wing touches the ground it completes a circuit forcing an electrical spark that detonates the tank.


And as we know, delta wood may be resistant to MK-108s, but it sure doesn't conduct electricity http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

MEGILE
08-31-2005, 07:02 AM
Its a weird bug for sure... I've done this lots of times in the past on dogfight servers... taking 25% fuel and a 90gl drop tank.
I just always put it down to hitting a clump of Oleg's Grass(tm).

SlickStick
08-31-2005, 09:41 AM
At first, I thought I was just being careless and touching my wing down with the Mk. VIII and the Mk IXe. Then, after viewing tracks, I realized the wing is nowhere near touching when you explode.

Even stranger that the Mk. IXc can do circles on it's wing tip with the same drop tank installed and not explode. http://forums.ubi.com/images/smilies/blink.gif

tigertalon
08-31-2005, 06:00 PM
Are you sure there wasn't a Fw190 vulching you from your 3? They have a bad habit of blowing stuf up, lol.

Odd bug indeed. I wonder how many and which planes are affected...

SlickStick
08-31-2005, 07:34 PM
There was a time, I forget if it was during IL-2 or FB, but after a patch we had issues with planes exploding if they dipped a wing. At that time, I seem to recall it affected all planes.

As near as I can tell, the explosion is exactly what would happen with bomb loadout and you dipped the wing. I wish I had time to do more testing. Not only on this, but the gun sync issue as well for more planes.

p1ngu666
08-31-2005, 07:48 PM
meg, u should probably take 30 or 45gal droptank instead of 90 http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

SlickStick
08-31-2005, 08:11 PM
Originally posted by p1ngu666:
meg, u should probably take 30 or 45gal droptank instead of 90 http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

I tried, but they cause explosions, too. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

FritzGryphon
08-31-2005, 08:14 PM
Why use a tank at all?

You know, the drop tank just empties into the main tank at mission start, if you don't have full fuel. It gives no advantage to lug an empty DT around.

_VR_ScorpionWorm
08-31-2005, 09:28 PM
Hey, mine never says Bombload: Detonated......

SlickStick
09-01-2005, 08:02 AM
Originally posted by _VR_ScorpionWorm:
Hey, mine never says Bombload: Detonated......

It should. Make a quick track of the next take-off explosion and play it back in 1/4 speed, using the pause key near the point in the track the explosion is about to happen, and you'll catch it on the screen before more text comes.

Kuna15
09-01-2005, 03:17 PM
I happen to be rookie at the issue, but are bombs going to blow every time if we ditch with them under wings?

Someone mentioned some kind of arming mechanism (small propeller in bomb nose that rotates and when it reaches end bomb is armed or something like that).

SlickStick
09-01-2005, 03:46 PM
Originally posted by FritzGryphon:
Why use a tank at all?

You know, the drop tank just empties into the main tank at mission start, if you don't have full fuel. It gives no advantage to lug an empty DT around.

Are you saying this is how the game code works? Because in RL, I wouldn't expect an interconnection between the internal and external tanks, other than the fuel lines feeding a switch, that would allow the engine to feed from either source?

I'm not exactly sure how drop tanks worked in RL, but I would expect that there was a switch to go between internal and external tanks.

Having a direct interconnect between internal and external tanks doesn't seem right to me, especially since you jettison the external tank when it's empty.

Where would I be able to learn how drop tanks worked in WWII?

I was under the impression, I could take 25% fuel, use the drop tank for take-off and cruising over to fight, jettison and still have 25% fuel left for the fighting and return trip. A nifty tip all good dogfighters use in this game, but if it works as you say, then there is no point.

Tonight I'll spawn a Mk VIII with 25% and check fuel gauge. Then, with 90GAL drop tank and 25% and check fuel gauge. If what you say is true, I should see more fuel upon spawn with 90gal tank, right?

SlickStick
09-01-2005, 03:51 PM
Originally posted by Kuna15:
I happen to be rookie at the issue, but are bombs going to blow every time if we ditch with them under wings?

Someone mentioned some kind of arming mechanism (small propeller in bomb nose that rotates and when it reaches end bomb is armed or something like that).

Yes, in real life, there was a little prop that rotated as the bomb fell and was connected to the fuse of the bomb (Pardon my bad terminology). When the bomb fell a certain distance the arming mechanism rotated far enough out to arm the bomb (this is the part that made the whistling sound as a bomb was dropped). In game, this is simulated with the bomb delay in the Arming screen in seconds.

I'm not sure about all planes anymore, but in many, if you touch a wingtip down with a bomb load, you explode. Others, may let you. This stems back to an old issue of planes blowing up on runways with bomb loadouts in a past version of the game. It was fixed back then. A good rule of thumb is to jettison armament before ditching. We don't have that command, only to jettison drop tanks, so just release bombs or fire rockets at a safe distance before ditching. (I say a safe distance, because you don't want to be blown up by your own falling bombs while ditching. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif)

I'm not sure what's happening with the Spitfires now though and why a drop tank that doesn't touch the ground explodes like a bomb load that's been detonated. http://forums.ubi.com/images/smilies/blink.gif

Willey
09-01-2005, 04:22 PM
Originally posted by FritzGryphon:
Why use a tank at all?

You know, the drop tank just empties into the main tank at mission start, if you don't have full fuel. It gives no advantage to lug an empty DT around.

It was like that once. But it's not anymore. I took some DTs in 4.01 already and it didn't change my fuel gauge. Try it with 109/25%. It's at 100l then. In some older versions it would jump up to 400l right at the start, just what you described.

SlickStick
09-06-2005, 09:14 AM
Thanks for the updated info, Willey. http://forums.ubi.com/images/smilies/25.gif

SlickStick
09-06-2005, 09:16 AM
I meant to do more testing with other planes for my email to 1C, but my "Honey Do" list was longer than my arm and flying time was severely hampered this weekend. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

p1ngu666
09-06-2005, 01:12 PM
it depends on the plane, the allied stuff feeds from the droptank directly, while the 109 the fuel is pumped upto the main tank, and the engine is fed from the main tank always

SlickStick
09-06-2005, 02:48 PM
Thanks, p1ngu666. However, I did not test in 109 and what you wrote conflicts with what Willey wrote a page back about the current 109s in-game.

I'll have to test where the fuel goes on spawn in a 109, to see for myself now. Thanks allot! http://forums.ubi.com/images/smilies/16x16_smiley-mad.gif http://forums.ubi.com/images/smilies/16x16_smiley-tongue.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

justflyin
06-21-2006, 09:28 AM
Glad I searched for this topic first. Much to my surprise, I blew up on take-off several times over the weekend and couldn't, for the life of me, figure out why.

This explains it and this bug still exists in V4.04m. It would be good if someone could test this in V4.05m. It also happens with the +25lb Spitfire.

Daiichidoku
06-21-2006, 03:12 PM
Originally posted by justflyin:
It also happens with the +25lb Spitfire.

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

jvmasset
06-21-2006, 04:00 PM
Hello everyone!

Considering everything having been said in this thread I suspect very much that the "exploding on takeoff" problem is not really a bug but rather an unfortunate effect of the still relatively crude damage model. The damage to the aircraft is identified when "something" intersects whith one of the hitboxes covering the airplane. These hitboxes are just that, rectangular boxes of various sizes and elongations.
I do not know how many of them cover a Spitfire wing, but I would say 1 or 2: these "envelop" the wing...So I suppose it does not take a lot of dipping on takeoff to have the hitbox hitting the ground largely before the wing (you may remember the Mosquito wrongly placed hitbox over the wing on its first release...weird effect!).
I suppose also there is a simple relationship between the aircraft ordnance/load and the severity of the consequences...
The truth is that the DM in IL2FB/PF is still too simple! I just hope that the DM in BoB will be made out of many more hitboxes, including sub-boxes for ammo boxes, ordnance or tanks.
I suppose that the principle of hitboxes will be kept because it is a lot simpler to compute the intersection of a bullet trajectory with a flat surface than with a complex 3D model. But if the number of hitboxes is high enough, it will be difficult to notice a difference. The rest is a matter of localizing and defining the representation of the damage, and its short/middle-term consequences on the aircraft airworthiness...
Until then I think we will have to live with horizontal wing takeoffs for a while...

JVM

justflyin
06-22-2006, 08:11 AM
Originally posted by jvmasset:
Hello everyone!

Considering everything having been said in this thread I suspect very much that the "exploding on takeoff" problem is not really a bug but rather an unfortunate effect of the still relatively crude damage model. The damage to the aircraft is identified when "something" intersects whith one of the hitboxes covering the airplane. These hitboxes are just that, rectangular boxes of various sizes and elongations.
I do not know how many of them cover a Spitfire wing, but I would say 1 or 2: these "envelop" the wing...So I suppose it does not take a lot of dipping on takeoff to have the hitbox hitting the ground largely before the wing (you may remember the Mosquito wrongly placed hitbox over the wing on its first release...weird effect!).
I suppose also there is a simple relationship between the aircraft ordnance/load and the severity of the consequences...
The truth is that the DM in IL2FB/PF is still too simple! I just hope that the DM in BoB will be made out of many more hitboxes, including sub-boxes for ammo boxes, ordnance or tanks.
I suppose that the principle of hitboxes will be kept because it is a lot simpler to compute the intersection of a bullet trajectory with a flat surface than with a complex 3D model. But if the number of hitboxes is high enough, it will be difficult to notice a difference. The rest is a matter of localizing and defining the representation of the damage, and its short/middle-term consequences on the aircraft airworthiness...
Until then I think we will have to live with horizontal wing takeoffs for a while...

JVM

Hi JVM,

If you study the pictures carefully, you'll notice the Spitfire drop tank is in the center of the plane under the fuselage and never even comes close to touching the ground. Also, the fact that it only happens for the IXe, VIII and +25lb Spitfires, but not the IXc or the VIII (CW). You can literally drag the IXc's wing on the ground around in a circle and nothing happens, but slightly dip your wing on take-off in a IXe with drop tank and you go BOOM!

This is a confirmed bug that used to exist across all planes at one time early in the series. It was patched for most planes, but these Spitfires still have this bug.

It has nothing to do with simplified damage model or hit boxes, as hit boxes in this game are almost exactly sized within each component of the plane. Or at least that's what I've read before around here.

Plus, the other hint is the "Bomb Load Detonated" message in the first screenshot. There are no bombs loaded and drop tanks should NOT explode if they touch the ground EVER. Besides the fact that the drop tank is nowhere near touching.

JG52Karaya-X
06-23-2006, 09:26 AM
I just tried it myself offline loading a random multiplayer map and selecting a Spitfire IX 25lbs with 90gallons belly tank.

First I did some intentional ground-turn with wing contacting the ground. Nothing... the undercarriage broke down on me and the fuel tank was wasted but my plane did not explode. Just sat on its belly.

Then I respawned and took off. Just after catching some air I rolled over to one side and let the wingtip touch the ground. You could see a little line of dust forming where the wing touched down but no damage let alone explosion.

Did the same thing with the SpitIXe, SpitIXc, SpitIX HF... everytime the same result: no explosion

Did you take the same fuel tank each time? Maybe its a bug with one of them - I always took the 90 gallon tank...

justflyin
06-23-2006, 09:44 AM
Originally posted by JG52Karaya-X:
I just tried it myself offline loading a random multiplayer map and selecting a Spitfire IX 25lbs with 90gallons belly tank.

First I did some intentional ground-turn with wing contacting the ground. Nothing... the undercarriage broke down on me and the fuel tank was wasted but my plane did not explode. Just sat on its belly.

Then I respawned and took off. Just after catching some air I rolled over to one side and let the wingtip touch the ground. You could see a little line of dust forming where the wing touched down but no damage let alone explosion.

Did the same thing with the SpitIXe, SpitIXc, SpitIX HF... everytime the same result: no explosion

Did you take the same fuel tank each time? Maybe its a bug with one of them - I always took the 90 gallon tank...

Are you running V4.05m? As I'm still at V4.04m, I asked above for someone to test in V4.05m. Maybe this issue was addressed already. http://forums.ubi.com/images/smilies/25.gif

If you are running V4.05m, then could you also try the Mk. VIII? Also, just one last request, load full bombs on the +25lb and attempt again. I know this is allot to ask, but I'll test further upon getting V4.06. I'm not positive if it only happens when a wheel is still touching the ground either.

BTW, thanks for taking the time to test!!!

JG52Karaya-X
06-23-2006, 10:32 AM
Originally posted by justflyin:
Are you running V4.05m? As I'm still at V4.04m, I asked above for someone to test in V4.05m. Maybe this issue was addressed already. http://forums.ubi.com/images/smilies/25.gif

Yep I'm running 4.05m

If you want I will test the whole Spitfire range again but I predict it will be the same.

JG52Karaya-X
06-23-2006, 10:47 AM
Okay, back again. The whole test took me about 15min and here's the result.

If you happen to have wingcontact while one of your wheels is still down you're going home in a box http://forums.ubi.com/images/smilies/59.gif http://forums.ubi.com/images/smilies/winky.gif

Happens on both Seafire Mk.IIIs, both Spitfire MkVIIIs and all Mk.IXs. However I had to do it on purpose, on a normal takeoff run it shouldn't happen in the first place.

If you have wingcontact without one wheel down you wont suffer anything, same for breaking the undercarriage on the ground while the tank is mounted.

But I agree it is kinda odd and deserves a look at...

justflyin
06-23-2006, 10:54 AM
Thank you very much, Karaya!! The main reason I bring this up is that, every now and then, and I've yet to explain it, ONLY one of my spawns in the same plane will result in what appears to be excessive torque to one side. More than normal and only one out of many spawns.

As I'm rolling down the runway, the wing just starts dipping to the left, more than usual on this one spawn and I go BOOM. Regardless of the strange circumstances, loaded bombs or droptanks on late-war Spitfires should not cause explosions AT ALL.

I could also swear I've read that bombs weren't "live" under the wings and I've read that they were only armed upon release. Some, if not most US Bombs that I've seen used a small-propellored fuse that armed the bomb as it fell, IIRC. Hence, the whistling sound, I believe.

Of course, I'm no armament expert and have no written form of reference at the moment, just my "maybe bad" memory. hehe

Brain32
06-23-2006, 10:59 AM
As I'm rolling down the runway, the wing just starts dipping to the left...
I would be more concerned with that...

justflyin
06-23-2006, 11:10 AM
You're right, Brain. It's almost like the excessive torque is "programmed" to happen randomly. It's always more than usual and the plane always does the same thing during it.

I'll have to start keeping a quick log of the number of spawns and the number of times I "feel" something is happening that is different. It's just strange and seems to happen in Zeros that I fly, too.

Rudder becomes very unresponsive to try and correct it as well during these "strange" times.

crazyivan1970
06-23-2006, 03:32 PM
Ok, i would like to know if anyone sumbitted tracks to pf@1c.ru? Yes? no?

Siwarrior
06-25-2006, 11:21 PM
Originally posted by Dew-Claw:
When the wing touches the ground it completes a circuit forcing an electrical spark that detonates the tank.



I have no idea what I'm talking about, but it sounds good.

lmao http://forums.ubi.com/images/smilies/25.gif thats the way to be http://forums.ubi.com/images/smilies/clap.gif

Stackhouse25th
06-26-2006, 02:06 PM
Quite a few aircraft do this, it is unusual. The ME262 with bombs if you touch the tail. It shouldnt do this.

justflyin
06-27-2006, 01:46 PM
Originally posted by crazyivan1970:
Ok, i would like to know if anyone sumbitted tracks to pf@1c.ru? Yes? no?

I've learned that an email was sent with an explanation and link to this thread, but actual tracks would probably best show this issue, as it is now confirmed to happen when a wheel is still touching and the plane leans to one side. I will make tracks tonight for emailing to 1C. Good suggestion, Ivan. I'll also try the Me-262, Stackhouse, and the I-16 as mentioned earlier in the thread by Fritz.

Now, mind you, a correct take-off is a work-around, but everybody makes mistakes and getting off the ground in a hurry is sometimes a mission priority. Bombs and drop tanks should never explode wjile still on the plane, right? They were not "LIVE" at that point, right?

DKoor
05-26-2008, 06:05 PM
Can't be arsed to check... do Spits still own themselves @ take off with drop tanks?