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View Full Version : The Critical Difference and Spud Guns



jayhall0315
02-05-2009, 01:53 PM
Over the last four months or so, I have switched from being a flier who was about 50 percent open cockpit and 50 percent closed to being a guy who likes either Full Real only or fullswitch with only limited icons. This cuts down tremendously on the amount of rammers, slammers, Spit 25 lbs pilots and head on bandits who try to spray you from 1 km out but I have noticed some funny things. First off is what I call the 'critical difference angle' (since I dont know jack about aerospace engineering except math stuff). I assume that Oleg and his team took detailed photos of the inside of every flyable plane in Il2 and so I must assume IL2 at least gives a pretty close resemblance to the real cockpit (at least in layout). Look at picture one of the Spit MK IX and notice how tiny the distance is between the center of the crosshairs and where the forward nose fuselage blocks the pilot's view.

http://www.xtremesystems.org/forums/attachment.php?attachmentid=94213&stc=1&d=1233865330]http://www.xtremesystems.org/f...3&stc=1&d=1233865330

Now look at picture 2 and notice with the Corsair that the distance is larger.

http://www.xtremesystems.org/forums/attachment.php?attachmentid=94214&stc=1&d=1233865330]http://www.xtremesystems.org/f...4&stc=1&d=1233865330

Is this not critically important for higher target accuracy ? I am no frigging supra-genius, but if I were a WWII aircraft designer, wouldn't I want to make this distance (angle) as large as possible ? This would allow the pilot to see under the crosshairs as well, instead of only above them as with some airframes, would it not ? One reason I enjoy the Corsair so much in IL2 is because of this large angle which allows me to see under the crosshairs and still keep the bandit in view if he rolls tight or dives away below me. With crosshairs like those on the Spit, a bandit can roll tight and dive away below me and it takes me that extra 1/3 of a second to realize that since the nose fuselage was blocking my view. Wouldn't this have been an easy fix to do in WWII.... simply remount the guns in the wing on a wedge and reposition convergence so that the bullet streams met slightly higher and then recalibrate the HUD ? Seems to me I could easily get an IL2 flier to go from 4% hit rate to 8% with a simple adjustment of this angle ? Any of you IL2 historians care to add more details ?

Also, in my almost 10 months of flying now, I have come to wonder why IL2 would even allow the game engine to have open cockpits and external views? Why is closed cockpit with no external views only for the upper intermediate to advanced players ? To me, it seems simple – There were no 'open' cockpits in WWII, so if I am a developer I would never put that option in my game...period. As far as I know, there were no secret flying drones to provide WWII pilots with 'external' views either, so why include them in the game in the first place? I can understand external views being allowed on an Ntrk file so that you can critique your own performance from all angles but during flying..... why ? I can even understand the need for icons since human visual acuity in real life was more precise than trying to discern pixel dots on a 1900x1200 pixel monitor, but open cockpits and external views dont seem right to me. Does this tradition come from some earlier flight sim and Oleg felt he had to include it too or sales would be low ?

Finally, I realize the limitations of what WWII developers had to work with in some regards but why not use a rear firing improved shrapnel grenade to deter guys on your six. In the range of 300 – 700 kph with a critical distance of say 500 meters, with the right explosive and timing, I would think a decent engineer would have developed a rearward firing spud gun where the spud is highly explosive grenade type device that sends shrapnel in a rear ward facing (away from the firing plane and towards the chasing plane) manner with the goal being of shredding the other guys radial engine or forward wing areas. So lets say I am a Me 262 and I am vulnerable down low when I take off and land, and I have to slow up to 300 kph as I make my approach and a P51 comes down on my and begins to close on my six. As he gets to the 500 meter mark, I fire my fart gun and send the explosive grenade directly at him, which then goes off 100 m if front of him sending high speed shrapnel right at his water cooled engine. What do you guys think ? Sounds like it would be a doable engineering problem to me and yet (unless mistaken and that is likely) I have never heard of this.

Be interested to see what some of you IL2 master historians have to say - Jay

squareusr
02-05-2009, 02:27 PM
Keep in mind that in real life, the center of the crosshair is not fixed to the center of the projection mirror but can be anywhere on that glass rectangle, depending on head position.

But sure, visibility is as much an important difference between the various types as armament, speed, or readability of the gauges.

Angling the guns off the centerline would be very bad though, because it would be like shooting with a strong side wind. It's difficult enough to aim with the little sideslip and different alpha angles at different speeds with guns that are centered forward as good as possible.


To me, it seems simple – There were no 'open' cockpits in WWII, so if I am a developer I would never put that option in my game...period. would you remove the refly button on basis of the same argument as well?

imagine somone who just bought his first flight sim to be forced to taxi and start with a taildragger, seeing only instruments, sky and a glimpse of that huge engine...

About the "fart gun": aiming to the rear is damn difficult, and a timed grenade can only help a little. Just look at the effect heavy artillery has on you, it can remove your wings with one blast, but if it detonates 20 m away it has less effect than handgun caliber fired at 500 m - and those shells are huge: how much forward firepower would you be willing to sacrifice to balance against a few shots for the "fart gun"? (not even counting the gun itself)

But your speculations remind me of a line of thinking that comes to me from time to time as well: how would we, with 60 years of retrospective pondering, modern manufacturing technology and computer aided engineering, design a fighter that followed the (well, kind of arbitrary) rules of "no jets, no A2A missiles, no on-board computers"?

jayhall0315
02-05-2009, 02:40 PM
.....Angling the guns off the centerline would be very bad though, because it would be like shooting with a strong side wind. It's difficult enough to aim with the little sideslip and different alpha angles at different speeds with guns that are centered forward as good as possible.

would you remove the refly button on basis of the same argument as well? ....



I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely. This would allow the pilot to have more room to see under the crosshairs (in effect, making the closed cockpit experience ever so slightly more like the open cockpit experience). My question was also meant for real life as well and not just IL2 ? Would not a simple fix like this have improved accuracy in any Air Force that used it in WWII ?

Would I remove the refly button ?.... ummm... good question. My answer would probably be no, but I would be in favor of a new type of server style that is almost identical to the current coop mode where once you get shot down, you stay down until the last guy flying dies or lands. This would totally eliminate 98% of the ramming, slamming, head ons and crap like that, even for open cockpit servers. It would mean that you would have to value your 'virtual' life more and thus folks would begin to fly more realistically.

Bobbo_Tabor
02-05-2009, 03:07 PM
I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely. This would allow the pilot to have more room to see under the crosshairs (in effect, making the closed cockpit experience ever so slightly more like the open cockpit experience). My question was also meant for real life as well and not just IL2 ? Would not a simple fix like this have improved accuracy in any Air Force that used it in WWII ?

The designers of the Spitfire were looking for as much streamlining as possible to get the most speed out of the plane and the designers of the Corsair were looking as much visibility possible so the pilot see around that huge engine and actually land the thing on a carrier. There were an incredible number of considerations that when into the plane design and typically they didn’t have much time to perfect things.


Would I remove the refly button ?.... ummm... good question. My answer would probably be no, but I would be in favor of a new type of server style that is almost identical to the current coop mode where once you get shot down, you stay down until the last guy flying dies or lands. This would totally eliminate 98% of the ramming, slamming, head ons and crap like that, even for open cockpit servers. It would mean that you would have to value your 'virtual' life more and thus folks would begin to fly more realistically.

Meh, I’ve personally rammed enough planes being to eager for that shot but what else do you expect from early war Soviet pilots?

Ba5tard5word
02-05-2009, 03:09 PM
The Corsair's wings/guns are lower (I guess) and the cockpit is higher on a large fuselage.

WTE_Galway
02-05-2009, 03:11 PM
Originally posted by jayhall0315:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
.....Angling the guns off the centerline would be very bad though, because it would be like shooting with a strong side wind. It's difficult enough to aim with the little sideslip and different alpha angles at different speeds with guns that are centered forward as good as possible.

would you remove the refly button on basis of the same argument as well? ....



I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely. This would allow the pilot to have more room to see under the crosshairs (in effect, making the closed cockpit experience ever so slightly more like the open cockpit experience). My question was also meant for real life as well and not just IL2 ? Would not a simple fix like this have improved accuracy in any Air Force that used it in WWII ?
</div></BLOCKQUOTE>

Actually historically most Corsair pilots sat low in the cockpit out of harms way and aimed with tracer http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Seems to me the only effective way of achieving what you want would be to move both seat position and gunsight upwards 3 or 4 inches.

Sooo ... in real life what would you prefer -

a) Sitting low in the cockpit with the corresponding problems with deflection shots.

OR

b) Perched up really high so your head becomes a super target with no armor but you get a nice view through the aiming reticule.

WTE_Galway
02-05-2009, 03:18 PM
Originally posted by squareusr:
About the "fart gun": aiming to the rear is damn difficult, and a timed grenade can only help a little. Just look at the effect heavy artillery has on you, it can remove your wings with one blast, but if it detonates 20 m away it has less effect than handgun caliber fired at 500 m - and those shells are huge: how much forward firepower would you be willing to sacrifice to balance against a few shots for the "fart gun"? (not even counting the gun itself)



Actually by mid war the US (and I believe also the japanese)had developed proximity fused AAA which detonated when the shell past close to an aircraft.

So in theory you could have used the same technique to proximity fuse ordinance dropped behind a plane ... you would want to make sure it didn't pickle until well after you dropped it and be damn careful your wingman wasnt close behind you.

Aaron_GT
02-05-2009, 03:26 PM
I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely.

This was tried on a number of planes - the Gloster design to the same spec as the Whirlwind, the Pz.11 and proposed for RAF fighters in the early 1930s. Turned out it made things harder to hit in the end.

In terms of the sight angle it was an issue, but making the hood taller added drag and would mean a slower plane so less chance of beingin guns range. In the F4U the bigger angle was due to a higher seat position being required to make landing visibility better because the cockpit was moved back to make room for the fuel that was moved from the wings to make room for more guns, so it was pretty accidental!

In the Spitfire a periscope was tested to improve angle but was impractical. The Malcolm hood allowed a slightly higher seat position than the flat-topped Mk. I canopies - with more engine power the extra drag was seen as worth it for the extra visibility. In the Spiteful and Sea Fury the cockpit as a whole was raised relative to Spitfire and Tempest.

Aaron_GT
02-05-2009, 03:28 PM
b) Perched up really high so your head becomes a super target with no armor but you get a nice view through the aiming reticule.

Wasn't it possible to raise the seat up for landing?

jayhall0315
02-05-2009, 03:58 PM
Originally posted by Aaron_GT:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely.

This was tried on a number of planes - the Gloster design to the same spec as the Whirlwind, the Pz.11 and proposed for RAF fighters in the early 1930s. Turned out it made things harder to hit in the end.

In terms of the sight angle it was an issue, but making the hood taller added drag and would mean a slower plane so less chance of beingin guns range. In the F4U the bigger angle was due to a higher seat position being required to make landing visibility better because the cockpit was moved back to make room for the fuel that was moved from the wings to make room for more guns, so it was pretty accidental!

In the Spitfire a periscope was tested to improve angle but was impractical. The Malcolm hood allowed a slightly higher seat position than the flat-topped Mk. I canopies - with more engine power the extra drag was seen as worth it for the extra visibility. In the Spiteful and Sea Fury the cockpit as a whole was raised relative to Spitfire and Tempest. </div></BLOCKQUOTE>

Hmmm, interesting. So you dont think it would be possible to just slightly wedge the guns up by a little bit and recalibrate the HUD so that visually the crosshairs appear higher above the nose. Still seems to me that this would immediately have a noticeable impact on pilot accuracy, especially in tight turning fights.

M_Gunz
02-05-2009, 03:58 PM
I dont mean angle them up towards the ceiling, just about3-5 degrees quite likely.

The more of that you do, the more you limit your effective range near and far for the sight itself.
You want the bullets to travel as much along the path you're flying at the moment as possible which is a compromise anyway
since trajectories curve and the sight line crosses through that curve.

You read war stories from different pilots, often they describe shooting just as the target passes under the nose.
So much detail is left out though that it's only a clue given rather than a course in gunnery.

Galway, I had a friend who before he joined the Navy had worked on a Curtiss project plane to use a 75mm and proximity fuses.
That was a bomber buster that never got produced, I don't think that a flying prototype was even made but the gun system and
fuselage was and near cost him his chance to join up when some jerk fired the thing as he was walking under the muzzle, his
ears didn't take it too well for a while but he passed the hearing test later anyway.

thefruitbat
02-05-2009, 04:14 PM
haha, have you heard of a plane caled the 190?

Aaron_GT
02-05-2009, 04:18 PM
So you dont think it would be possible to just slightly wedge the guns up by a little bit.

That was the mechanism for the vertical component of convergence, so that was possible, but I don't recall having read of it being done to cure sight angle issues, and that seems to have taxed designers at the time enough to consider periscopes and moving the whole cockpit up. If setting the vertical convergence to 100 yards and horizontal to, say, 300 yards had helped then I am guessing it would have been done, and since it was tried in the 30s and abandoned I am presuming that there is some reason it didn't work. But I've only read that it was abandoned not a detailed exposition of why. So I am curious as to why it didn't work as you are - M_Gunz probably has the answer, but some diagrams and trig would help http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

X32Wright
02-05-2009, 04:26 PM
It's a valid observation all of this http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif The reason that the 'camera' or 'player perspective' is fixed in il-2 is because Oleg had to deal with graphic card limitations when this game was made back in 1998/99 when 128/256MB video cards were the 'state of the art' http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

If you look carefully, you will notice that on some of the cockpits, what looks like a 3d model of say a panel or gauge is actually a 2D flat polygon mapped with 'texture maps' (image files) with 'edges' cut out using 'alpha channels' (clipmap). This approach is very noticeable in the I-185 M-71 specially with the blue piping and gauges. This is also noticeable on other cockpits like the 109/Tempest etc.

As for the issue of center of crossshair and fuselage space, you are right you do have some more space in the Corsair than other planes for some few seconds of gunnery available. It is even worse for german planes specially the FW. For German plane flyers like me we are used to shootign planes 'blind' and in most cases shooting WHILE THE TARGET IS BELOW the fuselage. Most deflection shooting in the 109/FW is like this.

Finally this camera perspective limitation is the very reason that some people consider the '6DOF mod' (six degrees of freedom) to be a cheat. Why? Because u can reposition your view (get closer to the crosshair or lean etc.) and shoot with better angles and perspective during deflection shots without the limitations of the 'fixed default perspective/view'.

I definitely know the advantage of this specially seeing this work on DCS:Black Shark eventhough I do not have TIR. I am using the joystick's 'HAT switch' in BS to move my view around like it is a 6DOF TIR.

R_Target
02-05-2009, 06:02 PM
Originally posted by Aaron_GT:
In the F4U the bigger angle was due to a higher seat position being required to make landing visibility better because the cockpit was moved back to make room for the fuel that was moved from the wings to make room for more guns, so it was pretty accidental!

Pretty much sums it up. Grumman went the other way, putting the tanks under the pilot and sloping the nose toward the front of the plane for maximum visibility. The resulting tubby fuselage left room in the lower cowling for intercooler, oil cooler, and armor plate.

cmirko
02-06-2009, 01:37 AM
Originally posted by jayhall0315:
.... but I would be in favor of a new type of server style that is almost identical to the current coop mode where once you get shot down, you stay down until the last guy flying dies or lands. This would totally eliminate 98% of the ramming, slamming, head ons and crap like that, even for open cockpit servers. It would mean that you would have to value your 'virtual' life more and thus folks would begin to fly more realistically.

actually there are a few of the servers you "asked" for in upper paragraph http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

COOP servers, but not just for one mission http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

check my sig for further details

S!

M_Gunz
02-06-2009, 05:24 AM
Originally posted by Aaron_GT:
M_Gunz probably has the answer, but some diagrams and trig would help http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

You want the shots to go as much along the path you're flying as possible for the same reason that you want to avoid firing
while in slip. The more the trajectory angles off your forward path, the more the bullets will have a component of motion
sideways to the sight line and that changes with speed so go try to predict the effect on top of what's already there.

What's already there is bullets dropping with gravity (not flying straight along the sight line), any bank or tilt the plane
may have including pitch trim for the speed you're flying, turn acceleration, relative speed of you and the target adding to
muzzle velocity, pure speed adding to MV changing the drag on your shots, air density at your altitude doing the same, and
what-all else I haven't thought of -- oh yeah, and convergence of wing guns with a number of tricks and effects messing into it.

On your side is that you are using automatic weapons and not depending absolutely on the gunsight anyway. Often enough close
still hits or is a tiny correction away or just pause and fire again because the target is moving into the line of fire.

The gunsight is only "right" under certain conditions at certain ranges anyway. If you don't follow the target but instead
cut across his path you can arrange to not have him go below your nose until after you've fired (or held fire if it would
miss) though you will get a shorter shooting time. Big plus with that is that you will most likely be hitting from an angle
where he is not armored (unless it's an IL2 or like, then only maybe) and has not much plane between you and him or his engine.

A good 1/2 second burst makes a moving line or pattern (wing guns) in the air that is more than just a crosshair, you only
need to place that where the other will cross into it. You can even wave it around a bit with some rudder but that's tricky
to do much of with the gyro and p-factor and wash effects though you can always blame the plane or Oleg if you miss. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

horseback
02-07-2009, 10:28 AM
The positioning of guns and gunsight was often secondary to the designer's need to cram as much engine into as compact a package as possible. Performance was the first priority, because in practice, most kills were ambushes or made from zero deflection (ie, from directly behind your intended victim), so that the victorious pilot set up his shot with maximum visual advantages.

Now in the case of the Corsair and Hellcat, you're looking at aircraft designed for the only fighter pilots in WWII who had been trained from the ground up for deflection shooting; the need for good visual angles was well understood by BuAir, and if you wanted to win a contract to build fighters for them, you catered to their requirements. Those sight lines also made it much easier to land aboard a carrier as well.

The Spitfire was built with different requirements in mind; in 1934, there was no effective radar system, and I doubt that RJ Mitchell (or Willie Messerschmitt) was aware of the possibility of one. The need for an intercepter then was for extremely high performance in the form of climb, acelleration, and level speed, with enough maneuverability and firepower/ammo to make multiple effective passes at attacking bombers.

Bombers are relatively stationary targets, and slower by far than fighters, so as long as you could see them over your cowling, it was all good. The idea of fighter to fighter combat for the high performance interceptors like the Spit and the 109 was at best, secondary; in the mid-thirties, many theorists believed that the air superiority role over the front lines would still be filled by the more maneuverable biplanes, which would be 'too hard' for the high speed monoplanes to track down and destroy.

Raising the guns' angle in the Spit would be well nigh impossible; the wing is thin (for speed), and the guns are pretty much limited in the up-down angles. Now streamline the cockpit as much as possible, and the pilot has a very limited filed of view.

Remember too, that a 'real' pilot could move his head about left to right, forward and back to track his opponent, while the current version of the game allows you only two locations for your head, and one usually makes the sight far less effective (and if you're playing off-line, the AI know exactly the moment your canopy framing hides them and use that advantage to change directions 99% of the time, while a human cannot).

TrackIR does a lot to remedy this (second only to rudder pedals, IMHO), but without the 6DOF feature, you're still considerably limited in many more ways than the guys who actually flew these things almost 70 years ago. On the plus side, you have a more comfortable seat and the sure knowledge that you will live throught the experience, so I'd call it a wash.

cheers

horseback

PS-when I first played the original game, I did it with a PCI card with only 32Mb of video RAM, and the first time I tried Forgotten Battles, I was running a ti4200 with 64Mb. How times have changed!

Xiolablu3
02-09-2009, 03:20 AM
Originally posted by horseback:

PS-when I first played the original game, I did it with a PCI card with only 32Mb of video RAM, and the first time I tried Forgotten Battles, I was running a ti4200 with 64Mb. How times have changed!

Yeah I was gonna say, 128/256mb was the total RAM of many high end systems when IL2 was released. Gfx card RAM was much less, around 16/32mb.

M_Gunz
02-09-2009, 01:59 PM
I was running a 1Gz Athlon with 512M RAM and a GF2MX with 64M at the time (late 2001) and Xio, that wasn't nearly high end!