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jensenpark
02-28-2004, 11:09 AM
Wonder if this has been discussed on the forums before:

Why isn't gun recoil with regards to airspeed modeled into the game?

I recall reading how some of the larger-cannon firing Yak's or P39s would have recoil slow the plane up to 45kmh...('course the k4 and p-47, etc would be same)

Would certainly make it easier/more realistic to escape/fight someone on your six who is flaying away at you with a big nose cannon if there was a cause and effect.

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"Death before unconsciousness" - Uncle Duke

jensenpark
02-28-2004, 11:09 AM
Wonder if this has been discussed on the forums before:

Why isn't gun recoil with regards to airspeed modeled into the game?

I recall reading how some of the larger-cannon firing Yak's or P39s would have recoil slow the plane up to 45kmh...('course the k4 and p-47, etc would be same)

Would certainly make it easier/more realistic to escape/fight someone on your six who is flaying away at you with a big nose cannon if there was a cause and effect.

http://images.ucomics.com/images/doonesbury/strip/thecast/duke2.jpg

"Death before unconsciousness" - Uncle Duke

BM357_Raven
02-28-2004, 11:26 AM
Isn't there? Haven't flown the Cannon firing planes as of late, but there seemed to be an affect... Especially in turns.. No? hmm..

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FennecP
02-28-2004, 11:45 AM
They do cause recoil. Its most noticable when you're sitting on the runway.

Because most heavy guns lack a substantial rate of fire, the deceleration they cause isn't very noticable in flight.

But if you fly level at a constant speed, and fire the weapons continuously, you will be able to see the effect. The FW-190 with MK108 is noticable, and Me-262.

jensenpark
02-28-2004, 02:33 PM
There is a recoil effect such as the plane movement...but not the loss of speed that has been noted by fighter pilots in the war. It's widely mentioned in many books written by pilots from the war.

Try it in the Yaks, or Me 262 firing all guns/ammo in one long burst. At even flight, the planes still accelerate, where the recoil should cause speed/energy degradation...

http://images.ucomics.com/images/doonesbury/strip/thecast/duke2.jpg

"Death before unconsciousness" - Uncle Duke

Hunde_3.JG51
02-28-2004, 02:53 PM
Like someone else said, take a 190 even with just 20mm and get your speed up. Use no cockpit view and fire & hold your cannons and there is a noticable drop in speed. I assume it is the same for all planes.

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jensenpark
02-28-2004, 03:01 PM
Maybe we're all playing a different game. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-indifferent.gif

I just tested again, full difficulty, with just speed bar on, for a Me262 and FW 190 with the 108 cannon pod. Now you don't get any bigger hitters than that for possible recoil.

Both continued to increase speed even when firing all cannons, and firing off the whole ammo load.

Speed bar showed continual speed increase...when it should have showed a considerable (20 - 40kmh)drop in speed from just one shot, if what has quoted by WW2 pilots is true.

No change in speed increase whether firing or not.

http://images.ucomics.com/images/doonesbury/strip/thecast/duke2.jpg

"Death before unconsciousness" - Uncle Duke

Agamemnon22
02-28-2004, 03:27 PM
Even the P-47 loses 10-20 kph if you hold down both triggers for a bit.

FennecP
02-28-2004, 04:32 PM
Lets do the math and see how much deceleration it would cause.

For example, NS37 on Yak-9T. Lets just assume that the gun is 100% efficient.

Shell is 735G. Muzzle velocity is 900m/s

Airplane weighs 3,000kg, velocity is, lets say, 50m/s.

Shell momentum is 661.5 kgm/s
Plane momentum is 150,000 kgm/s

Plane momentum after firing is 149338.5 kgm/s. Divided by its weight, is 49.78 m/s. So it lost 0.22 m/s by firing the gun, which is 0.79 km/h. Plz feel free to check my math http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

So a P-39 or Yak-9T firing its gun once would slow down less than 1km/h per shot. To slow it down 45km/h would take more than 50 shots, and to shoot 50 shots would take half a minute (if it even had that many rounds).

The only time it would be noticable, would be if you have a lot of these guns (like Me-262 or P-47), or a much higher rate of fire (like the GAU-8).

For comparison, a 1 second burst from P-47 has about 7 times the momentum of a NS37 round. A loaded P-47 (twice as heavy as a Yak-9) would slow down about 2km/h from that.

[This message was edited by FennecP on Sat February 28 2004 at 03:51 PM.]

bashii
02-28-2004, 05:32 PM
Funny this is here because today I was flying the IL-2 and one wing cannon was knocked out so I was only firing from one side. It was very noticeable that with every burst the plane slowed on the side that was still functioning and rotated toward that side. Made aiming nearly impossible with any sort of extended firing.

jmmoric
02-28-2004, 06:54 PM
So the rear-gunner actually has two functions, shooting at the enemy and accelerating the aircraft http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

rgds

SUPERAEREO
02-28-2004, 07:31 PM
I have actually seen people in damaged planes online firing off all their guns when landing in order to decelerate more quickly.

It seemed to work, but the squadmates just spawning on the airport were not that thrilled... http://ubbxforums.ubi.com/infopop/emoticons/icon_biggrin.gif

S!

Lawn_Dart
02-28-2004, 11:16 PM
Jensenpark, you keep mentioning that your plane "keeps accelerating"...are you starting the test at a constant speed, or are you testing while accerating? Only while flying at a constant speed will you notice a deceleration from firing canon. If you are trying your test while accelerating, you will never see much change in the rate of acceleration since while accelerating the engines are producing much more thrust than the cannons recoil, so at best your "rate" of acceleration will be a bit slower...but you will still accelerate nonetheless.

The pilots accounts you speak of relate to an already "balanced" (I.E. flying level at cruise speed or decelerating) aircraft. But if you are expecting to slam the throttle forward to WEP and then fire the cannons and have their recoil slow you down for any length of time...no, that won't happen.

Menthol_moose
02-28-2004, 11:25 PM
try firing your guns on the ground and see what happens http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif



Eh, mates! What's the good word?

Curly_109
02-29-2004, 06:03 AM
I heard some times ago in some BoB documentary on my national TV some actual hurry pilot saying "when I open fire from 8 guns, my plane seems to 'slower' in airspeed" not exact words but that's it.
As far this matter concerns it's pretty good shown in-game... But maybe not EXACTLY as in REAL WORLD.... this is only a GAME...

see what Menthol_moose says http://ubbxforums.ubi.com/infopop/emoticons/icon_wink.gif