Aces High Bulletin Board

General Forums => Aces High General Discussion => Topic started by: Dingy on February 22, 2001, 01:27:00 PM

Title: Recoil When Firing
Post by: Dingy on February 22, 2001, 01:27:00 PM
Guys,

Is recoil modeled for our weapons?  The reason I ask is because I was watching a show on HIstory Channel where they interviewed a pilot who used to fly the F-86 Sabre in Korea who reiterated a story...

He and his wingleader were chasing a pair of Migs back across the front and were slowly gaining on them.  This was the first time this pilot had ever seen a Mig in combat and so was a little anxious to get his first kill.  Anyway, they were still a bit outa range of the migs for guns but they were quickly running out of fuel to continue the chase so the rookie decided to fire his guns despite his leaders protest no to.  Anyway the end of the story was they had to let the Migs go because the recoil of the 6 (8?) 50s on the Sabre would slow it down almost 30MPH!

Wow!!  I've taken some long shots before but when booking on the straight and level, I've never seen this sort of decelleration in either a P51 or P47.

Thoughts?

-Ding
Title: Recoil When Firing
Post by: AKSeaWulfe on February 22, 2001, 01:32:00 PM
Recoil is there, but I don't believe it has the "impact" on flight as it should. I remember watching a show on Discovery when wings use to come on. They were talking about P38s at the time and said when all 4 .50s and 1 20mm was fired it was like hitting a brick wall. Something in the area of 50MPH slow down.

Although I'm not sure if it's from recoil or just the force of the air escaping the gun barrels(which in turn pushes on the plane).

Actually I have no idea what it's from. :-)
-SW
Title: Recoil When Firing
Post by: Ripsnort on February 22, 2001, 01:34:00 PM
Haven't tried this, but someone else posted:

"Start on the runway with engine on, move forward a smidge to get brakes released, then shut engine off.  Fire all your guns.  The A/C will move backward"
Title: Recoil When Firing
Post by: AKSeaWulfe on February 22, 2001, 01:37:00 PM
That's all good Rip, but unfortunately that's with no forward accel acting on the plane. I'd suggest getting the plane up to 240MPH then firing all guns, see what happens then.
-SW
Title: Recoil When Firing
Post by: Duckwing6 on February 22, 2001, 01:39:00 PM
I noticed it recently in an F6F in auto climb, slows ja down quite a bit (5mph  can't recall the vallue) and you can se the nose drop in auto as the auttrim tries to maintain airspeed.
Title: Recoil When Firing
Post by: funked on February 22, 2001, 01:42:00 PM
We covered this a long time ago.  Recoil is there and the levels are correct.

Here's the math for the P-51:  http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/002844.html (http://bbs.hitechcreations.com/smf/Smileys/default/Forum1/HTML/002844.html)

Here is a speed vs. time plot from a simulation I created.  P-51D at Sea Level, MIL power, firing all 6 guns.  This uses the model from the link above.  AH matches it pretty darn well.

 (http://www.raf303.org/funked/p51recoil.jpg)

[This message has been edited by funked (edited 02-23-2001).]
Title: Recoil When Firing
Post by: AKSeaWulfe on February 22, 2001, 01:44:00 PM
Just tried this offline:

Took up a P38 75% gas and flew level(leaving LEVEL autopilot on) and waited until the plane reached 240MPH.

Fired all guns, accel decreased slightly but continued accelerating.

250MPH: Accel decreased a little more, but continued accelerating.

270MPH: Accel decreased significantly, but continued accelerating slowly.

300MPH: Accel stopped for the most part, still a very minute amount of acceleration.

Since the plane's were said to decrease in speed in level flight, and the above test was done in level flight I don't think the decelleration values are high enough.

A slight loss in acceleration isn't what I'd call "hitting a brick wall".
-SW
Title: Recoil When Firing
Post by: funked on February 22, 2001, 01:51:00 PM
It's not so simple SW.  See my post above.
Title: Recoil When Firing
Post by: AKSeaWulfe on February 22, 2001, 01:53:00 PM
Funked you gotta be kidding me... Math?
I SUCK at math.

I'll just take your word for it. :-)
-SW
Title: Recoil When Firing
Post by: Jimdandy on February 22, 2001, 02:10:00 PM
I think the biggest reason the recoil doesn't seem right it because you can't feel it. The changes in acceleration would feel more dramatic than what you see on the dial. Until they can come out with affordable full scale flight simulators all you will see is the gauge move but it's not going to throw you against the harnesses like firing the gun would. Of course you can simulate this effect at home by having a friend jerk your computer chair around while you fire.  (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif) My favorite at home sim is the cockpit oil fire. Anytime I'm smoking I light off a can of WD 40 in my face. You want to talk REALISM. YEEEEEEEEE HAAAAAAAA  (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
Title: Recoil When Firing
Post by: flakbait on February 22, 2001, 02:16:00 PM
If I can get the following info from someone about some guns I'll be happy to figure just how much recoil force each gun generates:

Bullet weight (in ounces)
Gun weight (in pounds)
Powder weight (in ounces)
Muzzle velocity (in feet a second)

I'll post what I figure out once I can find/get the gun info. About the only thing I'm missing is powder weight for the various shells and gun weights.

-----------------------
Flakbait [Delta6]
Delta 6's Flight School (http://www.worldaccessnet.com/~delta6)
Put the P-61B in Aces High
"With all due respect Chaplian, I don't think God wants to hear from me right now.
I'm gonna go out there and remove one of His creations from this universe.
And when I get back I'm gonna drink a bottle of Scotch like it was
Chiggy von Richthofen's blood and celebrate his death."
Col. McQueen, Space: Above and Beyond

  (http://www.worldaccessnet.com/~delta6/htbin/delta6.jpg)  

[This message has been edited by flakbait (edited 02-22-2001).]
Title: Recoil When Firing
Post by: Fishu on February 22, 2001, 02:27:00 PM
Recoil effects in the game aren't too great..
You'll hardly notice it if you don't spray your guns for _several_ seconds.
Title: Recoil When Firing
Post by: funked on February 22, 2001, 02:29:00 PM
Jimdandy I think you get it.  Even a really small vibration amplitude can shake you up if the frequency is high enough.  But since we are using eyeballs to look at a screen, we are noticing the displacement amplitude, not the acceleration amplitude which you sense in real life with "seat of the pants" and the good old Mk. I Inner Ear Accelerometer.
Title: Recoil When Firing
Post by: funked on February 22, 2001, 02:31:00 PM
To the contrary Fishu, just what do you think is causing the quite large dispersion of fire from the guns?
Title: Recoil When Firing
Post by: Jigster on February 22, 2001, 02:59:00 PM
There is significant pitch-down when firing in some planes, but this doesn't seem to correlate to recoil much.

Also, me and a few squadies did a test that had some startling results...apparently recoil isn't the same on all computers.

I discoved the good ol' PT death blossom, where you can fire the Bofors off the side of the ship and get to spinning at an incredible rate, apparently because water is frictionless as the moment (or the PT hull is)

Where as my squadies (and Ding was one of them) could only get it to turn around a bit, albeit still shaking and bouncing from the recoil. After following my exact instructions several times to no sucess

I've never been able to get the planes to roll backwards by firing, regardless of wing, moving, stopping and then firing and any other prescribed technique.

Many other people don't seem to see the serious nose down pitch upon firing either, so wtfgas.


- Bessy

[This message has been edited by Jigster (edited 02-22-2001).]
Title: Recoil When Firing
Post by: flakbait on February 22, 2001, 03:26:00 PM
Here's the recoil figures for an Ns-37 cannon, since we're getting one in 1.06:

Gun weight: 330.69 lbs
Muzzle velocity: 2952 ft/sec
Shell weight: 25.72 oz
Rate of fire: 260 rounds/min
Muzzle energy: 217,692 ft-lbs
Recoil velocity: 18.991 ft/sec
Recoil energy: 194.067 ft-lbs

As a reference, a 240 grain bullet from a .44 Remington Magnum kicks with a force of 14.44 ft-lbs.

Right about now having a calculation for powder volume would help a lot. Since just about every large caliber shell has a bottle-neck it's difficult to figure the exact volume it can hold. I'll post more when I find the info.

-----------------------
Flakbait [Delta6]
Delta 6's Flight School (http://www.worldaccessnet.com/~delta6)
Put the P-61B in Aces High
"With all due respect Chaplian, I don't think God wants to hear from me right now.
I'm gonna go out there and remove one of His creations from this universe.
And when I get back I'm gonna drink a bottle of Scotch like it was
Chiggy von Richthofen's blood and celebrate his death."
Col. McQueen, Space: Above and Beyond

  (http://www.worldaccessnet.com/~delta6/htbin/delta6.jpg)  

[This message has been edited by flakbait (edited 02-22-2001).]
Title: Recoil When Firing
Post by: -duma- on February 22, 2001, 04:25:00 PM
Jig, you sure they didn't just have the PT throttle down a bit? Unless it's on full you won't get the full Death Blossom effect.
Title: Recoil When Firing
Post by: Jigster on February 23, 2001, 02:34:00 AM
Nope. My old machine was apparently special.

I had both running side by side today and couldn't get the same results be executing the same thing.

Oreo.

Another articfical handicap maybe?  (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)

Title: Recoil When Firing
Post by: GRUNHERZ on February 23, 2001, 02:47:00 AM
One thing that constantly surprises me is chogs climbing up to my 109G10 in a zoom climb, firing their 4 cannon all the way up and still coming nearly up to my level. Or at least hight enough that when I stall and drop they end up above me. This makes no sense whatsoever. The 109G10 outclimbs chog by a bunch and I never try climbing over one unless im pulling away and have good seperation. Something must be wrong if a poor climber like chog doesnt get affected by this force in real combat.
Title: Recoil When Firing
Post by: GLASSSES on February 23, 2001, 08:18:00 AM
I've seen it also Grun the chog has now an amazing zoom ability. Even when the laser cannons are in full blast power.

------------------
I may 4 eyes but you only have on wing
Title: Recoil When Firing
Post by: -towd_ on February 23, 2001, 09:14:00 AM
read a refrence about c hog main thing the guy noticed was she lost speed in a dive when firing . hey but funked god of math says its right , but then he always does. dosent he
Title: Recoil When Firing
Post by: funked on February 23, 2001, 10:10:00 AM
Towd you are either a liar or you don't read very many of my posts.  I find fault with this game quite frequently.

But the recoil (at least on the P-51D) is correct.

The reason my calculations usually agree with the HTC model is not because I am cooking up numbers to make them look good, as you have insinuated.  The reason is that HTC do a damn good job on most of the vehicle dynamics in the game.

You can't keep classifying people as cheerleaders just because they disagree with you.

[This message has been edited by funked (edited 02-23-2001).]