Recoil When Firing

[Dingy]

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

[AKSeaWulfe]

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

[Ripsnort]

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"

[AKSeaWulfe]

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

[Duckwing6]

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.

[funked]

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

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.

 

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

[AKSeaWulfe]

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

[funked]

It's not so simple SW.  See my post above.

[AKSeaWulfe]

Funked you gotta be kidding me... Math?
I SUCK at math.

I'll just take your word for it. :-)
-SW

[Jimdandy]

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.   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  

[flakbait]

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
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
   

[This message has been edited by flakbait (edited 02-22-2001).]

[Fishu]

Recoil effects in the game aren't too great..
You'll hardly notice it if you don't spray your guns for _several_ seconds.

[funked]

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.

[funked]

To the contrary Fishu, just what do you think is causing the quite large dispersion of fire from the guns?

[Jigster]

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).]