Spinning the P-39

[JG1_Vonrd]

Pretty interesting video on spin recovery in the P-39. I haven't flown it much in GB and can't attest to whether it's modeled to have similar spin characteristics.

This is from the author Tom Burkhalter who has written a group of novels about the air war in New Guinea (I found them to be well researched and enjoyable):

The pilot’s manual for the P-39 Airacobra sets out a recovery technique that’s a little more complicated. There are two phases, pre-recovery and recovery. In the pre-recovery phase, the pilot has to close the throttle, set the propeller control to the low RPM position, and pull the control stick into your lap. Get it? The throttle is at your left hand, the propeller control is just behind the throttle, so that’s a one-two movement as you pull the stick back into your lap.

Now remember the airplane is not in a controlled maneuver. The manual describes the spin as being oscillatory in rate. Sometimes it spins fast, sometimes it spins slow. You don’t have any control over the rate. You have to decide when the airplane is slowing down or speeding up. You have to know that because, to effect recovery, you have to apply full opposite rudder when spin is at its slowest.

 

So you wait for the rudder to take effect and push the stick full forward while applying ailerons against the spin. The actual language used in the manual is interesting: “The spin is usually oscillatory in rate, and it is mandatory that the opposite rudder be applied when the spin is at its slowest.” I particularly like that word “mandatory.” It’s the sort of emphasis you don’t often find in a pilot’s manual.

If you follow the procedure above, “…the airplane will recover in one-half turn. If the procedure is not followed closely, the airplane may not recover.” I think the implications of that last sentence deserve examination. You must follow the procedure closely, i.e., you do exactly what the manual says, or you’re going in.

Here's the video:

 

[Mauf]

From what I understand about the P39 spin: Problem is the center of gravity with the engine behind the cockpit. In spins, the goal is to get the nose down to stablize flight and regain surface control. The P39 has the problem that it lacks weight in the nose which makes it harder to get it pointed down in the spin. Therefore, it needs coaxing by working with the oscillation (similar to how swings on the children's playground work) -> increase the oscillation amplitude so the nose eventually tips out of the spin attitude. That's probably also why a pretty flat spin without much oscillation was considered unrecoverable -> just eject, the time needed to build up the momentum was greater than the time to impact.

 

I remember reading somewhere that changes were made to the nose gun not to eject spent casings to keep more weight in the front to counter the spin characteristics. No idea if that's true though.

 

 

[6./ZG26_Klaus_Mann]

The Aircraft only exhibited this behaviour with low or no ammo. With Full Ammo it was stable.

[6./ZG26_Klaus_Mann]

Also: The earliest Models had the light 20mm Gun, later 37mm Gun was heavier.

I'm not certain if our ingame Soviet P-39 still has armor behind the Engine, as the Soviets really didn't like it.

Edited May 25, 2021 by 6./ZG26_Klaus_Mann

[III/JG52_Otto_-I-]

Quote

Anecdotally I believe the P39 did have problems with spin recovery, the solution was to make sure spin recovery was well trained and drilled into pilots. There is a report here:
http://www.wwiiaircraftperformance.org/P-39/P-39Q_Spin.pdf
P-39 Airacobra
"Its unique engine location behind the cockpit caused some pilot concern, but this proved to be no more of a hazard in a crash landing than with an engine located forward of the cockpit. The P-39's spin characteristics, however, could be quite a problem if recovery techniques were ignored. "
By contrast the Me 109 was aid to be the easiest aircraft in the world to recover from.

I´ve read this from other WW2 aircraft forum

The P-39 had a very specific technique for recovering spins, unlike Bf-109 that it was one of the most easy aircraft of WWII in recover spins. I thinks that we have not this different in the game.
Spin recovery in game is almost equal of fake for all airplanes in game.

Edited May 25, 2021 by III/JG52_Otto_-I-

[Bremspropeller]

Taking out the wing guns in the later odels probably helped in reducing auto-rotation inertia.

Edited May 25, 2021 by Bremspropeller

[von_Tom]

 

 

Watch closely as the P39 disappears at 58 seconds...  See, so it is real when it happens in-game!

 

von Tom

[BlitzPig_EL]

The P39 was originally designed around the 37mm cannon.  The 20mm nose gun came later for the export model for the RAF, the P 400, many of which were taken over by the US and sent to the Pacific after the RAF cancelled any further orders for the aircraft.

[LukeFF]

8 hours ago, 6./ZG26_Klaus_Mann said:

I'm not certain if our ingame Soviet P-39 still has armor behind the Engine, as the Soviets really didn't like it.

 

It's an optional loadout that's combined with removing the .30 cal MGs, yes.