Newbie... crazy STALL!

[Manuel]

Hey guys,

 

I recently bought P51D and started flying a bit... now what happened was, that during a fight, I pull on to the stick... more and more and then my plane turns crazy. I think this is not stall any more.. it turns (rolls) in one directeion very fast (speed is not low). I first thought it had to be something with my control config. But that was not the problem. I then saw a couple of videos. There they could turn no matter what.

 

I attach the track and please give some advise to a new (mustang) pilot.

 

Cheers,

 

Manuel

New Track.trk

[Tank615]

It's called a wing tip stall. The P-51 is known for it. One way to avoid this is to lower the elevator effectiveness in the axis controls. Use full opposite rudder to pull out of it.

Edited December 13, 2012 by Tank615

[SimFreak]

I didn't watch the track. It could be accelerated stall.

 

http://en.wikipedia.org/wiki/Stall_%28flight%29#Accelerated_and_turning_flight_stall

[VH-Rock]

Hi Manuel,

 

Tank & SimFreak are correct - even though the speed is still high, you are entering an accelerated stall - a trait for which the Mustang is well know. The trick with the Mustang is to be very smooth with your stick and, as Tank suggests, you could try lowering the pitch saturation in the control axis setup. She's a beautiful aircraft to fly once you've got a few hours in her and understand her a little better - best of luck!

[VIMANAMAN]

When pulling It's essential to keep the ball centred - i.e. no sideslip / equal aerodynamic flow / drag with each wing. AND you must remember the 51 has far more elevator travel than is required (at high speed anyway) to manoeuvre to the edge of the envelope i.e. a delicate touch is required as Rock says - practise finding the high speed stall buffet / vibration with the ball centred pulling at highish speed.

 

And remember not to exceed much over 7G or the wings will part company :)

[Manuel]

Hey guys, thanks for all your replies.

 

So I am pulling to hard. I will train to get it smoother. You know it's kind of hard in a dog fight, where you want a fast turn rate (oviously faster than your oponent) and if you pulling too much, well there you go.

 

Any clue about ideal turn speed for P51D? Turn with full throlltle / half / quarter / whatever?

 

Is there a speedbrake?? I pushed the button but nothing happend watching the outside.

 

Thanks for all your help!

[sobek]

Any clue about ideal turn speed for P51D? Turn with full throlltle / half / quarter / whatever?

 

IIRC around 250mph-ish, but i could be wrong. Regarding throttle, there really is no answer, except, whatever keeps you at corner speed. The rest is dependant on what maneuver you are doing, how your energy compares to your opponent, etc.

 

Is there a speedbrake?? I pushed the button but nothing happend watching the outside.

 

No, there is none. Yaw hard or burn speed with high alpha maneuvers. You can also use the flaps, but you need to take care to not overstress them. Directions for maximum flap speeds are in the pit on the left side, IIRC.

[VH-Rock]

 

Is there a speedbrake?? I pushed the button but nothing happend watching the outside.

 

Thanks for all your help!

 

No speed break in the P-51 - If I need to slow down quickly (not very often), I try side slipping a little to scrub off the extra speed :)

[EtherealN]

Just make sure to be prepared for the lift-loss when side-slipping. (I usually use it for controlling descent rate since it is pretty effective at that when you don't have other measures for the purpose.)

[VH-Rock]

Just make sure to be prepared for the lift-loss when side-slipping. (I usually use it for controlling descent rate since it is pretty effective at that when you don't have other measures for the purpose.)

 

Indeed, I must say the only time I ever really need to slow down quickly is if I'm coming in a little to hot for landing

[EtherealN]

Sounds like a different application though: I use it specifically to increase descent rate without losing airspeed. But of course that's all a question of what you simultaneously do with alpha etcetera.

[Kwiatek]

Personally i think that DCS P-51 is little to easy to prone to accelerated stall. I think it shouldn't happend so fast at medium speed range comparing to stick momevement ( not violents manouvers). But i didnt flew real P-51 alhought i fly IRL aerobatic planes (Zlin 526F) and gliders. I really wonder what would say real P-51 pilot who tried DCS P-51.

[EtherealN]

Kwaitek, the problem is in arm of movement: the movement you do on your stick at your desk is not the same as when moving the real stick in a real plane; and also, you don't feel the forces the same.

 

Since you fly gliders, do the standard Step2 exercise; fly close to stall, and fly close to Vmax. Compare forces on the stick. With a desktop simulator; note how the forces are identical...

 

Regarding real P-51D pilots: TFC operates P-51D for airshow and movie work, which is what this P-51D simulation is based on. It is validated by professinal, in-house, P-51D pilot.

[Echo38]

Personally i think that DCS P-51 is little to easy to prone to accelerated stall. I think it shouldn't happend so fast at medium speed range comparing to stick momevement ( not violents manouvers). But i didnt flew real P-51 alhought i fly IRL aerobatic planes (Zlin 526F) and gliders. I really wonder what would say real P-51 pilot who tried DCS P-51.

 

P-51 weighs, what, five times as much as your aerobatic airplane? Twenty times more than a glider? Not sure about the exact figures, but the point is that the P-51 weighs many times as much as the airplanes you've flown. Higher mass means higher stall speed, all else constant. High stall speed means you're gonna stall with relatively small stick deflections, especially with a highly-effective elevator.

 

IIRC around 250mph-ish, but i could be wrong. Regarding throttle, there really is no answer, except, whatever keeps you at corner speed. The rest is dependant on what maneuver you are doing, how your energy compares to your opponent, etc.

 

Generally, you always want max power in combat, unless you're over (or about to be over) corner turning speed (while turning), and excepting throttling back as necessary to avoid overheating the engine. As Sobek indicated, corner in the P-51 is very roughly 250 MPH (give or take ~20 MPH; I also am unsure of the exact figure, but you can test it yourself, if you have the patience and finesse). Bear in mind that corner turns are not sustainable, so if you're at sea level, make sustained turns at 250 MPH will not go well for you. Too wide. Sustained turns should be done at a much lower speed, closer to best climb speed (~180 MPH or so; best climb speed varies based on mass, power, and air density). Again, I'm not sure exactly what best sustained turn speed is, but it can be tested if you have a good joystick & pedals, a steady hand, and patience.

 

Test procedure is simple: fly a coordinated turn under set conditions, as close as possible to combat conditions. Ball centered, max power, etc. Turn until your speed reaches 150 MPH, then hold it in that turn, at that speed, without gaining or losing altitude. Time how long it takes to make a 360-degree turn. Get a fresh ship so that your fuel state & engine temperature are the same as the last test, and repeat, this time at 160 MPH, et cetera.

Edited December 14, 2012 by Echo38

[Tank615]

Manuel,

One thing I forgot to mention is that the P-51 makes a distinctive whistling sound when it is about to enter an accelerated stall. If you listen for this during your turns you can avoid or at least expect the stall. The stall is so violent because the stall occurs at the wingtip. This is due to the design of the aircraft wing.