Utilizing the P-51D's instability

[Widewing]

Flying the P-51D, exploring the absolute limits of its flight envelope led me to find and unusual quirk in its flight dynamics.

Most people would agree that no other fighter can burn off speed faster than an F4U, which can use (and did in real life) its main gear as speed brakes. I thought that as well, until today.

How about a P-51D flying at 330 mph, decelerating to 130 mph in less than 4 seconds, while presenting an almost impossible target? I filmed the following offline and asked Murdr to film it online, by following me. Done correctly (it takes a lot of practice), you can shake off anything on your six. At least for a brief period, perhaps long enough to reverse your fortunes. I tried this in about a dozen other fighters. None could perform the maneuver.

Fuel was 25%, meaning the fuselage aux tank was empty.

The films are very short, 15 to 20 seconds, but they are very interesting.

Mustang Maneuver 1

Mustang Maneuver 2

My regards,

Widewing

[Xasthur]

Very interesting. This is similiar to a maneuver the 109 can perform, though it's maneuver is safe to use at 1000 feet abg.

Cheers Widewing

[mtnman]

That looks a lot like a maneuver I do with my radio controlled planes.  To do it, I throw both control gimbals into the top inside corners, or both into the top outside corners.

That would be full throttle, full down elevator, full left aileron, and full right rudder.  Or full throttle, full down elevator, full right aileron, and full left rudder.

I generally prefer to do it while nose up at least a bit, sometimes even vertical.  Letting my controls go neutral stops the maneuver, at least with my RC planes.

I've done it with RC Corsairs, Ponies, Cherokees (Piper), Ultimate biplanes, and Pitts biplanes.  The aerobatic planes do it best, followed by the war birds.  The Cherokee will do it, but it's not as quick and impressive.  

I don't know how close those planes are to AH's flight model though.  For one, the power/weight ratio is probably quite different.  The wing loading and airfoils are different too...

I've done that manuever in the TA, DA, and offline, and it does work, but I've never tried it in the MA.  I know there were complaints for a while way back when of people doing snap rolls, and (lag?) made them look awful to the guy following.  Those complaints seem to have died down, maybe the smoothing effect HTC added helped?  Use to be called stick-stirring, even though it wasn't...

MtnMan

[Guppy35]

Been watching Dogfights lately Widewing?

Looks like what Don Bryan of the 352nd described himself doing on November 2, 1944 to get a 109 off his tail.

[Xasthur]

It would seem to have very limited use in a decent fight and would be an absolute last-ditch effort in a hope to evade a kill shot. Simply applying power and staying above would leave the attacker in an advantageous position. It would be interesting to actually encounter this maneuver though.

[Anaxogoras]

Are you going to tell us how to do that?  It's really hard to figure out just by watching the movie (the control surfaces don't move during playback).

[B@tfinkV]

have been using the P51 as a low slow turn fighter for some time now, a number of years infact and often with moderate to excelent results.

great post widewing, hopefully some of the P-fifty runs will take note and stop being so timid. Mustang Sally says slow you mustang down.




edit: and the result of this type of flying is largely based on the perception your enemy has of you. If you have got in the opponents head and convinced them you are an easy kill then good things often come to those who take the risks.

too early and you are a sitting duck, too late and you get blasted.....but with perfect timing the mustang is formidable on full flaps and side slip.

[Widewing]

Originally posted by Anaxogoras
Are you going to tell us how to do that?  It's really hard to figure out just by watching the movie (the control surfaces don't move during playback).

Push your stick all the way forward and all the way to the left while applying full right rudder.

Mtnman described it exactly.

While Murdr was flying behind me in the TA running film, I was actually able to flip the Mustang backwards and see his pursuing 109K in my windscreen as he blew past. He said there was no chance to get guns on the P-51 as it literally dropped straight down as it rotated.

Murdr, if you're reading this, maybe you could post a portion of the film...

My regards,

Widewing

[Urchin]

Used to be able to do something similar to that in the AH1 Spit 5.  I think wetrat came up with it... the plane basically spun about its axis and would actually fly backwards for a split second before it stalled and spun.  

It was really wierd, felt kind of like driving on ice feels, when the car just slews around without you really being in control of it.  

It wasn't good for a whole lot, IIRC only a couple planes could do it very well (A6M, Spit 5).

[dtango]

Shhhhh Widewing!!!  Don't be giving away all the secrets of the Mustang!!  You have to make them earn it to learn about stuff like this!

But in the MA you have to do it with a lot more panache you know!  More like this where you don't snap roll it and also lose so much altitude and control...

p-51d_flat_plating

I filmed this a year ago in the MA so the terrain is one that doesn't exist.  The fight was over some hilly terrain and I clipped a tree in the end.

I call it "flat plating" the Mustang in honor of Col. John Boyd's maneuver.  It's a similar concept to his famous maneuver in the F-100 where you present as much of the aircraft's surface area into the freestream air using massive drag to dump your energy like no one's business.  As described in the book by John Coram, it's sort of like turning a manhole cover from it's thin edge to it's flat side surface into the wind.

The secret is to maintain good control in the maneuver so that you recover very quickly from the "flat plate".

Of course though there is one huge difference.  The F-100 had an awesome T/W ratio which allowed you to regain energy like crazy.  You're pretty much out of luck in this category with the Mustang and better hope that you've somewhat equalized the energy margin between you and your opponent to take advantage of the maneuver.

I prefer to use it as my options are running out.  In this case I thought I would try to suprise kumori in his Yak.

Tango, XO
412th FS Braunco Mustangs

[gripen]

Looks like sort of a snap roll. Russian pilots used that kind of maneuver with the I-16 as well.

[Hien]

Yeah, just from the description it sounds like a snap roll to me to.

I use it all the time, but then, I'm almost always about to get shot full of bullets.

I find it quite useful.

[Anaxogoras]

Push your stick all the way forward and all the way to the left while applying full right rudder.

Ok, I was successful at approximating the maneuver, however the severe redout makes me believe that no pilot would attempt this without temporarily losing his eyesight.  No doubt it is effective in AH.

Granted, I have never flown a P-51, but I have done some loops, rolls and spins in a Grob http://www.grob-aerospace.net/index.php?id=88 and boy do you feel the G's!

[SteveBailey]

Awww shucks... don't give the few secrets the pony has away!

This is a nice move  unless you have a second, longer trailer.  For a couple of secs, before you right the ship, you are pretty vulnerable.  Anyone close would have gone by, no doubt pulling hard in reaction and not getting a solution.  A  second trailer will have a nice shot if he reacts accordingly.

Nice film.  

[wrag]

Originally posted by Widewing
Push your stick all the way forward and all the way to the left while applying full right rudder.

Mtnman described it exactly.

While Murdr was flying behind me in the TA running film, I was actually able to flip the Mustang backwards and see his pursuing 109K in my windscreen as he blew past. He said there was no chance to get guns on the P-51 as it literally dropped straight down as it rotated.

Murdr, if you're reading this, maybe you could post a portion of the film...

My regards,

Widewing

Prior to the release of AHII the 109 could nearly turn around in it own length.

Maneuver was something like this..........

apply full left forward stick, apply full left rudder (for maybe 1/2 a second or even less), full reverse rudder, full back stick.  Timing it just right was HARD but worth it!

In AHI the 109s had about as much down vator as up (which SEEMS correct according to info?) but when AHII came along that maneuver was no more, now 109 wallows and nearly refuses to react to down vator?

In fact IMHO HT may have over done the neutering of 109 down vator?

Also the 109 could do a nice left turn in AHI, that IIRC was reported as fact by opposing pilots?

Take it into a climbing left turn apply RIGHT rudder, then left rudder and cut throttle but keep it in a left turn!  Plane should hang there just for a sec then drop and finish the left turn.  I can't seem to get our 109 to do this now?

Another variation USED to be start same climbing left turn BUT at the top and after applying right then left rudder go full right stick right rudder, and full back stick.

All these maneuvers worked somewhat in other planes to a greater or lesser degree but the 109s were excellent.

Interestingly enough these maneuvers now SEEM to work in OTHER aircraft somewhat but the 109s are verbotten?

Tried many times and many variations but 109 SEEMS less then what it was.