P-51 snap roll

[Pelican]

I'm sure many of you have noticed that as the P-51 approaches its stall speed it rolls over rapidly (snap roll).

 

Going on a hunch here....does the engine torque cause this effect as rudder authority is limited due to low airspeed?

 

:huh:

[Capn kamikaze]

You could test it, keep the governor and MP low and see if it still does it.

[Pelican]

You could test it' date=' keep the governor and MP low and see if it still does it.[/quote']

Cheers :) I'll try that....

[Cykyrios]

A snap roll is actually caused by a wing stalling before the other one does. I do believe though, that torque from the engine makes it easier to roll one way (to the left IIRC).

I also think the effect is noticeable at higher speeds, where your snap roll will be faster to the left than it will be to the right (again, IIRC).

[Pelican]

A snap roll is actually caused by a wing stalling before the other one does. I do believe though, that torque from the engine makes it easier to roll one way (to the left IIRC).

I also think the effect is noticeable at higher speeds, where your snap roll will be faster to the left than it will be to the right (again, IIRC).

 

Thanks...that makes a lot more sense now :)

[Harpoon]

By my uneducated understanding of physics, the wing on the lower side will snap first because of the center of gravity pulling slightly to the lower side as that wing dips closer to Earth.

[westr]

I believe pulling the stick back hard and inducing rudder causing a snap roll was a manoeuvre used by some P-51 Pilots during WW2 to get out of trouble.

[Ala13_ManOWar]

I'm sure many of you have noticed that as the P-51 approaches its stall speed it rolls over rapidly (snap roll).

 

Going on a hunch here....does the engine torque cause this effect as rudder authority is limited due to low airspeed?

I haven't notice as I don't let P-51 to go so low speed first :D, but engine stalls makes aircraft to drop a wing, and yes that's because engine torque. Try stalling with idle engine, you'll see how mild stalls are. That two points are stated in P-51 handbooks.

 

 

Also, snap roll is an aerobatic manoeuvre and has nothing to do with engine stalls. A snap roll is a prohibited aerobatic manoeuvre for P-51 (but you can try in DCS as you don't pay the bills :smartass:) where you stall aircraft intentionally while in flight by suddenly pulling full stick back while kicking one pedal at the very same time, one wing stalls violently so a real "snap roll" is produced. Stopping roll at the time you desire (say fully horizontal again) is a really hard to master thing aerobatic pilots has to work. You have to fly at the right speed or it won't work at all even pulling/kicking controls.

 

 

Here, first manoeuvre, 0:12, that's a snap roll,

 

 

 

 

S!

Edited March 12, 2016 by Ala13_ManOWar

[Anatoli-Kagari9]

I read somewhere that the tail fin added to later models of the p51, designed to overcome some yaw instability problems, also made snap-rolls a lot more difficult to execute.

 

Anyway, due to it's considerable inertia, a snap-roll in the p51 will certainly necver look like that one in the Extra 300 - one of the only reasons I really liked to play Aerofly FS :-)

[ivo]

watch here: [ame]

[/ame]

[Pelican]

Thanks everyone....that makes it a lot more clear now :)

[Ala13_ManOWar]

Yep, I've use it many times in the old Il-2 years. Some times it can save you, but also you kill your energy completely so it's an absolute last resource manoeuvre. In DCS with a highly detailed FM as we have and how energy management works I don't think is any good in combat.

 

In my squad we called it "the drunken monkey" :lol:.

 

S!