P-51 Torque Roll

[supercub]

I'm not going to mention any names......but a well known warbird/ex race pilot was talking to a friend of mine a few days ago about the recent accident in Southern Ca involving a P-51. I believe the initial NTSB report and general consensus is the accident was caused by a sudden increase in power, resulting in a torque roll. My friend said this experienced P-51 pilot that he was talking with.......said this was basically a myth.......that there is sufficient rudder and aileron control to keep the airplane going straight. This is in opposition to what I've always read and heard, in fact, if memory serves me, in the recent AOPA magazine, Barry Schiff talks about using no more then I believe it's 45" MP on a go around, but not having ever flown a Mustang I'm certainly no expert. Would like to hear from anyone with experience in Mustangs. Years ago, I did witness a Mustang that was attempting a wheel landing, he began to porpoise so applied power......the airplane started to yaw and roll left.......the pilot reduced power and leveled the wings and then slowly came back up on power.

[AAFO_WSagar]

Re: P-51 Torque Roll

I'm not a legally licensed pilot of any airplane, certainly never flown anything like a Mustang but I have heard this fact over and over from so many sources, and over the past 40 years, I've read it in MANY books.. it's not a myth. There is more power/torque in those old radials and in-line propeller airplanes than there is control authority at low airspeeds...

Wayne

[Bottom Rudder]

Re: P-51 Torque Roll

It is certainly no myth. 30 to 45 inches of manifold pressure and around 2,700 rpm is a good place to start a go-around. This allows easier control of the aircraft while you get it cleaned up and climbing.

Your right leg and foot will certainly know what is going on. A little right aileron won't hurt.

Done properly, it's very manageable. Very sorry to lose a good man at Camarillo.

[stuntflyr]

Re: P-51 Torque Roll

I'm not going to mention any names......but a well known warbird/ex race pilot was talking to a friend of mine a few days ago about the recent accident in Southern Ca involving a P-51. I believe the initial NTSB report and general consensus is the accident was caused by a sudden increase in power, resulting in a torque roll. My friend said this experienced P-51 pilot that he was talking with.......said this was basically a myth.......that there is sufficient rudder and aileron control to keep the airplane going straight. This is in opposition to what I've always read and heard, in fact, if memory serves me, in the recent AOPA magazine, Barry Schiff talks about using no more then I believe it's 45" MP on a go around, but not having ever flown a Mustang I'm certainly no expert. Would like to hear from anyone with experience in Mustangs. Years ago, I did witness a Mustang that was attempting a wheel landing, he began to porpoise so applied power......the airplane started to yaw and roll left.......the pilot reduced power and leveled the wings and then slowly came back up on power.

Hi Supercub,

The difference in opinion comes from the definition of "torque roll", and the real reason that the airplane changes direction in three axis during high power, low airspeed conditions.

There is an excellent article about this in AvWeb's Pelican's Perch by John Deacon. John explains the whole process as well as I, or most anyone, can. Check it out.

It seems that every decade or so a spate of accidents happen that makes one think all of the previous knowledge has been lost. It hasn't, but the proliferation of knowledge about the basics needs to continue.

I might ad that not all students are predictable, either.

In about 1968 Mike Dillon wrote a fine article in Air Progress, the exact title I can't recall, but the dramatized 10 year old paraphrasing was "Fly Your Own Fighter Plane, or Death in a Beautiful Package" or thereabouts, which was about the four basic forces at work on high powered fighters at high power and low airspeed. It is still a great one and should be a must read for all those flying any airplane, tailwheel or tricycle, high power or low.

Supercub, if you are a Super Cub pilot, you know what the rudder does in climb. Try an experiment. Hold the stick and rudder in one position for a 60 mph cruise. Then push the throttle all the way up and see where the nose goes.
The Mustang, Sea Fury, Bearcat, Hellcat, P-40, whatever,
does the exact same thing and the same control inputs make it go where you want it to go.

One thing not spoken much of is the control pressures required to get the control surfaces to the position to do the most good. 100 lbs or more are required if the trim tabs are in certain positions. The pressures can be so high that the controls cannot be moved to where they need to be to correct the attitude of the airplane.

For little airplane drivers try this; a trimmed out, flaps 40, 60 mph glide in an older Cessna 182. Then push the throttle to the stop and see how much elevator force it takes to hold the same attitude. This would be a primer for an out of trim condition in a warbird.
For those with light twin time, remember the rudder pressures that you trim out after the "drill". Remember the rudder forces that suddenly appear when you retard the good throttle in the flare? There are many examples that might be a sample of the control pressures required of a pilot of a warbird.

(According to my good buddy warbird/race pilot, the short fuselage P-40 is the worst rudder pressure hog during a go around.)

You ask a good question. As well, your buddies warbird/race pilot is right. But, he has simplified the situation to make it difficult for the general public to properly understand the details.

Chris...

[Apteryx]

Re: P-51 Torque Roll

Here's the Deakin, AVweb article: http://www.avweb.com/news/pelican/pe..._195755-1.html
He's a little wordy, and I'm not happy with him naming the instructor, (I had not seen that in print elsewhere), but it's an interesting read.

Paul

[Race#21]

Re: P-51 Torque Roll

Torque roll is a reality. Three point (full stall) landings in any tail wheel aircraft denies the pilot of most if not all available control surface authority. Full stall, tail wheel first landing, and civilian flight training go-around procedures ("peddle to the metal") power application in high performance military aircraft = very bad things.

[Apteryx]

Re: P-51 Torque Roll

The Brown racer Miss Los Angeles, did a dramatic demonstration of a torque roll, to an inverted landing (pilot ok), a while back. So it's not just a problem of brute power.

Paul

[Randy Haskin]

Re: P-51 Torque Roll

He's a little wordy, and I'm not happy with him naming the instructor, (I had not seen that in print elsewhere)

Are you kidding? I read that Jackson was the instructor the first day after the accident -- it was no secret.

Besides, I think it's completely relevant to identify the instructor as one who is highly experienced and competent -- it removes the "what if the instructor was a total idiot and taught the student incorrectly" part from the equasion.

[stuntflyr]

Re: P-51 Torque Roll

Well Randy,

Paul says the Deacon article was too wordy and the Miss Los Angeles accident was another "torque roll", too!
I think he is a very funny guy...just kiddin' us.

I didn't know Matt had a CFI...

Chris...

[John H]

Re: P-51 Torque Roll

I think we've just had two accidents caused by torque rolll......wasn't Oshkosh as well?

John

[MRussell]

Re: P-51 Torque Roll

I think we've just had two accidents caused by torque rolll......wasn't Oshkosh as well?

John

Absolutely not.

[Apteryx]

Re: P-51 Torque Roll

Besides, I think it's completely relevant to identify the instructor as one who is highly experienced and competent -- it removes the "what if the instructor was a total idiot and taught the student incorrectly" part from the equasion.

You're probably right, I like Matt, and I just hate to see the speculation that the regular press usually brings.

[AirDOGGe]

Re: P-51 Torque Roll

I'm not a legally licensed pilot of any airplane, certainly never flown anything like a Mustang but I have heard this fact over and over from so many sources, and over the past 40 years, I've read it in MANY books.. it's not a myth. There is more power/torque in those old radials and in-line propeller airplanes than there is control authority at low airspeeds...

Wayne

Agreed. The last place I recall reading it was in Pappy Boyington's BLACKSHEEP book, when he described a newbie rolling one of the "new" corsairs by applying full throttle during a slow landing to go around (he survived, but the plane didn't).

Let's face it, aerodynamic surfaces need lots of air flowing over them to function properly. If the airflow is miimal over the wings, roll control is reduced. If high power is then added with sufficent blade pitch, then that huge prop out in front becomes boss, and the engine assumes roll authority

I've experienced it in RC, when I stuck a .40 size motor with an 11" propeller on a biplane that was intended for a .25 with a 9.5" prop so I could get it off a rough field. I was a rookie with tail draggers at the time too.

Upon first take-off (full power, natch ) the plane accelerated like a bat on fire, both yaw'd and rolled to the left and took off in that direction, flying knife-edge at 3-4 feet altitude and slowly rolling over on it's back, despite my desperate full right aileron and rudder. I didn't think fast enough to let off on the throttle, and the event ended with a nasty cartwheel and a severely broken bird.

A warbird with thousands of horsepower, a huge propeller and slow airspeed, and you firewall it? Tighten your helmet and straps....You are going for a badddd ride.






.

[Jason S.]

Re: P-51 Torque Roll

Well Randy,

Paul says the Deacon article was too wordy and the Miss Los Angeles accident was another "torque roll", too!
I think he is a very funny guy...just kiddin' us.

I didn't know Matt had a CFI...

Chris...

As far as I know he is. He trained and signed off Tom Cruise for his Mustang.

[Peashooter]

Re: P-51 Torque Roll

I was just talking to a WW-II Mustang driver about this subject yesterday. (55th FG, Duxford based) Before there were any TP-51s availalbe, the instructor pilot would take the new -51 driver up in formation and would demo slow flight and power application as part of the training syllabus from a safe (high) altitude. He recalls 120 kts, flaps and gear down and throwing the throttle to it. Once, he got 2 and a half snaps out of it before there was sufficient airspeed and control authority to recover.