Aileron Reversal
 

I don't have a copy to hand, but Jeffrey Quill's fascinating book "Spitfire" describes the problem of aileron reversal being met on some marks of Spitfire, causing significant torsional stiffening of the wings to be required.

I've met one modernish light aeroplane (the CFM Shadow) which depending upon model can do this in a big way also.

However, can anybody refer me to any other aeroplanes that have had aileron reversal problems - ancient or modern?

G

Hellcat, I think, maybe.

At above 345 KIAS, the VC10 suffers partial aileron reversal. Thus symmetric spoiler extension as speedbrakes is inhibited above that speed to ensure that the spoilers can be used differentially for roll control.

Not usually a problem nowadays as Vmo has been reduced to 300KIAS....

P-47 Thunderbolt as I recall.

Think the Bearcat did as well.

Lear 23/24/25 during over Mach limit, usually followed by wing separation.

McDonnell F3H Demon was one. Also had a bit of a problem with drop tanks. There was so much drag, that the aircraft range was reduced to less than a clean one :}

Conan

Believe the FW-190 suffered from it too - read somewhere that only thing that kept some Hurricane pilots alive was a low level turn at the last minute.

Conan: "Also had a bit of a problem with drop tanks. There was so much drag, that the aircraft range was reduced to less than a clean one "
Guess you needed to have enough of them and the money for new ones to be able to actually drop them . Not too practical in peace time I suppose.:)

A lot of big Boeings. For example, the B747 has inboard and outboard ailerons to counter the problem. The outboards are only used at slower speeds, the inboards, because of their position cause very little torsion twisting so don't lead to aileron reversal. The Classic 747s outboards are used when the flaps are at 1 or more, the 747-400s are speed scheduled. 237 Knots rings a bell.

The 707 and 727 had inboards as well. Don't think the 737 does, and don't know about the 777. Airbusses don't.

Aileron reversal
 

If my fading memory serves me the crash of an RAF Argosy during a high speed low level run at El Adem ? was put down to either wing warping and/or airleron reversal. I believe the Argosy utilised the Avro Shackleton wing with minor mods, and thus not optimsed for speed.

Page 131 of NACA Report 868, Summary of Lateral-Control Research:
For the P-41C-1-RE at 400 mph IAS, a 31% loss in aileron effectiveness. The aileron reversal speed is about 545 mph IAS.
Spitfire at 400 mph IAS, approx 65% loss in aileron effectiveness.
Get it at http://techreports.larc.nasa.gov/

Not sure if the F-100 actually suffered from it, or was designed from the start with inboard ailerons?

Now here's an interesting situation....

A320 Captains Side stick works in the opposite sense to the Co-Pilots... Read on:

http://www.cs.york.ac.uk/hise/safety...2001/0362.html

Rgds BEX

Ancientaviator62

Is that the one that hit the water tower ?

Genghis,

It was only the very last marks - Griffon engined marks 21 and above - that were affected.

The torsional stiffness of the wings on the mark 21, 22 & 24 was increased by 47% over previous marks, raising the theoretical aileron reversal limit from 580 to 825 mph IAS.

Up to this point, aileron reversal had not been considered a problem, as the vne was lower than the theoretical AR speed for other reasons. But with the advent of ever more powerful engines, the designers felt that the margin was decreasing too rapidly between the attainable speed in normal operating conditions and the AR limit.

Apparently the Bristol Bagshot experienced the phenomenon in 1927, also the Lockheed C141 (somewhat later, obviously). The Mig. 29 had small vortex generators added each side of the nose to overcome an early tendency to aileron reversal at angles of attack above 25 degrees.

Tim, the F-100 problems were legendary. Aileron reversal, Yaw coupling - take your pick. A very hard and painful lesson accelerated by the Korean war, but eventually they got it about right. Even the experienced, hardcore Sled drivers referred to a good landing, as a controlled (and flapless) crash.

The author of Jonathan Seagull, Richard Bach (and many other priceless tomes for those with a love of aviation - wonderful author) was an ex Sled jockey and I seem to remember him writing a superb piece about it.

Might start a thread on Richard Bach one day.... Inspirational...

Conan

Saab Dastard - do you mean 'aileron reversal' or 'roll reversal'?

At high AoA, the F-4 Phantom suffered hugely from roll reversal if the control column was used to roll the a/c. So much so that the phrase "If it buffets, use your boots" was often heard. I recall quite clearly the 'High AoA' handling trip I had to do with the Sqn QFI - including a 360 deg 'rudder roll' maintaining 19(??) units AoA...

Nothing to do with wing stiffness, this was purely an aerodynamic blanking effect. The F-4 used aielron and spoiler to roll; at high AoA the adverse yaw from the downgoing aileron was considerable and the upgoing spolier was blanked from the airflow...

Modern FBW takes care of such unpleasant quirks, leading to 'carefree handling' throughout the flight envelope which would have been totally impossible in older jets such as the F-4.

aileron reversal
 

Sled dog I believe it was.

In May 1968, XR133, the Whistling Tit to which you refer, hit a 45 gallon oil drum mounted on a wooden support 10 ft off the ground at Gat-el-Afrag desert strip in Libya during a low level high speed beat-up, euphemistically termed an 'undercarriage check'....:rolleyes:

In the collision, the a/c was in a right hand bank and lost the outer section of the starboard wing and the starboard aileron. Attempting to roll to port when the left wing is producing considerably more lift than the right could, I suppose be thought of as 'aileron reversal'...:uhoh:

However, the root cause of the accident was pretty obviously something else.