Yes John: "Overall, the limit's application is that the pilot should be able to
(a) apply a rapid steady input in any ONE control to the stop ie NOT significant inputs in multiple controls simultaneously.
(b) rapid control input reversals and intentional pilot input oscillations are not included in the design considerations .. ie if you are at Va (or somewhat below) and start pushing and pulling on whichever control is limiting .. you might get an unpleasant (and, potentially, fatal) surprise. A read of the accident report on AA 587 is illuminating."
After that accident, the FAA eventually produced Special Airworthiness Information Bulletin CE-11-17 - every pilot must read this:
http://www.safepilots.org/documents/...ring_Speed.pdf
There is an excellent description at
The Risks of Maneuvering Speed Myths - AVweb Features Article
One often sees simple statements such as:
“The maximum speed at which the limit load can be imposed (either by gusts or full deflection of the control surfaces) without causing structural damage.”
“Maneuvering Speed is the maximum speed at which you may use abrupt control travel.”
Aerobatic pilots should be familiar with the definition provided by CASA in their CAAP 155-1, Aerobatics, which states:
“Manoeuvring speed (VA) is the speed above which full deflection of the elevator control will exceed aircraft structural limitations. Below VA the aircraft will stall before structural limits can be exceeded.”
Question: an aerobatic aircraft with the usual G limits of +6 and -3, flying straight and level at Va - can the pilot abruptly move the control stick fully forward without exceeding structural limitations?
All are woefully inadequate definitions of VA and it is particularly disappointing to see that CASA’s advice to aerobatic pilots is also inadequate.
For engineers, sorry John but ...
"The basic idea of Va is looking at loads in the pitching plane. For this case, Va is the speed at which the limit design load factor occurs at the stall speed for that weight." Nope.
That SAIB with its statement about that accident was all about the rudder. Aileron application is also very important and, related, rolling Gs.
Don't forget the ifs and buts in various versions of FAR 23. Remember that Va need not exceed Vc and Vc need not exceed 0.9Vh. And the Va in the regs is Vamin - the designer may select a higher Va. i.e. Va may not be that corner speed - newer versions of FAR 23 fixed this I believe.