"Tony Cox" wrote in message
. net...

You'll find Va covered in the FAR's for part 23 certified
aircraft he-

http://www.access.gpo.gov/nara/cfr/c...4cfr23_00.html

The relevant sections are 23.335 (where you see that Va
can be *no less than* Vs*sqrt (load factor) -- which means
that _it can be greater than this_, and 23.423 where its
relationship to control surfaces is discussed.

Short answer: Va is defined in terms of what the *control
surfaces* can handle, not what the plane can handle.
However, Va must be sufficiently high to satisfy 23.335,
which means (oddly) that there is no regulatory requirement
that stops you from flying at Va without exceeding the load
factor. Well fancy that!.

Your points are excellent, but I think the issue is over terminology.

The "maneuvering speed" placarded in the cockpit is not Va. It is Vo. It is
defined by 23.1507 and the placard is mandated by 23.1563. "Vs is a
selected speed that is not *greater* than Vsvn". My *s. At or below Vo,
the criteria that are generally (and erroneously) thought to apply below Va,
do apply, i.e. the wing will stall before the positive limit maneuvering
load factor is exceeded.

Julian Scarfe