"Peter Duniho" wrote in message
...

The definition of Va in Part 23 is clear. It has nothing to do with
control
surfaces and everything to do with stall speed and load factor.

Actually, it seems to depend on both. I'm all turned around
on this having scratched my head for a while. Greg is
essentially correct.

23.335 says that Va must be = Vs.sqrt(load-factor)
If we take the equality, then this is the load-factor
relationship we get assuming "Lift prop. to AOA"
and "Lift prop. airspeed**2".

23.423 (and others I'd missed) say how the control
surfaces must behave at Va and above. Designers
can set anything they want for Va as long as it
passes the control surface tests.

But since they are likely to want to minimize
complexity & weight of the control surface
mechanism, they are likely to choose Va to be
the minimum allowed by 23.335. But they don't
have to.

Greg is right. They really ought to have invented
another term for it. Va isn't the maneuvering
speed at all, and should be renamed to something
completely different.

--
Dr. Tony Cox
Citrus Controls Inc.
e-mail:
http://CitrusControls.com/