"Chris W" wrote in message
news:a9T9d.5690$cJ3.3838@fed1read06...
Gary Drescher wrote:

Minor correction: the wings snap due to excessive lift (force), not due
to excessive Gs (acceleration).

What?!!! You can't have force with out acceleration and you can't have
acceleration with out force. The most basic formula in physics is:
F = MA or Force = Mass times Acceleration. A net force gives you
acceleration.

Yes, of course. But staying below Vno is what keeps the wings from snapping,
by keeping the lift (force) from being more than the wing can bear. Staying
below Va is what keeps the aircraft's acceleration from being more than
other components can bear.

The difference is important, because it explains why you have to scale Va
(but not Vno) in proportion to the square root of your gross weight. For a
given airspeed, weighing less obviously does not put greater lift force on
the wings. But (again for a given airspeed), weighing less does increase the
acceleration that the lift force causes (F=MA; for a given airspeed, lift=F
is constant; so less M implies more A). That's why Va becomes a stricter
limit at lower weight, whereas Vno is unchanged.

--Gary