Avoiding Vne

Don

First - I agree entirely that you are contemplating which of two evils you
should perpetrate having got yourself into an untenable situation. But having
got there you need to at least have considered what you should do in the event.
I doubt there would be much time for deliberation.

I suggest that the correct action depends on the aircraft to some degree, but
that flutter is much more damaging to the structure than moderate overstress in
most cases since it introduces large cyclical and localised loads on the
structure in addition to whatever G load the aircraft is exposed to.

First generation glass, before the finite element analysis programs allowed the
designers to design to the limit is probably much safer to over stress than
overspeed. Similarly the latest carbon designs seem to have G limits imposed by
the JAR22 deflection limits rather than ultimate strength. Presumably these
aircraft have huge strength reserves. For interest look at the wing test on the
DG1000.

When I asked Schempp-hirth about the possibility of flutter damage in an
incident where a Std Cirrus had made a loud chattering noise on a high speed
pass, they replied that it would be unlikely to have been flutter. This because
they did not think it likely that the aircraft would remain controllable due to
control system damage in the event of flutter.

In inspection we found that the noise came from an airbrake cap that had lost
some tension in the retention springs. It was sucking slightly open and banging
against the sides of the slot as the pilot pulled up. Over one G, close to Vne
and soft springs combined to allow a millimeter or so of play. The noise was
disconcertingly loud from the ground, we thought there might be a glass-fibre
confetti shower.

I'd take a gamble on the Cirrus's wings handling more Gs than the manual said if
my life depended on it. Conversely I take great pains not to get even near that
point in a 32 year old glider.