Originally Posted by
peterh337
I'd say damage to flap mechanism, especially (on electric flaps) the actuator, is the most likely. But the answer must be hugely type dependent.
However if actual damage occured at 90kt when the flap limiting speed is 70, I would question the other design limits of that aircraft
At first approximation, aerodynamic loads go with the square of airspeed, and on an all-metal aeroplane the safety factor is 1.5.
So, if the flap limiting speed is 70, I'd expect most likely to start seeing some permanent damage at about 70 x (1.5^0.5) = 86 knots.
Sorry Peter, but actual damage at 90 from a limiting speed of 70 - is quite likely in any aeroplane designed to current regulations (by current, I mean anything since the late 1940s).
On the other hand, the flap limiting speed is usually around double the stall speed with full flaps: so a flap limiting speed of 70 implies a stall speed about 35, which probably makes it a microlight. Anybody capable of getting a microlight past 85knots, with the flaps down, should probably not be flying that or anything else unsupervised.
G