I don't know much about aircraft certification and airframe limits, though I do recall that new airframes are often tested in steep dives in excess of Vmo, to determine the maximum dive speed Vd? If you could find the figures for Vmo and Vd for a given aircraft that would go a ways to answer your question, as obviously the test pilots did not experience any loss of control up to this speed.
Thank you for your reply mig3.
Yes, I understand.
It is the classic V-G flight envelope.
But what I'm asking here, is the opinions from experts based on experience.
So far we have un-commanded changes to the fundamentals of flight based on Capt Claret, at 30 knots over Vmo.
411A claims L1011 crews experienced no changes at 30 knots over Vmo.
All I am doing here is to find out expert opinion of those who have time in their aircraft and when they THINK (based on their experience in their aircraft), they would lose control over Vmo.
I am in no way asking anyone to try it, or admit they have. Just opinion only.