Really pushing the envelope

In the book "The Wrong Stuff", the test-pilot and author recounts flight
testing during the 50's.

In one case they were instructed to test how much stress the tail could
take.
To get enough stress they had to do a rather steep dive and level off at
some very low altitude (to get enough air load).
Several planes and pilots were lost when unanticipated flutter set in. They
had parachutes but popping out at those indicated air speeds and altitudes
are mighty iffy.


How's this done nowadays? I can't imagine the pilots are that eager to run
these tests during relative-peacetime.

Regards,


George