Off-topic, but related. There once was a four-jet
called Valiant, and a wood-trained iron pilot who flew
them. He had an ingrained habit, after landing and
shutting down, of getting a stepladder and climbing
it to grab and shake the wingtip. Everyone laughed,
until the day his wingtip didn't shake [it never shook
much] but came down limply a couple of feet in his
hands. Next morning the entire fleet of 150 or so
aircraft was grounded, and most of them never flew
again...

Ian







At 22:48 18 February 2006, Jcarlyle wrote:

Initially I thought the wing oscillation rate had something
to do with
flutter prevention or attachment integrity. When I
was being taught how
to preflight the instructor told me he once found a
wing that wasn't
properly attached by shaking a tip.

If wing frequency was being used for wing structural
integrity testing
years ago, I'm glad to hear that it's been abandoned!
Flaws that can
cause structural failure are much too small to affect
a fundamental
resonant frequency.