From: RWolf99@aol.com
Message-ID: <1a36ba3f.36a18342@aol.com>
Date: Sun, 17 Jan 1999 01:29:22 EST
To: lancair.list@olsusa.com
Subject: Flutter Modification
Mime-Version: 1.0

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Thanks for the comments.  I will look forward to Marv's response from Martin.
I won't do anything until then.

There was a suggestion that Martin was somewhat irresponsible in his comments.
I hope I did not give that impression as nothing could be farther from the
truth.  When telling me that the flutter mod could be stopped at the bulkhead
and restarted on the other side he was clear and unambiguous that it was
acceptable.  For my other suggestion (filling the trough instead of using the
18 + 12 + 8 inch layers) he was adamant that I was on my own here.  His
feeling that it should be all right was only that, the educated estimate of an
expert whose initial reaction was affirmative, but he was quite clear that
there was no analysis to support this opinion and I was on my own.  "The
analysis wasn't done that way" were his words.  I'm an engineer -- I know what
that means.  Sorry about any confusion.

I should point out that I have a lot of respect for Martin's approach and less
confidence in Lance's steadfast denial of the flutter potential.  When I flew
stuff on the Space Shuttle, NASA was quite clear that tests are to used to
verify analyses.  Martin did state-of-the-art analysis and validated it with
testing.  The validated model showed the flutter potential, which could be
discerned from test data if you knew where to look but was not a striking
feature of the data.  Lancair did testing, which was good, but did not appear
to have an analytical model to check it against.  This is why they don't
believe it's there.

In point of fact, not a single 320 Mk II has fallen out of the sky from
flutter and that's a pretty strong indication that the plane is basically
safe.  But I wouldn't want to be the first (or even the second) one to hit
that freak flight condition that triggers it.  I'm putting the mod in but I'd
like to use the trough technique if possible. 

- Rob Wolf