Flutter and Flap SB

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From: Angier M. Ames <alphadog [at] nii.net>
Subject: Flutter and Flap SB
Date: Mon, 07 Sep 1998 22:12:41 -0400
To: Lancair <lancair.list [at] olsusa.com>

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This message was originally sent to the LIST on August 24 and I am quite

surprised that it did not generate a single response except a personal one to

me from Lance Neibauer.







Check out the flutter data at Marv's website.



So, who are we to believe....Lance Neibauer or Martin Hollmann???



For the safety of my butt and that of my wife, I'll sacrifice a few pounds in

the baggage compartment and take Martin's suggestion of placing additional BID

on the top and bottom of the fuselage forward of the MKII tail.



In Lance's November '97 response to Martin's analysis of the MKII tail, he

indicated that a Service Bulletin would be forthcoming quickly concerning flap

pre-loading of about 4lbs at the outboard end of each flap.



Either I have missed this SB or it was never issued. Could one of you shed

some light on this subject?



I don't recall any discussion on this thread of the MKII tail flutter

controversy...so, any thoughts would be appreciated.



Angier Ames



Response....



Dear Angier,

I read your flutter comment and would like to add a few points.  First of

all, your concern is of obvious importance as it should be.  To that point,

please understand that the flutter issue was never between me and Martin.

We hired the absolute best flutter expert in the world for this type of

composite GA aircraft.  He has performed work during the past 20 years for

Grob, Extra, Dimona, Pilatus, etc., etc, etc.  The testing was far more

involved vs. what Martin did.  The result was acknowledgement of a flutter

free condition with the large tail, (with and without wingtip extensions),

up to 350kts.  I'm sorry and no disrespect meant to Martin who is trying to

learn this type of analysis, but he is in error - which is not the first

time by the way.  So, based on the freedoms of this experimental category,

you certainly are able to add weight to the tail section if it makes you

sleep better.   By the way, if this were a certified Lancair (Columbia) you

would not be allowed to do so.  However, if you do make those changes,

those possessing the greatest knowledge would tell you that you've merely

reduced payload and shifted CG aft - two very undesirable conditions.  Food

for thought.

Sincerely,

Lance