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From: "John Slade" <sladerj@bellsouth.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: IAS and Vne! Whoa!
Date: Tue, 4 Jan 2005 23:38:00 -0500
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> IAS is a pretty good indicator of the amount of force acting on the
airframe.
That's the way I understood it. The main issue for most of us with VNE is
the potential for flutter, and catastrophic failure of control surfaces.
However, I've read that at high TAS there's another nasty little demon
lurking called "Mach Tuck". The problem is well named, since it can cause an
unrecoverable dive where the "tucked" part can be the wings :(.
I believe Mach tuck is more related to TAS.

Here's a quote from someone who "seems to know what he's talking about"
borrowed from another list.....

"Mach tuck is an interesting phenomenon, basically it is the result of the
CL moving back as speed increases, increasing the twisting moment of the
main wing to the point where it overrides the horizontal stabilizers' (or
canards') capability to counteract it causing the nose to suddenly pitch
forward, and in extreme cases twisting the wings off the aircraft
altogether."

I'd love to where these nasty little buggars live, so I can avoid the
neighborhood. Unfortunately without destructive wind tunnel testing we don't
know where they are till we find them, then we don't get much of a chance to
document it. :(

Anyone know more?

John