Received-SPF: none
 receiver=logan.com; client-ip=68.230.241.28; envelope-from=daveleonard@cox.net
From: "DaveLeonard" <daveleonard@cox.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: IAS and Vne! Whoa!
Date: Wed, 5 Jan 2005 06:43:44 -0800
Message-ID: <PIEMJLCHGPKMFMDHBKMLIENBCOAA.daveleonard@cox.net>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
In-Reply-To: <list-591911@logan.com>
Importance: Normal

Jim, I am sure you are right.  Flutter is mostly a function of the speed of
the air approaching some resonance frequency of the airframe and control
surfaces so that just as the airframe reacts to some perturbation the
control surface has moved in the opposite direction.  There will be a
minimal contribution from the density of the air (IAS) as it still needs to
have enough force to do it's bidding.  That density dependant factor will be
different for different airframes.  I don't know why we have not discussed
this before or that why I did not realize sooner that Vne was TAS dependant.

BTW - if it smells like I am pulling this out my A**, I am.  But I'll bet
you a case of beer that Jim is right.

Dave Leonard


>
> Actually, I've been given to understand that *both* IAS and TAS are a
> factor.  I don't know exactly what the relationship is, just that they
> both come into play.
> But now I've  told you more than I know ... Jim S.
>
> John Slade wrote:
>
> >  > Apparently Vne is NOT, it is a factor of True Airspeed!!
> > That's contrary to what I've read with respect to canard pushers, Ed.
> > As I understand it VNE for the Cozy, for example, is 220 mph IAS.
> > It's all to do with how many air molecules are hitting the airplane.
> > Someone tell me I'm wrong. ???
> >
> > John
> >
> >
> >
>
>
> >>  Homepage:  http://www.flyrotary.com/
> >>  Archive:   http://lancaironline.net/lists/flyrotary/List.html