RE: Re: Unable to open a file

From: Don DeLoach <ddeloach_at_comcast.net>
Date: Tue, 28 Feb 2012 09:58:15 -0700

Having used the McCombs formulae for years I can tell you this doesn't much
matter in the practical sense. The resulting starting CG postions are always
very close to optimum regardless of whether you measure the tail moment from
LE to LE, quarter chord to quarter chord or CG to quarter chord.

 

Then again McCombs was not concerned with indoor duration and their
extremely aft CGs. He devised his formulae to address indoor and outdoor FF
scale and outdoor duration, mainly.

 

Don DeLoach

Mentee of McCombs since 1985

 

  _____

From: Indoor_Construction_at_yahoogroups.com
[mailto:Indoor_Construction_at_yahoogroups.com] On Behalf Of John Barker
Sent: Tuesday, February 28, 2012 3:50 AM
To: Indoor_Construction_at_yahoogroups.com
Subject: Re: [Indoor_Construction] Re: Unable to open a file

 

  

The Tail Volume PDF is a sub section of the first file section headed
'Apparatus, charts, jigs, formulae...'.

 

I am surprised to see that Bill McCombs, who is usually reliable, has the
Moment Arm definition completely wrong. He states it as from the LE of the
wing to the LE of the Stabilizer when it should be from the Centre of
Gravity to the quarter chord of the stabilizer.

 

John
Received on Tue Feb 28 2012 - 08:58:17 CET