Sender: <marv@lancaironline.net> (Marvin Kaye)
To: lml
Date: Wed, 24 Sep 2003 14:13:14 -0400
Message-ID: <redirect-2601921@logan.com>
From: "Eric M. Jones" <emjones@charter.net>
References: <list-2600187@logan.com>
Subject: Re: [LML] Gain a couple of knots
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About the only difference in basic aircraft configuration since Bleriot's
1909 "Antoinette" is that the horizontal stabilizer has changed from a
positive to a negative airfoil. The reason for this change was to eliminate
a horrible kind of control loss where the stab lost lift and thus rotated
the nose up, which stalled the tail...you get the picture. The tail now
being a negative airfoil, when losing "anti-lift" will rotate the nose down
and try to increase the airplanes airspeed. Canards of course, (positive
airfoils) use this effect to their advantage.

I think of this when I see Lancair race results and note the small
difference between the winners. Every taped seam and aerodynamic tweak
helps---so here's one--- Since the less "anti-lift" the tail has to provide,
the less drag it produces; load the airplane CG as far as possible towards
the tail, and think about a way to provide this rearward CG after attaining
cruise flight. I am putting a few gallon reserve fuel tank in its own little
compartment in the tail.

Big planes know this, they use the tail for fuel. Can some racers and/or
airline pilots opine on this?

(Be Careful--Don't rear-CG load taildraggers!)

Thanks,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones@charter.net