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Old September 10th 09, 03:27 PM posted to rec.aviation.soaring
Frank Whiteley
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Default Double Release Failure

On Sep 10, 2:37*am, (Alan) wrote:
In article Jim Beckman writes:
At 14:13 08 September 2009, FBCompton wrote:


Important Timing Aspect: *The glider (in low tow) must not touch down
much before the towplane -- this can be a hazardous aspect -- touching
down well before the towplane and stalling it. *The glider wings are
still carrying the weight of the glider while it is flying. *Once the
glider touches the wings stop lifting and the glider creates more
weight drag on the towplane, which if still well above the runway will
be slowed and may stall. *


This seems counterintuitive to me. *When the wings stop lifting, the
induced drag goes away, so the drag on the towplane should decrease. *The
only added drag is friction in the glider's main gear. *What am I missing
here?


Jim Beckman


* It seems backwards to me, too, but I have asked tow pilots about this,
and I was told that they feel the drag decrease when the glider comes off
the ground on the takeoff roll.

* I guess those wheels have a lot of drag.

* * * * Alan


Behind less powerful tow planes, I generally note a 3-5 knot jump in
airspeed immediately following glider lift off.

Frank Whiteley