Bill Daniels wrote:
Just idle fun speculation, of course. Clearly, a conventional rudder like
the Genesis wouldn't work with a 31 meter span. But, it would take only a
tiny amount of drag at the wing tip acting through a 15 meter moment arm to
produce huge yaw moments. I've run this calculation a few times and the net
drag of tip drag rudders would acutally be less than a conventional rudder.
A trailing edge elevator would work fine regardless of the span. The
Genesis "T" tail is actually a hinderance.

Now a portion of the wing is not working at the optimum flap setting. I
think that the drag would be significant. The Genesis optimization
problem is quite different, as is a conventional Standard Class glider
optimization compared to a 15 Meter class glider. Note how different the
wing designs tend to be for Standard vs 15 Meter gliders (generally
lower aspect ratio/larger area for the Standard class).


As for the control moments to control engine thrust and "P" factors, yes,
that is a challenge. A few prople have suggested lowering the thrust line
so it passes through the CG and aerodynamic center. The rear propeler could
fold back somewhat like a Carat and be pulled into a tube in the rear
fuselage. Not sure how the landing gear would work with a low thrust line.

Perhaps using a jet would make the problem much easier; at least, the
thrust could be closer to the center line.

--
Eric Greenwell - Washington State, USA
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