Tandem-wing Airplanes

"Phil J" wrote in message
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OK. But why on the canards flying these days is the little wing in
front of the CG, and the big wing behind it. It seems like it would
be more stable in pitch if the little wing was behind the CG. Putting
the little wing in front of the CG seems like it would make the
airplane inherently unstable in pitch. Looking at Rutan's designs, it
looks like he countered this by using a swept main wing. But that
would have been unnecessary if he had put the smaller wing in back.
The only reason I can think of to put the smaller wing out front would
be for pilot visibility, so maybe that's the explanation?

Phil

The pitch and yaw stability of an aircraft have to do with the relationship
of the center of gravity and the center of pressure. The farther ahead of
the CP the CG is, the more stable an aircraft will be.

The swept wing on rutan designs serves 2 purposes. First, it moves the
center of lift (and center of pressure) aft in order to accomodate the aft
CG caused by the rear mounted engine. Second, sweeping the wing places the
vertical surfaces farther aft, giving them more authority.

KB