Rudder Used Only For Steering.
"When defendants' balancing surfaces are moved they
present equal angles of incidence to the normal rush
of air and equal resistances, at each side of the machine,
and there is therefore no tendency to turn around a
vertical axis as is the case of the machine of the patent,
consequently no reason or necessity for turning the vertical
rear rudder in defendants' machine to counteract any
such turning tendency. At any rate, whatever may be
the theories in regard to this matter, the fact is that
the operator of defendants' machine does not at any
time turn his vertical rudder to counteract any turning
tendency clue to the side balancing surfaces, but only
uses it to steer the machine the same as a boat is
steered."
