French aviators are fond of employing a carefully designed car for the
operator and control mechanism. The Wright designs practically ignore
the car: the aviator sits on the forward edge of the lower plane with
his legs hanging over.
It has been found that auxiliary planes must not be too close to the
main wings: a gap of a distance about 50% greater than the width of
the widest adjacent plane must be maintained if interference with the
supporting air currents is to be avoided. Main planes are now always
arched; auxiliary planes, not as universally. The concave under surface
of supporting wings has its analogy in the wing of the bird and had
long years since been applied in the parachute.
[Illustration: CARS AND FRAMEWORK]
The car (if used) and all parts of the framework should be of "wind
splitter" construction, if useless resistance is to be avoided. The
ribs and braces of the frame are of course stronger, weight for weight,
in this shape, since a narrow deep beam is always relatively stronger
than one of square or round section. Excessive frictional resistance is
to be avoided by using a smoothly finished fabric for the wings, and
the method of attaching this fabric to the frame should be one that
keeps it as flat as possible at all joints.
[Illustration: SOME DETAILS]
The sketches give the novel details of some machines recently exhibited
at the Grand Central Palace in New York. The stabilizing planes were
invariably found in the rear, in all machines exhibited.