Inflatable Rotors (Flying Car?)

Seriously though, a helicopter has an extremely small wing area compared to an
equivalant fixed-wing aircraft, and therefore has a tremendous wing loading
The type of loading that would rip the wings off a GA airplane. The reason it
works on helicopters is because of rotor speed and cintrifugal (sp?) force. A
relatively high rotor speed (speed of the rotor blades through the air nearing
the sound barrier) creates a great deal of lift per square foot. However,
because the rotor blades are spinning, cintrifugal force puts the blades under
tremendous tension. This holds the blades in a relatively level plane and
keeps them from flexing upwards excesively and breaking off.

While more blade area can be traded for lower rotor speeds (Hughes built one
with a rotor speed of 16 RPM), you cannot ignore the necessity of cintrifugal
force. A group of students from MIT tried to build a human powered helicopter
a few years ago. They used a 2-blade 60" chord 100+ foot disk setup with
extremely low rotor speeds. While the blades made plenty of lift, the students
could not make them strong enough for the given weight to keep them from either
coning upwards or breaking off. The same would be true of inflatable blades.

Harry