Doug wrote:
Alcohol would work just fine in GA aircraft, as well as in
cars. Very few problems at all, once the engine and fuel system is
fully designed for it.

I've been reading a bit about what Ford had to do to get the Escape to
run on E85 (85% EtOH, 15% gasoline). One of the issues was the fuel
pump. E85 is electrically conductive (gasoline is not), which was a
problem for the pumps they were using. I don't know how that carries
over to airplane fuel pumps, or what it was about the pump in the
Escape which cared that it was pumping a conductive fluid.

I don't know how EtOH compares to gasoline for available energy per
pound of fuel, which is sort of an important issue for airplanes.