On Tue, 26 Jun 2007 14:28:14 -0700, Dancing Fingers
wrote:

Hi Guys,
I remember years ago Kitplanes did a series on the potential for
batterry-powered aircraft. Recently, I watCHED Future Cars on the
Discovery channel and this guy had developed a car that ran on
compressed air. This seems like a more viable fuel for aircraft then
batteries. Has anybody looked into it?

No matter how you describe it compressed air is not a fuel although it
can be used as a source of stored energy which is quite different. The
amount of energy you could store in compressed air is a tiny fraction
of what you can get from conventional, or even bio fuels. I doubt you
could build a 4 passenger plane capable of making it around the
pattern on compressed air let alone any thing larger. It takes a lot
of energy to compress the air and then you only get a portion of that
back. It's probably one of the most inefficient and energy hungry
systems tried.

Battery technology is making some tremendous strides in current
density, but they are heavy, dangerous, (The higher the current
density the more dangerous) and a problem when it comes time to
dispose of them. Even at their best they have only worked on very
light experimental aircraft and although they carry much more energy
than compressed air is capable of doing, they are still far inferior
to conventional fuel.


just curious.
Chris