On Wed, 17 Mar 2004, tom ring wrote:

> Possibly true, but they don't scale to small size very well.  Turning the fuel
> directly to hot gas to spin the turbine is probably more efficient, and even
> more important, has a better power to weight ratio.  For instance, I haven't
> seen a lot of steam turbine prop aircraft.

You don't see a lot of water-cooled prop aircraft either. ;)  Aircraft
powerplants need high power to weight ratio.  This is more important than
any other factor, including fuel efficiency.  The thing about steam power
is it's HEAVY.  Not only do you have to carry around a boiler, you have to
carry around quite a bit of water and possibly a condenser as well.

David Brodbeck, N8SRE
'82 Volkswagen Diesel Westfalia
'86 Volvo 240DL wagon