25 is magic number

rlier, tongaloa wrote:

mission requirements
250 kt cruise
2500 kt range
250 lb (pilot and 'stuff')
25,000 ft cruise altitude

The 2500 mile range is likely doable, after all, Lindbergh managed it
with 1927 technology. What he did was take an airplane and modify it
so that it was a flying gas tank. That required a number of
modifications to the original airframe to beef it up so it would hold
that much gas and not collaps when landing or clap the wings in
turbulence. He also had a gas tank in front of him such that it
totally blocked any view straight ahead. He compensated for that but
hanging his head out the open window. Not something I'd recommend at
25,000 feet. You've heard of the Voyager, Dick Rutan and Jeanna
Yeager flew it around the world with what they carried internally for
gas. That was a one off type airplane, and Burt Rutan has designed
another to duplicate the feat, this time jet powered and it will fly a
lot higher and faster than the Voyager.

The 25000 mile cruise altitude is of course obtainable, you just need
to size the wings accordingly and supercharge the engine somehow.
It's not new, it's done all the time by certified airframe
manufacturers. You'll need full time oxygen at that altitude, and a
lot of it if you are traveling 2,500 miles.

The big problem to me is the 250 kt cruise speed. There aren't many
singles that can manage that, those that do are running a pretty big
or they aren't big or both. Pretty big engines pulling an airplane
along at 250 kts don't get great milage, but perhaps that can be
compensated for by putting in enough fuel tanks. But then the wings
get larger and cost more drag and you have to beef up the airframe in
order to be safe and now you need more power to pull it through the
air. Tis a dilemma.

You are probably talking about a one-off type airplane. Maybe you
should speak with Mr. Rutan.

Corky Scott