25 is magic number

tongaloa wrote in :

Nathan Young wrote:
On Tue, 10 Feb 2004 15:21:50 -0500, tongaloa
wrote:


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


250kt cruise is really pushing it in a piston engined airplane. A 421
can max out at 250kts, but cruise will be more like 220-230kt. The
only exception might be a Lancair IV-P and this was posted to the
homebuilt newsgroup, so that's a thought.

Will have a look.
Aerostar does 250kt OK at 25000. TIO 540's.
Range is limited by 38-42GPH and gross - empty = 2000 lb.

Looking for single that can do the 250kt and max gross - empty = big
enough number for fuel plus 250lb.



http://www.youngeagles.org/15000pics/15035.html

Probably does not have the range though...

--
ET


"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

Lancair IV fitted with extra tanks in lieu of seating might work.

http://www.lancair-kits.com/Lancair_IV.html

Cruise 330mph (280kts)

Extended fuel option = 110 gallons
Range = 1550 sm = 1347 nm
fuel consumption = 18-22gph

So to make up the remaining 1200nm of range required, you need 4.3 hrs
of fuel or 94 more gallons. 94 gallons = 564 lbs

The Lancair has a 1500lb useful load, so subtracting the 204 gallons
(1224 lbs of fuel) = 276 lb of useful remaining. Just enough for the
250lbs pilot + gear.

-Nathan

Thanks you.
Just submitted some more resumes and purchased a lottery ticket ;-)
-bob


The Lancair has a 1500lb useful load, so subtracting the 204 gallons
(1224 lbs of fuel) = 276 lb of useful remaining. Just enough for the
250lbs pilot + gear.

-Nathan

Thats what I was thinking. He is asking for an especially long range
but also an especially small payload for that power of airplane. So
the real technology is how to fill up the plane with all that extra
fuel?

Internal wing tanks, more complex but puts the load where you want it,
so you aren't going to fold the wings up if you hit turbulence.

Diesel may be one technology to look at, already turbo for high alt,
and very fuel efficient. Have to need a lot of gas to justify the
lower power/weight ratio of the power-plant itself.

Another point to make is extended flight over water is usually done by
multi-engine aircraft for obvious reliability reasons. The Pacific
Ocean is a big place; I'm not sure how comfortable I'd feel with the
possibility of a single point failure in the most complex system in
the aircraft causing me to ditch.


tongaloa wrote in message ...
Thanks you.
Just submitted some more resumes and purchased a lottery ticket ;-)
-bob


The Lancair has a 1500lb useful load, so subtracting the 204 gallons
(1224 lbs of fuel) = 276 lb of useful remaining. Just enough for the
250lbs pilot + gear.

-Nathan