Why are there no small turboprops?

Thomas,

There are some smaller turboprops but the economics just aren't there
to put them into mass production. The market is quite small and the
specific fuel consumption of a turbine versus a piston means that if
you put it on your Cessna 210, for example, you can't carry enough
fuel to get anywhere and still put people in the cabin. Plus, the
simple cost of the technology and the metals to handle the heat in a
turbine engine makes it almost impossible to compete with other types
of engines in that horsepower range.

There was an article on the subject of specific fuel consumption and
load carrying ability of turbines in little airplanes in Aviation
Consumer a couple of years back.

For the 100-300 hp range it looks as if going back to diesels, as was
explored in the 1930s, may be appropriate.

All the best,
Rick

"Thomas J. Paladino Jr." wrote in message .. .
I have always wondered why there are no small GA turboprops. It seems like
most of the major problems & maintenance issues associated with GA aircraft
are related to the piston motor, and as far as I can tell, turboprops are
much more reliable, fuel efficient, smoother running and easier to maintain.

So it begs the question, why are there no small turboprops in the 100-300hp
range for use on GA aircraft? I would think that turbine engines of this
size would be relatively easy to produce, and would be ideal for GA
applications. The smoother operation and lower vibration levels would also
ease wear and tear on the entire airframe and avionics components. So what's
the deal? Does turbine technology not translate downwards very well? Would
it be cost prohibitive? Am I entirely missing something?

(Rick Durden) wrote in message om...
Thomas,

There are some smaller turboprops but the economics just aren't there
to put them into mass production. The market is quite small and the
specific fuel consumption of a turbine versus a piston means that if
you put it on your Cessna 210, for example, you can't carry enough
fuel to get anywhere and still put people in the cabin. Plus, the
simple cost of the technology and the metals to handle the heat in a
turbine engine makes it almost impossible to compete with other types
of engines in that horsepower range.

Actually there is a turboprop conversion for the P210 called the Silver Eagle.
(see http://www.onaircraft.com). The stats look pretty good to me. Cruising
speed of 215 kts and a range of 1030 nm with a full fuel payload of 735 pounds,
or a range of about 780 nm with a payload of 930 pounds (if you don't use the
aux tank added in the conversion). You can even use reverse thrust to back up.
Of course it doesn't come cheap though.

"Thomas J. Paladino Jr." wrote in message .. .
I have always wondered why there are no small GA turboprops. It seems like
most of the major problems & maintenance issues associated with GA aircraft
are related to the piston motor, and as far as I can tell, turboprops are
much more reliable, fuel efficient, smoother running and easier to maintain.

So it begs the question, why are there no small turboprops in the 100-300hp
range for use on GA aircraft? I would think that turbine engines of this
size would be relatively easy to produce, and would be ideal for GA
applications. The smoother operation and lower vibration levels would also
ease wear and tear on the entire airframe and avionics components. So what's
the deal? Does turbine technology not translate downwards very well? Would
it be cost prohibitive? Am I entirely missing something?

Cessna 210's and Bonanza's can be found with turbo prop retrofits.
These engines run a long time but when its time for a hot overhaul,
its going to cost you an arm and a leg.

Cost and effficiency. Small turbines are very expensive fuel guzzlers.
Large turbines (airliner size) are efficient but small ones aren't. The
1000hp engines on my MU-2 have a bsfc of .52 and smaller engines would be
even worse. Piston engines are in the .40 area. Diesels are more
promising.

Mike
MU-2


"Thomas J. Paladino Jr." wrote in message
...
I have always wondered why there are no small GA turboprops. It seems like
most of the major problems & maintenance issues associated with GA
aircraft
are related to the piston motor, and as far as I can tell, turboprops are
much more reliable, fuel efficient, smoother running and easier to
maintain.

So it begs the question, why are there no small turboprops in the
100-300hp
range for use on GA aircraft? I would think that turbine engines of this
size would be relatively easy to produce, and would be ideal for GA
applications. The smoother operation and lower vibration levels would also
ease wear and tear on the entire airframe and avionics components. So
what's
the deal? Does turbine technology not translate downwards very well? Would
it be cost prohibitive? Am I entirely missing something?

"Mike Rapoport" wrote in message link.net...

Diesels are more
promising.

And can run on the same gas.

"Robert M. Gary" wrote in message
om...
"Mike Rapoport" wrote in message
link.net...

Diesels are more
promising.

And can run on the same gas.

Only some can run on jet fuel. Jet fuel has almost no lubrication
qualities, while diesel does. Jet fuel will eat up some things, like fuel
pumps.
--
Jim in NC


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Morgans wrote:

Only some can run on jet fuel. Jet fuel has almost no lubrication
qualities, while diesel does. Jet fuel will eat up some things, like fuel
pumps.

Any diesel designed for aircraft will be designed to run on jet fuel. Doesn't make
any sense to do it any other way.

George Patterson
I childproofed my house, but they *still* get in.

"G.R. Patterson III" wrote

Any diesel designed for aircraft will be designed to run on jet fuel.
Doesn't make
any sense to do it any other way.

George Patterson

Right. I was commenting on the fact that not all diesels will run on jet
fuel, not airplane diesels. Did I mis-read? Won't be the last time.
--
Jim in NC


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"Robert M. Gary" wrote in message
om...
"Mike Rapoport" wrote in message
link.net...

Diesels are more
promising.

And can run on the same gas.

And there's other sources for diesel...and maybe you can smoke it, too.

http://www.artistictreasure.com/learnmorecleanair.html

On Tue, 25 May 2004, Tom Sixkiller wrote:


"Robert M. Gary" wrote in message
om...
"Mike Rapoport" wrote in message
link.net...

Diesels are more
promising.

And can run on the same gas.

And there's other sources for diesel...and maybe you can smoke it, too.

http://www.artistictreasure.com/learnmorecleanair.html

Smoke my fuel! grin Actually, industrial hemp - the stuff they make/will
make biodiesel, t-shirts, etc out of - has practically NO THC content. THC
is the stuff in pot that actually makes you high.

Industrial hemp is THC-free to the point where you'd have to smoke pounds
and pounds of the stuff to get enough THC into your blood - and the smoke
would kill you dead first!

Brian.