Yep real turbine
Hi George,
Flying helicopters, the idea of being able to Zip along at 210kts plus for 130lbs / hr consumption seems really good value.
Props seem to be the problem, and the airframe constraints are interesting.
I have just viewed the Innodyne site - not sure, all new and unproven Nothing like a RR badge for the confidence.
Yea 19 gph is pretty good but would you not want to zip along at 210 mph at 10 gph? I agree the Allison/RR is a real turbine and the Innodyne is kind of a toy, with no real fuel/prop control, or at least sophisticated fuel/prop controls typical of tubro-props. Yes the whole gear box, prop control and fuel controller is the challenge.
When you are in the 400HP range and under, the PISTON ENGINE rules on economics and practicality. You will burn 1/2 the fuel with piston engine. Now when you get into the +400HP piston engine, you're talking a turbo-geared-supercharged-6/8 banger or a radial.......so turbines start to earn their keep. Under 350 hp forget the turbine. It's more a novelty in the low HP range. If your making a living with a plane turbines rule because of the reliability and maintenance schedule / TBO, but cheap they never will be.
Now if I was going to do a turbine kit plane, my first choice the PT6. Too expensive? The Lancairs are using the cheaper East Euro PT6 copy, the Walter. They where cheap for awhile when first imported, like $60K for a used engine, props $15-20K?? The price has gone up. It has gas coupled core to prop section (like a PT6), that makes starting easier, verses direct drive turbines. The Walter starts in the +600HP range, not 300 hp. Some models of the Allison/RR 250 are setup for planes, but not sure how to get one since they are not many flying on planes.
My second choice is based on personal experience flying the Metro, the Garrett TPE331. I'd look for a total FWF set-up, off a Mitsubishi MU-2, Swearingen/Fairchild Metroliner or BA Jetstream. The full meal deal would include: prop, gearbox, strain gauge torque meter, turbine core, prop/fuel controller integration and accessories, all in a super small package. The down side is the base line is around 900 hp, way too much for a RV. You can "de-rate", but what about a RV airframe? Forget it. It would be capable of +300 kts TAS. That's a little over Vne for RV's. Let say you found one with time left on it. It's going to cost some coin. Turbo-prop means BIG cash to buy and feed. I think that is the reality you are not gripping. The planes I fly can burn 20,000 lbs/hr of fuel in climb! Spectacular yes but would not (could not) pay for it.
Ag planes and utilitarian planes like the Cessna Caravan are good turbine platforms. The Lancair IVP I'm sad to say has a poor safety record, especially the turbines or "Propjet" models. A turbine IVP is for sale on salvage right now, due to landing accident and/or loss of power. There where also 3 fatal Lancair "Propjet" accidents in the last year, killing 7 people. It's not as bad as the BD5J, the other jet dream. My point, little planes and turbines tend to not mix well. Airshow pilot Wayne Handley almost got killed in his turbo-prop acro plane. To me, "turbine" or jet spells work, utilitarian, more than sport plane. I like the "suck-squeeze-bang-blow" of the piston engine. When I win the lottery I'd skip the turbo prop and get a VLJ, little jet or a older used Citation 500, which I have a type rating in.
