GA Turboprop

[Flyfalcons]

That's too bad. At what price do you think a turboprop would be interesting for the majority of general aviation?

Since the majority of general aviation is flying 200hp or less two to four seaters on short to medium distance flights, it's going to have to be pretty low.

[martymayes]

If technology advances to the point where a turbine engine can be had for a ~50% premium over a comparable piston engine, you'll have the majority of the GA fleet on turbine power in 20 yrs. or less. Obviously, a lesser cost would accelerate the conversion.

A 100 eshp turbine powered LSA would actually be a joy to fly on a local sight seeing mission or hr of touch-and-go training. Pilots would adapt quickly. Flying a piston engine airplane would become more of a curiosity than a necessity...kinda like flying a biplane today.

[Mike Switzer]

Supposedly Allison is still working on a small turbine. I have thought about trying to convert one of CAT's Solar turbines for aircraft use, but the models available in the HP range we are looking at are generally designed for generator use running at a set RPM.

[rwanttaja]

Well, Detroit has played with gas turbine engines in cars for a long time and they have yet to hit on the right combination of practical and affordable. The stumbling block seems to be finding a recipe for mass-producing the internals. Lot of engineering talent and $$$ has been expended looking for solutions.

That's basically the problem. You can build a pretty decent reciprocating engine with some steel and a good machine tool, but turbines are high-precision equipment. They often run hot and need exotic materials. Companies can and have cranked out new aviation recips using CAD-CAM resources (The Rotec and the Sadler radials come to mind) but AFAIK no one has done anything similar with a turbine.

Coupled with their higher fuel consumption and the fact that they're more efficient up high, it's hard to come up with a design that'll be suitable for the run-of-the-mill GA airplane.

Guy came to our EAA meeting once with a Solar T62 APU conversion. Pretty neat package, and I had fantasies about putting one in my Fly Baby. The ONLY thing that made them anything near economically feasible was the availability of used T62s on the surplus market.

Ron Wanttaja

[steveinindy]

And as for as not wanting to have to talk to ATC for all of every flight, darn right. Now sometimes the weather is IMC, and part of getting through it is to talk to ATC. But on a nice CAVU day, particularly if flying in less crowded airspace, I certainly don't want to spend several hours of a flight listening to ATC yammer. It would be like if you went for a walk in the woods or a pleasure drive in the country or a bike ride and you were required to listen and talk to a local cop channel or talk show radio.

I guess the fact that I don't view flying as relaxing, especially at low altitude on severe clear days when there is more traffic around, probably has a lot to do with why I like having ATC tuned in. Not to mention that if I will be airborne for several hours it helps to break the monotony.

[kjensen]

What are you guys' opinion on the new Diesels that are out now? Is that something I should consider instead? They seem expensive (compared to gasoline pistons), and I'm not sure if the fuel savings will ever make up for that price difference if I only fly around ~100hr/year. So if the fuel savings won't be the reasons to go for a diesel, are there other advantages other than that? The only other thing I can come up with is the use of diesel/jet-a instead of 100LL. Any other reasons?

[Thomas Stute]

There is another alternative to reciprocating piston engines other than turboprops, the modern rotary engine as developed by the swiss company Mistral Engines http://www.mistral-engines.com/. They are perfectly suited for GA with 200 hp to 360 hp. The mistral engines burn leaded/unleaded fuel, avgas, mogas, even ethanol containing fuel. It has already flown in a Maule and in a Piper Arrow. Mistral will be exhibiting their engines on the AERO these days at Friedrichshafen and I'm going to visit them at their booth. I will be posting more when I've got more recent info on their status.

[Mike Switzer]

What are you guys' opinion on the new Diesels that are out now?

Still too heavy for the power they produce, but some of the European automakers are coming up with some promising lighter weight designs. Unfortunately, they are all computer controlled, and I have some reservations about having a single ECU that may fail while over hostile terrain.

[steveinindy]

Unfortunately, they are all computer controlled, and I have some reservations about having a single ECU that may fail while over hostile terrain.

As opposed to the FADECs that are common in turbine engines? I would rather have a ECU than a carburetor.

What are you guys' opinion on the new Diesels that are out now?

Still too heavy for the power they produce

I'm with Mike on this one.

Is that something I should consider instead?

From the sounds of it, you have very little reason to go with something other than a turbocharged reciprocating engine. Unless you're looking at flying really high (as in the flight levels where pressurization is a must), have a NEED to go very fast (such as wanting long range (>1500-2000 miles) while keeping flight times to a minimum) or are going towards the heavier end of the GA spectrum (>5,000 lbs) then you have very few reasons to really be looking at anything other than a good ol' fashioned reciprocating engine.

The only other thing I can come up with is the use of diesel/jet-a instead of 100LL. Any other reasons?

The biggest benefit is that if you want to fly outside of the US, you're best off having something that runs off of Jet-A or a similar kerosene fuel. Also, it removes any need for a possible switch of engines in the event that an unleaded aviation fuel isn't available in all areas when 100LL goes away.

[uavmx]

Rolls Royce seems to be making something that is similar or at least the closest thing to what we are talking about

http://www.rolls-royce.com/civil/pro...aft/model_250/


anybody know what these puppies cost new???