GA Turboprop

[kjensen]

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.

Will 100LL go away as long as there are no direct substitutes? That would mean hundreds of thousands of airplanes won't be able to fly. Even though EPA are trying to scare the aviation community, do you think it ever will happen unless there is a backwards compatible substitute?

[uavmx]

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.

Wow, those look pretty nice, same idea as turbine in terms of less moving parts/reliability (although it's still dependent on ignition system)

Any idea what the different models of theirs costs?

[steveinindy]

Will 100LL go away as long as there are no direct substitutes?

Are you willing to bet a lot of your own money that it won't?

That would mean hundreds of thousands of airplanes won't be able to fly.

Do you really think they give a shit about small aircraft? Just because it's a concern to us, doesn't mean that it even factors into their thinking.

Even though EPA are trying to scare the aviation community, do you think it ever will happen unless there is a backwards compatible substitute?

There's already a solution for the aircraft that anyone in Washington (who isn't a private pilot themselves) cares about. It's called Jet-A.

That said, there's likely to be a replacement either in the form of Swift Fuel or something similar. However, if you want to go to anywhere outside of the US, it's probably best to not rely on something that runs off of a gasoline variant.

[steveinindy]

anybody know what these puppies cost new???

More than what most experimental aircraft cost including the engine. If I had to ball park it, I'd say probably the $150K-250K range.

That said, you could probably get one of the military surplus variants (the T-63) for much less.

[kjensen]

Are you willing to bet a lot of your own money that it won't?

Nope

Do you really think they give a shit about small aircraft? Just because it's a concern to us, doesn't mean that it even factors into their thinking.

Probably not, but if there are 200,000+ people that voice their opinion I would think it could make an impact...

That said, there's likely to be a replacement either in the form of Swift Fuel or something similar. However, if you want to go to anywhere outside of the US, it's probably best to not rely on something that runs off of a gasoline variant.

What about regular auto gasoline? Can't lycoming and continental modify their engines to work on that?

[steveinindy]

Probably not, but if there are 200,000+ people that voice their opinion I would think it could make an impact...

You're assuming that all pilots give a shit and are willing to speak up. A lot of us honestly don't care. I for one will be glad to see the day when leaded gasoline is done away with. I just hope the infrastructure for a replacement is in place prior to it happening.

Can't lycoming and continental modify their engines to work on that?

Theoretically yes, but there are a number of reasons why it's not as easy as it sounds.

Do you mind if I ask your background (age/education/training level)? You ask a lot of questions that make you sound like you're a student pilot and it would be helpful in explaining stuff if I knew where you stand in terms of basic knowledge.

What about regular auto gasoline?

Congratulations by the way, you probably just triggered this thread being turned into another "No ethanol in my gasoline!" debate.

[kjensen]

Do you mind if I ask your background (age/education/training level)? You ask a lot of questions that make you sound like you're a student pilot and it would be helpful in explaining stuff if I knew where you stand in terms of basic knowledge.

I'm a student, university level, and a student-pilot. I'm writing an assignment on disruptive technology for one of our classes. I chose to writing about turbine engines, and while I was writing I just realized that turbine engines have been disruptive in every part of aviation except most of general aviation, which is why I went here to maybe get an answer why that is the case.

[steveinindy]

while I was writing I just realized that turbine engines have been disruptive in every part of aviation except most of general aviation, which is why I went here to maybe get an answer why that is the case.

Ah. Like with most things, it boils down to cost and the existence of technology much more suited to the nature of the "average" pilot's flying. There's also this huge lingering (often just below the surface) disdain for the "kerosene club", as demonstrated by some of the comments here. A lot of it also comes out as by switching to non-reciprocating engines, that is somehow tantamount to an abandonment of what aviation is "supposed to be all about" especially when it comes to the EAA side of things.

[kjensen]

There's also this huge lingering (often just below the surface) disdain for the "kerosene club", as demonstrated by some of the comments here. A lot of it also comes out as by switching to non-reciprocating engines, that is somehow tantamount to an abandonment of what aviation is "supposed to be all about" especially when it comes to the EAA side of things.

So a lot of the pilots won't change because piston engines is sort of an identity to general aviation? Do you think that can change?

[Kyle Boatright]

Will 100LL go away as long as there are no direct substitutes? That would mean hundreds of thousands of airplanes won't be able to fly. Even though EPA are trying to scare the aviation community, do you think it ever will happen unless there is a backwards compatible substitute?

I certainly hope the answer to your question is "No". However, the vast majority of the Cessnas, Pipers, etc. at your local airport can run on 91 octane fuel, which is easy enough to achieve without lead content. Those aircraft wouldn't be grounded if lead was removed from Avgas. The problem is that the expensive aircraft with the most powerful engines in the piston fleet (most anything that is turbocharged or has higher than 8.5:1 compression) need more than 91 octane. Those are the aircraft which work for a living and burn a substantial amount of the Avgas that is consumed.

So the elimination of 100 octane fuel would ground much of the "working" GA fleet, which would have a very negative impact on the rest of the piston fleet, simply because it would cause an even further decline in Avgas sales. That would tip another domino in the decline of piston GA.