Turbine power ...

[Spike]

I dont know if you saw it this year or not but there was a company at Osh '04 that brought a turbine powered RV-4 to the scene. There was a write up about it in avweb today. I was wondering if this was at all attractive to you? With all of the talk about 100LL and such I think this would be a neat way to go.

-- John

[Guest]

John,
I thought about the turbine engine for my "8" -- for about 3 seconds! Then I thought about the fuel they use and that 42 gallons wouldnt run it very far. And my wings are finished and I don't want to modify them to hold more fuel. Then I cannot afford that much for a turbine engine. Then the prop would have to be a reversing prop --lots of more dollars. Sooooo I just setteled for a lycosaur clone and a C. S. prop and they will do just fine.

Dan N742DA Flying in the spring!

[Spike]

All very good points. I cant help get excited though at pulling up to a ramp and having everyone listen to my engine spin down. Boy would that be slick

[flyerfly]

I too was very interested in this option but have not been able to obtain any information about fuel consumption . Unless I see some real data I feel that my RV7A fuel tanks will also be to small.

If the current tanks are too small for this powerplant then my wallet is also to small... Time will tell of course but I am not sure I can wait that long, I need to get going on the finishing kit and that means engine stuff.

There is a yahoo group about this engine but there is no concrete information there either about fuel consumption. It sure would be neat if this thing worked though...

Jon

[captain_john]

We discussed this at length on another BBS and it is still "too" experimental. Fuel consumption is a big concern for sure.

Nevertheless... SLICK!

CJ

[N200PF]

Hey guys sorry for the late post on this! I just saw the thread...

I actually called and spoke with the owner of Innodyn a few weeks ago to ask him all the questions you're bringing up. Chuck was GREAT and willing to spend a ton of time on the phone talking about how the turbine will differ and what the advantages / disadvantages would be to a good ol' Lycoming. (Flying by the temp gauges etc.)

Fuel burn on the 255hp at full power was an ESTIMATED 14 gallons an hour. The 200hp would be closer to 12 gallons an hour. He said these are absolutely estimates and they hope to get better than this as the fuel management system is fine tuned.

The big advantage is of course the 10,000 hour TBO they're working towards (it's 5000 now) and the reliability of a turbine! Even at 60,000 rmp you could fly that thing 500 hours a year and not have to work it over for 5 years! (OK how much JetA would that be?!?)

Anyway, I think it's a GREAT option for about the same money as a new Lycoming! If they can get the fuel burn on the 255hp down closer to 11 or the 200hp in the single digits I am in! (I hope my insurance company will be in!!!)

I'm with spike on the ramp appeal! I have listened to the start up video on their web site about 100 times! How sweet would that be!!!

Here is the site: http://www.innodyn.com/

- Peter

[RV6junkie]

Those fuel burns look very good!

Keep in mind, a 200 HP IO-360 will burn 14 gph at WOT, but at cruise, where the engine in only making 150 (75% power) the engine will still burn 9 to 10 gph. With that in mind, the mini-turbine seems to have a little better SFC. I would expect that at the same 150 HP setting, the turbine will be in the 7 to 8 gph range....not bad at all. Even at a 200 hp setting the turbine is burning almost the same amout of fuel as the piston engine at a cruise setting.

[Spike]

I just spent some time at their website and I have to say that I am very much interested in this. I think Jet-A is the wave of the future for GA and what better way to burn it than in a turbine!!

WOW

--John

[Guest]

I don't know much about how the turbines work but if I remember right, Chuck said the fuel burn is what it is. In other words, they don't recommend spooling down the turbine at all. They want you to flyit at 60,000 rpm in the pattern and up at 14,000 feet. It just all about the prop pitch.

If you spool the turbin down, it would take too long to add a burst of power if you needed it to correct on final. If all you have to do is pitch the prop to add power you would have all you needed!

...or you could fly perfect power settings and NEVER need to adjust power on final like I do! YEAH RIGHT!

Anyway, according to Chuck the turbine's either running or it isn't so 12 to 14 GPH it is. No 5 GPH coming out of 9 for 3...

All in all I am certainly considering it! Chuck invited me out to State College for a look this spring and I plan to take him up on it! Don't worry I'll bring the camera!

Has anyone else called over there to see how the testing on the RV-6 is going?

- Peter

[N200PF]

OK Busted! I'm up at the cabin again on a different computer and forgot to log on...

Sorry!

- Peter (N200PF)

[Spike]

My big question is what are the failure modes if you should loose prop control?

-- John

[4kilo]

The fuel burn in a turbine is dependant upon not only the rpm, but also the pnuematic loads on the engine. Since the main load on the hot-section of a turboprop engine comes from the propeller gear box, changing the prop pitch, prop RPM, or even the airspeed will drastically change the load on the engine. Therefore, reducing the load on the engine, even while maintaining a constant RPM on the hot-section, will decrease the fuel flow.

Spike, since I have not researched this engine, I can't tell you how they have failure modes fail-safed, but it is very unlikely you could use a standard recip CS prop anyway. There are usually fail-safes set up between the propeller governer and the turbine fuel control unit (which is actually also a form of governer) which will prevent overspeeds and the like.

I have about 12,000 hours flying various types of turboprop aircraft, and although the power and capabilities of a turbine are quite attractive, I am building an RV mostly because it is a simple (read inexpensive) aircraft to build and maintain. Before I considered the complexity and cost of installing a turbine in one, I think I would rather consider building a home nuclear reactor (it would probably be simpler and less expensive).

Pat

[Dan A]

One other thing to think about . The prop for the turbine would probably have to be of the reverseing type like most turbines have. That means the prop could cost as much as the engine.
Dan

[Spike]

According to their website they were using and recommending an electrically controlled prop. My thoughts were along the lines of losing power (stuck pitch). At that point how would you control power if the turbine is fixed at a constant RPM ? Is that a rule, or just a general operating procedure?

[svanarts]

I dont know if you saw it this year or not but there was a company at Osh '04 that brought a turbine powered RV-4 to the scene. There was a write up about it in avweb today. I was wondering if this was at all attractive to you? With all of the talk about 100LL and such I think this would be a neat way to go.

-- John

I keep hearing people talk about the talk that says 100LL is going away but I've never really read or seen any info on 100LL being phased out. Is there some info somewhere where I can read about it?

I think probably a more realistic alternative is probably a diesel engine. But I've yet to see a good production aircraft diesel engine yet either aside from the Diamond TwinStar. Of course, taxiing up to the pump behind a diesel won't sound quite as good as taxiing up behind a turbine. It might be cheaper though.

[4kilo]

My thoughts were along the lines of losing power (stuck pitch). At that point how would you control power if the turbine is fixed at a constant RPM ?

This solution to this problem is a "precautionary engine shut-down." The proceedure is a much more attractive alternative in a multi-engine aircraft.

Pat