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Turboprop 10?

airguy

Unrepentant fanboy
Sponsor
http://www.aopa.org/News-and-Video/All-News/2014/March/31/turboprop-RV10.aspx

Anybody else have any info on this? The idea is very appealing, I notice the article clearly states early on that Van's is not participating on the project (not surprising). Flight testing is apparently about to start, which puts it in "real project" category versus vapor-ware like the Innodyne (and others). Fuel burn will be high but for a large part of the world fuel cost/availability would make that a net plus.
 
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That is really cool. Saw another company doing the same at OSH last year. Unfortunately, the engine/prop combo cost exceeded the cost of the airframe...by a LOT...:eek:
 
Don't get it

I've never understood the appeal of a turbine engine on an unpressurized sport plane, other than a wow factor / novelty.

The airframe is still Vne limited and the fuel flow on turbines at the low altitudes that RV-type airplanes can fly is outrageous compared to a piston engine.

I understand the turbine on something like a twin otter or an ag plane, where there aren't any pistons in the needed HP range, but there's no way that there is any real advantage of a turboprop in a RV vs a Lycoming.

Disclaimer - I know nothing specific about the TP installation referenced in the article.
 
I've never understood the appeal of a turbine engine on an unpressurized sport plane, other than a wow factor / novelty.

The airframe is still Vne limited and the fuel flow on turbines at the low altitudes that RV-type airplanes can fly is outrageous compared to a piston engine.

I understand the turbine on something like a twin otter or an ag plane, where there aren't any pistons in the needed HP range, but there's no way that there is any real advantage of a turboprop in a RV vs a Lycoming.

Disclaimer - I know nothing specific about the TP installation referenced in the article.

Guessing if you lived in a place where you couldn't get avgas, or it was prohibitively expensive, and the diesel technology wasn't an option, the appeal might seem more apparent. I don't think this turbine is necessarily targeted at the US market where avgas is abundant and (somewhat) affordable.
 
I understand the turbine on something like a twin otter or an ag plane, where there aren't any pistons in the needed HP range, but there's no way that there is any real advantage of a turboprop in a RV vs a Lycoming.....
Ability to run almost any hydrocarbon as fuel would be very appealing to me. Then there's the powerplant reliability. And it would be very cool!
 
155 lbs

At 155 lbs installed, and it does not look like they extended the cowl, or not by a whole lot like the one that has been at OSH for years not flying, I wonder what they are doing to put some more weight in the nose. Guess dual batteries in the cowl would help. Also Projected to have 120 gal of fuel.... that is an expensive fill up.

With it only being a 240hp turbine, it is not so overpowered as others as well.
 
I'm interested in this as a second option to the IO-540. At the rate that 540s are getting hard to find used and the higher and higher cost of new ones, this could be a doable project if reliability and compatability proves they are on par. Not to mention the fuel issue and price of 100LL (and/or replacement later on). This is what experimental aviation is all about! I'll put oxygen in my plane anyway, be happy to get up to 18K and do 200knts IAS but 300knts GS!!!
 
be happy to get up to 18K and do 200knts IAS

Let's see:

200kts IAS at 18000 feet with an altimeter setting of 29.92 and a balmy 20F

True airspeed 272 kts = 313 MPH or roughly 80MPH over Vans published Nne.
Something to think about!

It is experimental and looks and sounds like fun. I too have always been intrigued by a turbine version RV.
 
Let's see:

200kts IAS at 18000 feet with an altimeter setting of 29.92 and a balmy 20F

True airspeed 272 kts = 313 MPH or roughly 80MPH over Vans published Nne.
Something to think about!

It is experimental and looks and sounds like fun. I too have always been intrigued by a turbine version RV.

Yup!

For anyone that hasn't read it previously, the article FLYING HIGH AND FAST may be of interest in the context of this discussion.
You can access it HERE
 
Without a higher thermodynamic rating than 240 hp (most turbines today are flat rated so have SL power available to much higher altitudes) this option will be no faster than an atmo 260hp O-540. Turbines lose hp at about the same rate as atmo piston engines with altitude.

It might be cool but putting in 90-120 gallons instead of 60 won't be so cool...

Whatever it loses in empty weight, it makes up in fuel weight.

It also remains to be seen if this engine will go to 2000 hours like the 540.

It only makes sense if gasoline isn't readily available and you have a fat wallet.
 
Turbine Solutions notes 36 GPH fuel burn. They do not breakdown by altitude. The economics do not pencil out except if 100LL disappears without an alternative.
 
Turbine Solutions notes 36 GPH fuel burn. They do not breakdown by altitude. The economics do not pencil out except if 100LL disappears without an alternative.

Yikes, that's a BSFC of 1.2 roughly- about 3 times worse than a Lycoming running LOP. Turbines don't scale too well downwards and for low cost, this one is probably not very sophisticated and has a low pressure ratio. This figure is probably at full rated power. At 18,000 feet fuel flow is half but so is hp. There is a good reason why they have 120 gallons of fuel here...
 
I still think a lot of people are missing the point. The RV-10 has a Vne based on TAS, ++++ NOT ++++ IAS.

Therefore it doesn't matter if you hang a 1000HP TPE331 (which would be really cool!) on the nose, you are still limited to 200 KTAS.

If you are unsure of the difference, please do some research, flutter is nothing to mess around with...
 
I still think a lot of people are missing the point. The RV-10 has a Vne based on TAS, ++++ NOT ++++ IAS.

Therefore it doesn't matter if you hang a 1000HP TPE331 (which would be really cool!) on the nose, you are still limited to 200 KTAS.

If you are unsure of the difference, please do some research, flutter is nothing to mess around with...

No need to worry with this engine, it won't be any faster than a Lycoming.
 
Turbine Solutions notes 36 GPH fuel burn. They do not breakdown by altitude. The economics do not pencil out except if 100LL disappears without an alternative.

This is data from a few months ago:
36GPH is at takeoff.
130HP at 12K ISA Temp will burn about 52 Kilos per hour.
130HP at 12K ISA Temp will have a BSFC of 0.88 (assuming I calculated it correctly)

The TP-100 is based on the engine core from the TJ-100 which was designed for the UAV market and light airplane market. Specifically self launched gliders and the like. As such it meets the needs and is really light (the TJ-100 if I recall is 40lbs and the TP-100 is about 120lbs). So, as much as I like it, it is not a good fit for most powered aircraft. The exception seems to be the SubSonex

Run the numbers for a self launched glider, ten minutes of power is about 15 Gal which is 105lbs plus 120 for the engine is 225lbs. This is about 100lbs lighter then the installed weight of an IO-360.

Tim
 
The laws of physics apply to all men and machines (and women) equally! Exception might be the F22.

Nothing beats the old Lycosaurus even today.
 
I'm interested in this as a second option to the IO-540. At the rate that 540s are getting hard to find used and the higher and higher cost of new ones, this could be a doable project if reliability and compatability proves they are on par. Not to mention the fuel issue and price of 100LL (and/or replacement later on). This is what experimental aviation is all about! I'll put oxygen in my plane anyway, be happy to get up to 18K and do 200knts IAS but 300knts GS!!!

The IO-540 (one of the most widely used aviation pistons ever produced) is getting scarce and expensive, so we're going to look at a one-off brand new turbine that costs twice what a factory new Lycoming costs and burns 3X the fuel in cruise as an alternative? Huh?
 
Wow I'm surprised as this forum is usually pretty tame about hopping on others comments. I clearly said the wrong thing and apologize for expressing interest in something different!

For what it's worth, there will be a trusty IO-540 in my airplane and I am just fine with that.
 
I will admit my AS comments were unfounded by not keeping in mind TAS vs IAS. Big difference between the two. And I do recognize the airframe's Vne.
 
There are a couple of big implications with all this turbine talk......

Van is going to have to come out of retirement and design a new RV for this engine.

And the engine maker is going to have to turn up the power to 11 or 12...
at least 400 shp to make it worthwhile.

I think some of you guys are getting itchy for a new project.

:D

Glenn Wilkinson
 
Actually, I'd like to see the other way...

Me:
"180 shp, sipping 4gph red diesel, FADEC, 2 moving parts with a 5,000 TBO"

Wife:
"Wake up you idiot, you're dreaming again... And who's Karen?"

CC

And the engine maker is going to have to turn up the power to 11 or 12...
at least 400 shp to make it worthwhile.

:D

Glenn Wilkinson
 
Then there's the powerplant reliability.

Early turbine engines were very unreliable. The major manufacturers eventually learned what it took to build reliable turbine engines. A new, small manufacturer will probably have to go through their own painfull learning process before their engines have the same high reliability we expect from turbine engines from P&W, Rolls-Royce, GE, etc.
 
I think that this engine design has been around for some time...it is pretty reliable.

I would LOVE to have it my -10...if it weren't for the comparatively worse fuel economy, high cost of acquisition, and lack of performance gains (re: Vne=200 KTAS), it would be my first choice of a power plant...

It would be EXTREMELY cool, though...
 
I think that this engine design has been around for some time...it is pretty reliable.

How many of this model have flown? How many of those have over 1000 hours of operation? I'm betting the answer is zero. If so, the real reliability is not yet known. The engine might be very reliable. Or maybe not. We just don't know. We also don't know what installation details are critical to achieve the hoped for reliability, as these details are only learned via service experience.
 
Actually, if you re-read my post, I stated that the engine DESIGN has been around for awhile. Single shaft radial compressor with annular combustion chamber and axial turbine section...sounds a lot like an APU, and there are THOUSANDS of these operating for MILLIONS of hours. Or you might look at the Merlin/Metroliner...myself, I have 5000 hours in the Metro and never had a single hiccup from an engine.

No, I think it is pretty much a proven design. Now whether or not they can make it work in the -10, that remains to be seen. I would give you odds that it will work just fine. Then you look at the Lycoming and all of it's related issues, probably the greatest of which is keeping the darn thing cool, and well, the turboprop starts to look more and more attractive...

Again, if the acquisition cost was reasonable and the fuel flows were comparable, I, personally, would take the turboprop over the Lycoming in a heartbeat.

Unfortunately, that is probably not going to happen any time soon, so it will be a Lycosaurus for my -10:(
 
Actually, if you re-read my post, I stated that the engine DESIGN has been around for awhile. Single shaft radial compressor with annular combustion chamber and axial turbine section...sounds a lot like an APU, and there are THOUSANDS of these operating for MILLIONS of hours. Or you might look at the Merlin/Metroliner...myself, I have 5000 hours in the Metro and never had a single hiccup from an engine.

No, I think it is pretty much a proven design. Now whether or not they can make it work in the -10, that remains to be seen. I would give you odds that it will work just fine. Then you look at the Lycoming and all of it's related issues, probably the greatest of which is keeping the darn thing cool, and well, the turboprop starts to look more and more attractive...

That's a bit like saying that a VW Beetle engine would make a great aircraft engine because it is a four cylinder, air-cooled, horizontally opposed engine, and the good service history of Lycoming and Continental prove that this is a good design. In fact, the early VW users in aircraft experienced many failures, until they learned what modifications were required to achieve acceptable reliability. The Lycoming ALF-502 turbo-fan engine had a pretty terrible service history in the early years, until Lycoming made enough detail design changes to make it a reliable engine.

There is a lot more to reliability than the choice of basic design layout. Details matter. The only way to learn whether they have the details right is lots of test time, either by the manufacturer (if they have the budget for many thousand hours of test time in actual aircraft), or by the early users (i.e. those who choose to be beta testers)

I've had two engine failures over the years, and both were on turbine engines - one was an ALF-502 on a Canadair Challenger, and one was a J-85 on a Canadair Tutor. So much for the vaunted turbine engine reliability.
 
The J85 would quite if it sucked a leaf down the intake or the fuel control was not trimmed perfect and the throttle moved to fast at altitude. Overall I think however you will find the mean time between failures much much better for turbines. 18gph at cruise does not sound good enough However to make this viable. Turbines really need a pressurized aircraft that can get high and go fast.

George
 
The Vne of the RV10 is for its current structure. It can be be reengineered and the Vne can be increased. I'm doubtful Van will do it, but it can be done. It can also be pressurized. It is all about money and desire.
 
money

The Vne of the RV10 is for its current structure. It can be be reengineered and the Vne can be increased. I'm doubtful Van will do it, but it can be done. It can also be pressurized. It is all about money and desire.

That's correct, you can do anything if you throw enough money at it or you could just buy a lancair.
 
"...So much for the vaunted turbine engine reliability..."

Ok. So let's compare stats, shall we? Why not look at all of the piston engine failures with respect to total time in operation versus turbine engine failures with respect to their total time in operation...

Oh, and as for the other post about re-engineering the -10 for a turboprop and pressurization. Yes, it can be done, but as a previous post said, you could just buy the Lancair instead...
 
For a meaningful comparison you would have to take into account the number of turn on and shut downs, something turbines don't like very much or at least significantly reduces their time between overhaul.
The vast number of hours on turbines are accumulated on long flights where most piston engines are accumulating time literally by the hour, sometimes with continuous inputs from the pilot as in training.
I am guessing here, but most of us probably fly an hour at the time give or take, with friends for lunch or sightseeing and return.
I can't see climbing up to 18000 feet for an hour flight and start a let down just about the time you get comfortable looking at your turbine fuel burn and it's time to let down.
I am sure a handful of people would have the means to invest in such a venture but for most of us the Lycoming will be cheapest and best option for a long time to come.
As to the fuel argument, Lycomings run happily on mogas, available everywhere in the world even when jet fuel is not available.
 
Have you considered Rolls-Royce

I may have missed any mention of this, so apologies if I did. But there is a new Rolls-Royce RR300 turboprop/turboshaft engine out. It is currently used on the Robinson R66 helicopter but it has fixed wing applications also. I have no idea of the cost or if Rolls makes it available to the E-AB market. Its power output is around 240 hp equivalent. Based on the M250 of which about 30,000+ have been built, it should be pretty reliable. Might make an interesting install on RV10.

Chris
 
RR 300

Yeah that would be cool but with a SFC of .675lb/hp/hr you would have to carry a ton of gas...

That would be after you pony up $100K or more for the engine and prop...
 
Yeah that would be cool but with a SFC of .675lb/hp/hr you would have to carry a ton of gas...

That would be after you pony up $100K or more for the engine and prop...

I'm not sure $100K would touch it. You might buy one for $100K out of an old wrecked helicopter.
 
Just thinking out loud.... In the spirit of experimentation.

I wonder how a small jet turbine would work to supplement an electric aircraft?
The folks at Jag and ladrover are (were?) working on a small turbine for and electric car. Example of engine here: https://www.youtube.com/watch?v=PFnZJeHc-KY

I have also seen an old video (and for the life of me I can not find it) of a gentleman who build a jet turbine for an RC plane in his garage. And not one of those crappy beer can turbines or those things that use a car turbo. This guy even made his own banjo fittings and bearings on his lathe. It was impressive.

I would think someone could scale one up and build it in their garage for way less than the $150K of a production jet engine.

And now with much lighter batteries available today...go the RC engine / charger / electric motor /batteries route.
 
Just thinking out loud.... In the spirit of experimentation.

I wonder how a small jet turbine would work to supplement an electric aircraft?
The folks at Jag and ladrover are (were?) working on a small turbine for and electric car. Example of engine here: https://www.youtube.com/watch?v=PFnZJeHc-KY

I have also seen an old video (and for the life of me I can not find it) of a gentleman who build a jet turbine for an RC plane in his garage. And not one of those crappy beer can turbines or those things that use a car turbo. This guy even made his own banjo fittings and bearings on his lathe. It was impressive.

I would think someone could scale one up and build it in their garage for way less than the $150K of a production jet engine.

And now with much lighter batteries available today...go the RC engine / charger / electric motor /batteries route.


So after I filled 2 pages with various calculation/option/etc.. to find an RV-10 could stay aloft for about 30 minutes with a theoretical elecric motor.... Then I found this guy already did it for me:

http://www.eaa.org/experimenter/articles/2010-05_electric.asp


even for an RV-10:
"So the third example in this study, the RV-10e would have 44 percent of its gross taken up by batteries. This plane can store 71 kwh of energy, nearly four times the Yuneec or the Cub, but it takes more power to fly (hence the higher assumed motor weight). My simulation shows that it does quite good if you fly it slow. At 70 mph, it will stay up for 1.8 hours. If you crank it up to its cruise speed of 170 mph, then the duration falls to 0.6 hours. (However, if the 10e was streamlined and given a high aspect ratio wing, then…)"

So, batteries are still a limiting factor... I have no idea how much charging capacity a micro jet engine is capable of producing. (See, I'm still talking about having a jet engine, a really small one, in the RV, so this comment is still 'on topic')
 
People scoff but the nextgen batteries are right around the corner and if the projected specs hold up, will have more than FIVE TIMES the power density of Lipos. That would make electric cars with a 300 mile range a reality and electric airplanes more than fantasy. Now probably not the rv-10, but .....

That is until the FAA prohibits them....
 
Turbo Prop RV 10

Where to start... The reasons for putting Turbine in a RV10.
No1: Reliability, Reliability, Reliability !!! In fact Turbines are 100 times more Reliable than piston engines. Just two weeks ago I picked up a RV6A for a friend and only got 90 miles and dropped a valve ( that will get your attention ) and had to make a unplanned landing. No2: 100LL is slowly going to be hard to get and more $.To answer questions and clear some misunderstandings; As with all aircraft with more power, the RV10 with a turbine WILL bust VNE. ( That's where YOU the pilot control the speed, not the ability of the engine / airframe). As with all increases in speed, critically balancing the elevators is mandatory. As for the fuel burn, yes turbines have a higher GPH. They do vary widely. Most small turbines optimal Alt. is 10K - 18K. I am putting a Allison/Rolls Royce B15 317 SHP turbine in my RV10 for the No1 reason I stated only! The fuel burn on this engine at 12500 is 17 GPH. It should fly late this fall. Safe Flying
 
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Where to start... The reasons for putting Turbine in a RV10.
No1: Reliability, Reliability, Reliability !!! In fact Turbines are 100 times more Reliable than piston engines. Just two weeks ago I picked up a RV6A for a friend and only got 90 miles and dropped a valve ( that will get your attention ) and had to make a unplanned landing. No2: 100LL is slowly going to be hard to get and more $.To answer questions and clear some misunderstandings; Yes VNE in the RV10 is 230 MPH ( INDICATED ) is the key word here!! Remember as Alt goes up indicated A/S goes down because thinner air. Just as the Citation's I fly the VNE is 267 KTS but at 35K the indicated is about 180, true is 390 !!! As with the Citation, the RV10 with a turbine WILL bust VNE below a certain Alt. ( That's where YOU the pilot control the speed, not the ability of the engine / airframe). As with all increases in speed, critically balancing the elevators is mandatory. As for the fuel burn, yes turbines have a higher GPH. They do vary widely. Most small turbines optimal Alt. is 10K - 18K. I am putting a Allison/Rolls Royce B15 317 SHP turbine in my RV10 for the No1 reason I stated only! The fuel burn on this engine at 12500 is 17 GPH. It should fly late this fall. Safe Flying

Turboprops are not 100 times more reliable than piston engines:

http://www.ntsb.gov/doclib/recletters/2003/A03_58_61.pdf

http://www.airlinepilotforums.com/technical/65850-pt6-failures.html

http://www.pprune.org/tech-log/9309-pt6s-let-go.html

http://africanbushpilot.blogspot.ca/2010/01/caravan-engine-failure-severe-pt6-turbo.html

One of my friends who has over 25,000 hours on many types of aircraft had his only engine failure with a PT6 Caravan. Sheared fuel pump drive. Gearbox and FCU problems are not all that uncommon.

Yes, these are more reliable than piston engines but not as reliable as many people might think. Transport Canada did a study here: https://www.tc.gc.ca/eng/civilaviation/publications/tp185-3-07-feature-3772.htm Questions some of the reliability stats P&W provides.

Vne on Van's aircraft is TAS, not IAS.
 
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I was in a B200 when it had a failure, But Stats show turbines are more reliable. And I'm not using a PT6

From the link:
reduction of CFIT/night VFR accidents in air taxi operations;
higher reliability of turbine-powered aircraft relative to reciprocating engines would constitute a lower level of risk than VFR flight in marginal conditions; and
approval of SEIFR would influence aircraft purchase decisions in the direction of more reliable, safer turbine-powered aircraft.
The main point is they are more reliable, even if it's only 25 times more reliable that's a huge margin for safety. I do stand corrected as for Van's using TAS as VNE limit not IAS as with all certified aircraft. But as I have stated, speed / performance is NOT factor in my decision to use a Turbine.
 
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I am putting a Allison/Rolls Royce B15 317 SHP turbine in my RV10 for the No1 reason I stated only! It should fly late this fall. Safe Flying

I bet a lot of us look forward to hearing how it turns out and flies Alan.

You really do, however, need to take a look at the many, many posts about flutter speeds in the RV line - they are TRUE airspeeds, not indicated, and Van's has written a lot about that - referenced in a post above.
 
Thanks Paul, I have researched and have read many post on flutter, especially Smoky Ray's. I have researched O&N's Silver Eagle Cessna 210 Allison conversion as well as the TradeWinds Bonanza. I am very cautious of this and as I said, critically balancing will help minimize this. This is not my first RV to build, I've built a RV-7A and helped with 3 others and finished a Skybolt. and have 400 hrs in RV's. I'm a A&P with 25 yrs exp. and a Commercial pilot in Citations and have experienced my share of inflight emergencies. The worst was a double Gyro failure at night in IMC in a Citation, Not Fun. Smoky Ray is right about flutter, You get little to no warning and it's usually it happens very fast. This has been a concern from the start.
 
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Yes VNE in the RV10 is 230 MPH ( INDICATED ) is the key word here!! Remember as Alt goes up indicated A/S goes down because thinner air. Just as the Citation's I fly the VNE is 267 KTS but at 35K the indicated is about 180, true is 390 !!!

Dude, the engineer that designed the RV, Van himself.... Has reiterated MANY many many times, that VNE in his airplanes is based on TAS.

The only way to attribute turbine engines to night/cfit/135 ops safety is more experienced pilots... Otherwise the power plant up front has nothing to do with it. A Commander 690 slammed into the Superstition Mountains in 2011, at night, VFR. It had two turbine engines. :confused:

And no Citation has ever gotten close to VNE/MMO. :D
 
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Alan W.

You posted, "... Yes VNE in the RV10 is 230 MPH ( INDICATED ) is the key word here!! ..."

Sir, please, please, please do some research.

The statement you made is ABSOLUTELY FALSE! The Vne on the RV-10 is 200 knots TRUE AIRSPEED. If you don't believe the people on the forum, then a simple call to Van's will verify it...

The experimental community does NOT need any more accidents!

If you intend to put the turboprop on an RV-10, great! I would love to hear how it performs. I would do the same if it weren't cost prohibitive. The difference, though, is that if I installed the turbine on my RV-10, I would respect the designer's Vne of 200 KTAS.

As an Aerospace Engineer, I know what goes into the design process, and know that flutter is nothing to mess around with. Van designed the -10 and put limits on it for a reason...

If you want to go high and fast in a turboprop experimental, maybe you ought to consider the Lancair...the engineering has already been done...
 
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