Any Innodyn news?

[cjensen]

according to their FAQ section on the website, they are supposed to be shipping customer engines this quarter ending 2005. anybody heard anything, or have one yet??

[gmcjetpilot]

I don't think the panache or aura of turbine whine and smell of kerosene will ever fade, especially a cheap turbine? May be it is like owning a P-51, may be attainable but never practical or cheap. Innodyn or not I don't think small turbines are practical in general and in a RV airframe a particular an even poorer match. Where do you see single engine turboprops, Cessna Caravan, Pilatus PC-12, SOCATA TBM-700 and Piper Meridian. There are some notable conversions of Dehavilland Otters and Beavers. So it seems the aerospace industry has sized the practical use to cabin class singles and utilitarian haulers.

I looked all the successful turbo prop experimentals an some factory planes, well successful is a relative term. I flew a Swearingen Metroliner SA227, so I know a little about turboprops. The Lancair Turbine program (projet) I think uses a Walter de-rated / flat rated 750 shaft HP engine. Not sure what the engine cost is but I thing engine and prop will be the better part of $150,000.

As far as other prop jets there was a Luscombe (yes a high wing taildragger) that was for sale as part of bankruptcy on the NET just a few weeks ago. It uses a small Solor APU engine rated up to about 160 HP. Its fuel burn is 1.3 lb/shp-hr. If you do the math it is quite a fuel flow and still makes less than a Lycoming O360. Innodyne claims some crazy 0.7 lb/shp-he efficiency? I remember seeing this Solor Propjet Luscombe at a few airshows in the late 90's. It was not practical as a power plant in general and much less for that airframe in particular.


Besides the 750shp Walter, the only other turbo props in contention I can think of are the Pratt & Whitney of Canada PT6's and The Garrett TPE 331's. They all come in at 600+ HP and typically 700+ HP (up to 1000shp). If less HP is needed or allowed on take off they flat rate it, which means the fuel controller reduce fuel to lower sea level HP. Since the engine is de-rated it can maintain that sea level power to a higher altitude, and which point power falls off with altitude. This kind of power will OVER POWERS most experimental aircraft. Obviously the RV with a 220mph Vne (that is TRUE AIRSPEED BY THE WAY NOT INDICATED) is not going to handle that kind power.


My choice if I could dream of a personal turbine engine would be a Pratt & Whitney PT6, but the cost and size would not make it suitable for a RV or even a Lanciair. The Walter (made in Eastern Europe) is of a similar design to the PT6 but cost less, so that is probably the reason Lancair supports the Walter as their turbine candidate. Either way you are looking at 500+ de-rated shp at least. A RV-x can not use that much power (Vne).

The nice thing about a PT6 (and Walter) is its a free turbine where the turbine the drives the gear box, that drives the prop, is separate and not mechanically connected to the "Gas Section" of the turbine. It is connected by hot gas only and the power turbine is FREE to spin independent of the GAS turbine. This allows the turbine to "spool up" with out immediately turning the prop. Direct drive turbines where the prop is mechanically connected to the gas section are harder to start and need big batteries (banks of batteries), since you have to turn the prop while starting as well as the "gas section". The Metro IV (Garrett TPE331) is like this and why you always see JUMP Cart's on airplanes using these engines. The jump cart provides extra battery power. You can start on internal battery only but it is hard on the batteries and the engine starts much hotter. The "battery" jump cart allows the engine to turn faster during start. Failure to turn a turbine fast enough during start, before adding fuel, can cause a HOT START and destroy the engine.

As far as pure jets, Greg Richter of Blue Mountain Avionics converted a GE T58 turbine normally used for Helicopters by removing the accessory case and using it for it's jet thrust alone, about 800lbs thrust. The article of Greg's Jet powered Cozy is in the EAA Sport Aviation Magazine this month or last month. The bottom line it works and works well, but Greg's last statement is it is NOT practical. The RV is not suitable for jet thrust obviously but the advantage of just chucking all the gear box and prop control is pretty obvious. Although not practical as Greg said the performance is of his JetCozy is impressive. However economy is not the hallmark of jet travel, especially in a two seat plane with little cargo/baggage.


That leads me to the Innodyn. First they have not done themselves any favor with some of the semi-data they have out there, which seems to defy normal efficiency by a factor of 2. Also the history of the company and promises others can speak to make me wary of purchasing one.

My conclusion is there is no chance a suitable small turbo prop engine in the 180-250 HP range is really possible (practical). THERE is an economy of scale. If you are going to make a true aircraft capable turbine designed for the purpose of being a power plant for an airplane, it is going to come in at least in 400 hp and more, like the 600 hp range. They will also cost well over $100,000. Also the RV is not big enough or have a high enough Vne to take advantage of turbine power. If you want a jet the Lancair/Walter seems to be one of the the best things on the market.

Can a RV use a de-rated 700HP engine? I doubt it, a Pressurized airframe like the Lancair is a better match. RV's are just NOT jet aircraft. The Jet Powered Cozy Greg Richter, although not really practical is a better match, in my opinion, than any turbine in a RV.

Now can Innodyn really make a 180-220HP turbine that is cheap, practical and safe. Well from what I know they have made some simplifications is design and systems to make it work at the "SCALE" or size they are at. Every turboprop is usually saddled with a heavy complicated gear box, hydraulic prop, torque measuring device (usually strain gages) and fuel controllers. All this stuff is complicated and expensive. Is it worth it to have all these items only for 200 HP? Innodyn has simplified the prop (no hydraulic prop), gear box (no torque measurement) and the fuel controller are all no doubt simplified.

You can put a turbine on anything:
http://www.aardvark.co.nz/pjet/turbinenuts.shtml

But that does not mean you should. If you want a Turbine Jet aircraft plan on at least 1/4 million dollars, not $80 grand. The RV will never be a great match for a turbine and practical turbo prop powerplant/props are at least +600HP. At this time I don't see Innodyn being practical. More important is safety. Is it safe?

Here is my idea for a cheap turbo prop engine prop set up. I would buy an wrecked TurboProp Aero Commander with two good Garrett TPE331's with a partner. We would part the plane out and use the two engines for two single engine projects. The airframe could be any high speed aircraft (Lancair), Thunder Mustang or may be a big heavy hauler bush plane designed for a IO540 and super size the plane. (If you can't go fast go heavy to take advantage of the HP.) You would get all the engine instruments, controllers, prop (you hope not damaged) and bits and pieces to make them run. PT6's are better but just too popular and you will pay a fortune. The TPE331 have been around and have got to the point of high reliability. The Dash 10 models are very good. These engines or variations are in Cessna Conquest, Aero Commanders, BAe Jet stream and Fairchild/Swearingen Metro. The latter commuter planes have higher HP versions up to 1200SHP with AWI (A-we). AWI is alcohol water injection.

I would never discourage anyone's JET DREAMS, but I think there is better ways to go and would go with a REAL aircraft turboprop and not this experimental set up.

George

[rv6ejguy]

Innodyne has been putting back delivery dates for some time so hard to trust what they say. I agree with George, the published FF numbers are highly unlikely with this design of turbine and pressure ratios involved.

I friend has been installing a 425hp Allison turbine in a Glassair now for almost 4 years with professional help. Still not done, lots of heachaches and lots of $$$. He said he would NEVER do it again.

Another friend has a shop building composite turbine aircraft up here. Doing the Glassair, 2 Lancairs and a Legend (was Walter now installing 1000 shp Garrett!). These people all have big $$$$ and they'll need even more to buy the fuel for them operating at low altitudes.

There are some 150-250 hp turbines available but need suitable gearboxes designed to be usable. If you really must do this try Shane at Innovative Wings http://www.innovativewings.com/ up here in Canada. They have a lot of experience with turbine homebuilts.

Turbines are very cool but cheap they aren't. You'll need some really big tanks to make it usuable on an RV and watch that ASI if you install something over 200hp.

[gmcjetpilot]

Originally Posted by rv6ejguy

Turbines are very cool but cheap they aren't. You'll need some really big tanks to make it usable on an RV and watch that ASI if you install something over 200hp.

Everything you said rv6ejguy, and that's want I wanted to say but you did it in 1/10th the words.

One thing I would point out is Flutter speed or Vne is not IAS. Flutter or Vne is based on TAS. Since for every Knot/MPH IAS, TAS increases roughly 2% for every thousand feet, e.g., at 10,000 feet, 100 mph indicated is really 120 mph (10 x 2% = 20% difference). If sea level Vne is 220 indicated, Vne is ONLY a 169 mph IAS at FL180 (18,000 feet), or 220 mph TAS. With Turbine power you may be able to maintain sea level power well into high altitudes and easily exceed the Vne of the airframe.

For most RV'ers Vne in level flight at any altitude is not an issue since piston engine HP goes down with altitude, so we tend not to push Vne in level flight. However if you are descending fast from higher altitudes you can exceed Vne easily if you are not conscious of the relationship of Vne and IAS with altitude.

I think Doug posted the RVator article. Jets you don't use Vne or IAS above 20,000 / 25,000 feet. All limits are base on MACH number. Since MACH one (speed of sound) decreases with altitude your MACH limit or Vmo (Max Mach is like Vne but in MACH# not knots or MPH) remains constant. Unlike IAS, Vne in IAS is a function of altitude and always changing with altitude. So with a turbo prop you will not be able to take advantage of that excess high altitude power reserve and higher associated speed, unless the airframe has a high Vne/Vmo. This is one of the problems with the Beach Bonanza turboprop conversion, which does use the Allison which I forgot about as a popular small turbine that rv6ejguy mentioned. What do one of those factory fast single engine Turboprops from Piper, Pilatus or SOCATA cost?

I guess I am just going to keep my RV-7 and put some turbine sounds on my Ipod and pipe it thru the intercom. I guess I can put a little injector in the exhaust pipe and spray a little tiny amount of kerosene in for the smell?
G

[cjensen]

whoa...wait a minute here, i was just wondering if there was anything new in development from innodyn that wasn't yet published on the website.

i think this is an interesting idea, but who knows where it will really lead. i do know a little about a little about turbo props since i crew a king air for my fbo (no biggie, you didn't know that), so a lesson is not necessary here. however, i do appreciate the opinions on the little innodyn. i don't have anywhere near the amount of money that would be required to even think about a pt-6 or 331 (maybe even an innodyn), but i do believe that the small turbine has plenty of promise to be a viable option in the 180-200hp range someday. it may not be this company that pulls it off, but we have the resources to make this work someday.

you gotta believe!!

[gmcjetpilot]

Originally Posted by cjensen

whoa...wait a minute here, i was just wondering if there was anything new in development from innodyn that wasn't yet published on the website.

i don't have anywhere near the amount of money that would be required to even think about a pt-6 or 331 (maybe even an innodyn), but i do believe that the small turbine has plenty of promise to be a viable option in the 180-200hp range someday. it may not be this company that pulls it off, but we have the resources to make this work someday. you gotta believe!!

What King air do you fly? Cool. Yea it is a general discussion for anyone to read not only someone with your experience. We do differ in the thought or opinion that 180-200 hp is practical for a turboprop as I mentioned, but I could be wrong; I hope I am wrong, and if Innodyn does it, great. I have doubts with Innodyn but more power to them (pun intended ).

I think the real future myself is in small jet turbines. Turbo Props are just too complicated. They do have their niche in business aviation and short haul freight. Turboprops are gone or fading from commuter aviation in most markets. I have done the commuter turboprop pilot thing, corporate Jet captain on Citation's (when there where just 2 basic models the 500/550 and 650, now there are several more models) and now fly larger jets. To me props are great and love piston engines (want a radial someday, may be a Stearman), but the new small jet engines made by Williams and P&W seem like the future. If I am burning Jet-A, I personally don't want a prop at all. Cost of Jet engines are coming down and efficiency going up. Of course it depends on what you want to do. Fly high and fast? Go-Jet. Fly low, haul stuff or STOL? Prop. However even the military C-17 jet transport is a STOL plane. Beating the air to death with a prop, whether powered by piston or turbine makes no difference to me, I just want to fly, while not having to sell a kidney. You can by one of those old military jet trainers for less than $100K, but I could not afford the gas bill.


The thing where Greg Richter took an old military Helicopter engine, removing the gear box and turning it into a pure turbojet seems interesting. He talked of fuel burn, range, speed in the article but did not say anything about the cost of engine and installation. It is all in fun CJ; just hanger talk; sorry I don't know anymore about Innodyn, but Innodyn's communication has always been their weak point and their progress does not seem to match their predictions. However they are willing to take your money. George

[cjensen]

i know what you mean about the communication thing from innodyn. i have several emails in to them over the last few months, and only had one returned, and it contained little in response.

i did read that article on richter's cozy. that is a really neat conversion to a jet. 'course he's got the dough...

i'm just an optimistic person (not saying you aren't by any means! ), so i love to think of the promise of turbine (prop or jet) powered machines being within monetary reach someday. may never happen, but i can hope! the small jet engines from williams and p&w are great, but they'll still be too pricey for the experimental market and those wanting insurance (for most anyway).

i just started flying a king air 200 on charter, crew of two. early model, serial number 10! she's a beauty though! new p & i, really nice looking. we've one more trip this week, then she's down for an engine o/h.

btw, innodyn will get no money from me unless they are proven and already shipping, and then only if i can justify it to my boss (wife).

[rv72004]

As much as Innodyne can offer this fantastic engine, I cannot comment.
However a wise man once said "There aint no free lunch"
Yes I would also like to see turbines in our planes, and I appreciate the effort some put into the R&D. Realistically its a long shot.

[gmcjetpilot]

Originally Posted by rv72004

As much as Innodyne can offer this fantastic engine, I cannot comment. However a wise man once said "There aint no free lunch"
Yes I would also like to see turbines in our planes, and I appreciate the effort some put into the R&D. Realistically its a long shot.

The promise of reliability of turbine engines is very attractive even for GA. The issue is when a guy flys 100 hours a year its a little spendy having a turbine "asset" just sitting around. I fly large jets internationally. It amazes me how long and we run these planes; We might do a 12-14 hour flight and layover while the plane goes on (around the world) with another crew, taking it right away for another leg. After that crew gets off their +8 hour flight, another crew brings the same plane back for my next leg. Some times the plane is in the air +18 hours a day for several days, 1/2 way round the world and back. This is all done with only short daily "checks" or ETOPS checks (over water flights). This is where the expense of turbine power is justified. The average GA guy in a personal plane is not really going to take advantage of this kind of reliability. Since engine "failure", true honest to goodness crank shaft, rod poking out the side of the case failures, are rare. A GA guy with a turbine may not be any-less likely NOT to run out of fuel or fly in weather over their head. So the promise of (safety/reliability) of turbines is not really justified by the realities of much higher costs, which I don't think will ever be low. The metals and manufacturing are expensive. As I first said the aura and panache of the whining call of turbines is a strong one, but I think a radial or Merlin sounds better. George

[cobra]

Some interesting comments made.

Why are turboprops desirable? A few things come to mind- excellent reliability, High HP/low weight, and smooth operation.

The downsides: extremely high cost, high fuel burn rate, complexity issues (maintenance, installation, licensing...) , not sized well for our GA application. Possible problems with heat generation and noise.

As a comparison, it seems to me that the Mazda wankel/rotary design has all the advantages of the turbine with none of the problems. The Lycs do almost as well, except for smooth running and a few reliability issues.