Innodyn Turbine Engines

[Jconard]

Quote:

"It's also too bad that the Government can't or won't sue TCM and Williams and get the millions of dollars of taxpayers money back that they paid them for the GAP(general aviation propulsion) program of 1998, of which neither delivered."

I normally don't respond to such, but I must in this case. There are enough lawsuits. Government contractors who do their best, but fail, in a contract for development, have not done anything wrong, and should hence not be sued. You cannot mandate innovation.

This sort of plattitude is dangerous and ignorant...it encourages politically motivated government employees (US Attorneys) to make life miserable for solid aviation companies.

Imgine if a whole fleet of homebuilt and low cost GA planes had turbines. At first it would be great. But after a decade of the typical neglect, and misinformed tinkerings that piston engines endure, the much less forgiving turbines would begin to fail, exposing manufactures to huge liability.

Remember that the airplnes on which those things are so reliable today are fleet maintained using excellent process and practice. Much different from the GA and Experimental market. Remember we had a two week long debate the other month about the necessity of fuel filters!

Then it would be too bad that the government couldn't or wouldn't sue Williams for the defective design of a turbine, which was intolerant of compromised fuel; after all they could have foreseen or anticipated such systems if they sold to the experimental market. Just one example, but it is why Pratt and Williams prefer to supply to sophisticated users.

[Tandem46]

Jconard,

You seem to be making two points, one about the feasibilty of turbines in general aviation, and the other about sueing. I'll conceed that there are far too many lawsuits and I'll maybe even concede your point about the compatibilty of turbines in general aviation. But the fact is our money, US taxpayer money was given to TCM and Williams and they have nothing to show for it. Those two companies took that money knowing full well what it meant and what their part of the deal entailed. (I won't go into the details fo the GAP program here, but there is plenty of it archived on the internet) There would be nothing wrong with the government, on behalf of the US taxpayer, telling them to deliver or give the money back. This wasn't free money for them to do with as they will. TCM really dropped the ball. They won't take their engine to production because they feel there isn't a big enough market. They can't tell me they didn't know that at the time. Companies as large as TCM shouldn't need government incentive money to develop a new engine anyway. They should do it one their own because they want to and because they want to improve their product like every other segment of industry out there but they've been too happy with the status quo for too long. (Lycoming is guilty of this too). You hear a lot of complaints about how aviation piston technology hasn't progressed much in the last fifty years. So if we taxpayers give them millions and nothing changes, then we have every right to demand the money back.

Tobin

[RV_7A]

I received my $100 manual and have to say I was pretty disappointed. Took me about 15 minutes to read completely through it. There is not enough info here to actually install it in an RV. I will be returning it for a refund. Superior XP 360 plus here I come!

[D-M]

I did some research a while back on the Innodyn engine, and I wasn't pleased with what I found.

Innodyn was previously known as Affordable Turbine Power (ATP). It would appear their reputation was somewhat less than spotless.

To anyone who is remotely interested in purchasing an engine from ATP -
Affordable Turbine Power - LISTEN UP!
What follows may save you $10,000 (or more)!
ATP is selling "snake oil" as far as my opinion goes.
Several ********* customers have placed orders and deposits for ATP engines -
and have been the victims of broken promises and outright fraud.
One ******* customer placed a $12,000 deposit with ATP towards a +300hp
version of their experimental turbine - waited to the promised delivery
date - called for the delivery - and was told by the "good" folks at ATP
that:
a. They discontinued development of the 300 hp version of the engine
b. They had no immediate plans to renew development of the 300 hp engine
c. Despite the written order form that guaranteed all deposits would be
escrowed - ATP nevertheless spent his deposit, and
d. They have no plans to refund his deposit.
To add insult to injury, this ******* builder had purchased a constant
speed propeller that works (for all intent and purposes) on a turbine
engine - so he is also "out" the money he invested in the propeller.
This is not an isolated case. Another ******* customer that I spoke with
ALSO lost a substantial amount of money due to the fact that ATP could not
provide an engine and would not return his deposit.


In the last edition of AOPA's ePilot, it had an announcement piece promoting
ATP. I wrote to the editor of ePilot and told him about the fraud this
company has committed and gave him the names of two ******* customers who
were cheated by ATP. The editor followed through - and attempted to reach
ATP for comment. They (ATP) refuse to talk with him. The customers did
talk with AOPA and told them what happened.


One year ago ATP had a booth at Sun n Fun showing their ATP powered RV.
Between SnF and Oshkosh the aircraft added (what is reported to be) less
than 10-hours of flight time. Think about that. 10-hours of flight time in
4-months. If I were selling a new engine - turbine or otherwise - I would
hardly boast about 10-hours of operation in 4-months. Something was (and
is) obviously amiss.


Incredibly, I am contacted by ******* customers who have talked with ATP
... and ATP believe it or not, is giving ******* as a reference! What
balls!


After SnF 2003, ATP went "underground" at last years Oshkosh and this years
SnF. They did not have a booth, but they did promote their "fantastic,
everybody needs to have one turbine engine" at an obscure Cub display. ATP,
you will find, is not in the show program.


These people have the lowest business ethics. If you are fool enough to
give them your money, they are happy to take it.


And that's all I have to say about that.

That alone was enough to put me off buying one, but I was still curious about the technology of the engine itself, so I kept looking.

Apparently the engine is based on the Solar T-62 APU, which was designed for use in a couple of military helicopters and never offered to the general public on the commercial market.

Some information on the T-62 can be found here. In summary, it's an APU designed to operate between sea level and 15,000', run at ~56,000 rpm and produce about 70 SHP.

How they intend to ramp that up to over 200 HP is both beyond me and something I find somewhat scary, to be honest.

Finally, there's a good write up about using APUs as primary propulsion units here. This covers my thoughts on converting APUs pretty well, based on what I learned about them in the classes I took relating to the history, design and operation of gas turbine engines.

Important bits quoted below:

There has been a lot of discussion on the use of modified APU and turbine starters for use in homebuilts here lately. As an engineer in the turbine engine industry, I feel I need to add my own (humble) opinions to this topic. I don't want to sound like some arrogant SOB by saying "I'm an expert, believe me when I say this is realy dumb idea". I hope by giving some background (and I apologize for this post's length) that the readers of r.a.h might get an appreciation of what a complicated problem statement this is and why it is not a good idea.

Adapting an APU to be a turboprop is a much more complex problem than simply designing a new gearbox. Turbine engines are designed for very specific duty cycles. The duty cycle for an APU is very different from a propulsion engine. Running a turbine to the wrong duty cycles can be a recipe for disaster. Here are just a few examples ( and there are many more ) of what can go wrong (I might add, that during my career I have learned many of these lessons by experience):

1) All of the blades and vanes in an engine have natural vibratory frequencies, which when excited result in very high stresses. These natural frequencies can occur in the normal operating range of an engine, and when they do, failure due to high cycle fatigue can occur in a very short time. I was running a vibration survey on an experimental engine and had the compressor shed all of it's blade tips in a very spectacular fashion afte

dwelling on a resonance point for less than two minutes. There are certified engines out there with resonance points in their operating range. For example, an APU may run at two or three fixed rpm's (such as IDLE, No load and Max Load). There could be a resonance point between No load and Max load, but since the engine never spends any appreciable time at that point, there is not much of a problem. However, if you aren't aware of these problems, you might just wind up with your cruise power setting operating at that resonance point with disastrous consequences.

2) A small change in the turbine inlet temperature can have a big impact on the life of the turbine. A rough rule of thumb for current engines is that an increase in turbine temperature of 25F will reduce life by half. You could easily mismatch an engine and get this type of temperature increase. Especially if the engine is controlled by exhaust gas temperature (and most are), you could be extracting more that the design amount of horsepower or operating at some off design condition and the engine would run right up to the EGT limit and but the turbine would see a higher than design inlet temperature with the resulting loss of life (the turbine's life that is).

3) The environment in the engine is very hostile. The temperatures in the turbine can exceed the melting points of the metals and parts are routinely operated into their plastic range. As a result, most of the critical components (disks, blades, vanes, etc.) are life limited due to creep, fatigue or stress rupture. After so many hours or cycles of operation, they must be scrapped. If you don't have any documentation on the engine, you have no idea how much life it has left in it. In some cases, the damage to the parts is not easily detectable, which is one reason the life limits are imposed in the first place.

The energy released by an uncontained disk failure is truly amazing and as I once watched one from the relative safety of a reinforced concrete control room, it still scared the **** out of me.

4) Another thing to consider is that the design and certification requirements for APUs are different that propulsion engines. For example, an APU has a much smaller design "flight envelope", since it is primarily used for ground operation and is not required to operate in some of the more extreme flight conditions that may be encountered. Imagine flying your homebuilt turboprop at 300+ kts through IFR conditions, rain and ice and realizing that the powerplant was not designed to operate in that environment. If an APU failed in such a situation, it would be merely an inconvenience, while the same failure on a propulsion engine would be a little more serious.

I can sympathize with everyone who wants to build a 300 kt turboprop powered plane, it would make one cool cross country plane. But there aren't that many good choices of powerplants.

If you really want to do it (safely), get a certified turboprop engine.

After finding out all of the above, I decided that I not only wouldn't use an Innodyn engine in any project I built, I also wouldn't set foot in any aircraft powered by one. I'm open to experimental concepts and alternate powerplants, but an old surplus military helicopter APU that is probably being run significantly out of design spec is a bit too "out there" for me.

If any of the information above is inaccurate, I welcome corrections. I had to do a bit of digging to find all of this out, and if I can save others from having to do the same or keep them from finding out "the hard way", I think that's a good thing.

Ultimately it's a matter of deciding what best suits your needs, but I'd strongly suggest staying far away from any converted APUs. They just weren't designed with that kind of operation in mind, and no amount of creative engineering is going to change the fact that the engine core was purpose built for a very specific (and different) kind of operation in mind.

[ship]

D-M:
Very accurate. No corrections necessary. Nice write-up. Looked at ATP as a potential investor way back in 2002. Needless to say I wasn't sold. Nothing's changed. APU is recipe for disaster. Fuel claims are totally unrealistic.

[Mel]

I'm not a turbine expert by any stretch, but as a DAR I try to find out as much information as possible and have talked with several very experienced turbine mechanics. They all seem to agree with what you are saying. I have no problem with experimentation, after all that's what we are about. But let's all do a lot of homework in the direction of our experiment.
Mel...DAR

[MarkEsterhuizen]

F1 Rocket C-GKRE 22/22 = 190 KIAS, 10.7 GPH. (55% Power)

[Joe Hine]

Hi Everyone

I read through this topic and there is a lot of information here. I thought I would just add that a friend of mine, just delivered a RV10 airframe to these people that they intend to install one of their turbine engines in and use as a demonstrator. He made sure he was paid for the work before he delivered the airframe.

Joe Hine
C-FYTQ

[RV_7A]

Well its a good thing he is having them do the install because after I received the manual I realized I would have had to be an aeronautical engineer to decipher the installation instructions and apply them to an RV. Until they create a clear installation manual specific to the installation of their engine on an RV along with pictures and details I feel it will be a long time till the RV community warms up to this option.

[ww2planes]

I have watched the Innodyn thread with a lot of interest and I have read a lot of negativity. I hope that this soon changes. The engine is new and they will go through a learning curve. I don't think that Lycoming just came out of the box without some setbacks.

I have found that the people that typically build and fly RV's are good positive people that like to help others. This thread needs to change so that the people of Innodyn can use it to better their product and get support, only if it is moral support.

In my opinion it has the potential to be a wonderful engine and so far, it is the best product for our market that I have seen. At least they are giving an effort in order to provide our category of expirimental aircraft a turbine solution.

Please remember that they are not Lycoming and they never will be. They do have an interesting product that is unlike any other out there. If you are not interested in burning more fuel or using a turbine then just get off of ther backs or show us a better solution.

Lets get off of their case and give them some support. I know that some have had negative experiences with Innodyn but what is not mentioned in the forum is what steps have been taken to help the company improve.

I talked with them and they were very pleasant. If given the chance I would install one of their units in a heartbeat. they are familiar with this forum and they are trying to be a company that will have you knocking down the doors.