Lycoming iE2 FADEC Engine.....whats happening.

[nomorecatering]

3 years ago, with a lot of fanfare, Lycoming anounced their revolutionary fadec controls for piston engines, ther was for a little while stuff published on its development progress..........then, nothing for 2 years.

So whats happened, has it been a failure, not delivering what was promised?

[A and C]

I would guess that they have run out of cash, the Technoligy is quite mature in the auto industry and the uncertified aircraft sector gets much better fuel economy using bolt on bits with Lycoming engines.

So he conclusion is that they have run out of cash or the project or they are about to buy up some other project that is better than the one they had running.

[Jabawocky]

I would like to the data on that, my IO540 BSFC is around 0.39 and I am yet to see any of the experimental bolt on bits do much better if at all. ;) maybe you are comparing their efficient operations with classic old engine manuals running ROP. In which case I can see your perception being realistic.

Truth is a fixed speed engine like a LYC or TCM is pretty darned efficient if operated properly, not how your flying school taught.

FADEC is not really the answer. And when you look at the DA40's you wonder how they were certified when you get a double flame out :uhoh: That is just not meant to happen!

YMMV :ok:

[soay]

FADEC is not really the answer. And when you look at the DA40's you wonder how they were certified when you get a double flame out that is just not meant to happen!
Would that be the incident where they didn't follow the POH instructions regarding starting the engine when the battery is flat?

[Katamarino]

And when you look at the DA40's you wonder how they were certified when you get a double flame out

What exactly is a "flame-out" on an aero-diesel engine, and how does the single engine on a DA40 produce two of said "flame-out"s?

[Brian Abraham]

Jaba means the DA42 (twin engine). As soay says it was all about having a flat battery.you wonder how they were certified when you get a double flame out That is just not meant to happen!It's always going to happen Jabba if pilots fail to operate the aircraft in accordance with the flight manual. Procedures are written for very good reasons.

[FlyingStone]

FADEC is not really the answer. And when you look at the DA40's you wonder how they were certified when you get a double flame out That is just not meant to happen!

It actually is. A good FADEC system on a gasoline piston engine would consist of a good engine monitor (EGT+CHT per each cylinder) combined with ECU which controls the fuel flow, ignition timing, etc. based on the data from engine monitor. I agree, on a good ol' Lyco/Conti in normal cruise you would get almost the same efficiency as in FADEC-run engine, but consider flight with many regime changes (e.g. traffic patterns). Is it really most efficient to run the engine from start to stop with mixture at full rich for traffic patterns at an aiport at MSL? My opinion is no, but you are on a very safe side if you go full rich from takeoff to landing and very lean on the ground - safe, but not as efficient as it could be. FADEC will show great improvement (as it does with diesel engines) in flight training, not that much for touring purposes. You also have to consider the fact that not all pilots are educated about piston engine management as you and that you have many ham-fisters flying around who think mixture is off-on switch, leaning below 5000ft is dangerous etc. FADEC would show greater improvement on engine efficiency (both in fuel and maintenance costs) with them as with you.

FADEC could also be used for making the engine starting more easy, as the ECU does in today's cars, which have crankshaft angle sensor, which senses the position of crankshaft, allowing the fuel to be injected in the correct cylinder in order to make the start process shorter (which is very good for both battery and starter). Modern cars with start & stop even have an ECU logic for stopping the engine at the optimum crankshaft angle, which makes the engine start even faster.

The DA42 accident which you mention is a result of failure to comply with the original (Diamond did modify it to puncuate the possible problem even more) AFM which specifically said that if you start the first engine with a GPU, than you have to be able to start the second one with battery (not GEN/ALT of the operating engine or GPU!) - failure to do that, combined with a unforseen combination of parameters leading the ECU to prematurely feather the props at voltage drop - and bad things happened. But the truth is, every product on the market of any kind has problems - I'm sure even IO540 has had some ADs in the past - they just weren't directed at ECU, because it doesn't have it.

[peterh337]

It's going to be very difficult to improve on the SFC of a "bare" engine running at peak EGT or LOP, with electronic controls, because you are already running stochiometric.

Also there are nontrivial tradeoffs in flying. Let's say you do a "Cirrus" and remove the prop rpm lever. You then for ever suffer worse MPG due to the excessive rpm (friction losses, etc). To reach the operating ceiling you have to go to max rpm anyway (best power). So FADEC would need to make a decision on these things, taking into account altitude for a start, but not just in a simple way to compute the mixture.

[1800ed]

Perhaps FADEC would just make flying easier then. Maybe it could be viewed in a similar way to having a panel mounted GPS, in that it could reduce the pilot's workload?

[dont overfil]

I see a modification has been approved to provide a manual propeller control on the Cirrus models. It is described as an improvement to wear and economy.

D.O.

[peterc005]

A FADEC is a great idea and would be a great improvement on the current 1930's technology we use.

The big advantage is having a "Closed Loop" system, with an O2 sensor in the exhaust governing the fuel injection system to ensure the best fuel/air ratio.

A FADEC would automatically adjust the rate of the fuel injectors to ensure the optimum fuel/ air ratio for changing air pressure situations.

It will be more accurate than manually leaning the mixture and automatically adjust for things like changing altitude.

Basing the mixtue on your ear and the EGT is very crude. this technology has been in cars for 30 years.

[Jabawocky]

Peter,
You need to think that through a little.

Doing all of that is not hard to do, it requires engines to be built or set up after with descent F/A ratios. Simple as that. Next thing is nothing to do with your hearing:ugh:

EGT is a perfectly valid method of setting the required power for the mission.

It is all about "pilot training and standards" and unfortunately the one part not taught properly is the engine bit. In fact it is taught wrong. The text books are wrong. End of argument.

Why don't we build auto aeroplanes that you don't need to fly, sit in a drone and let a computer do it or a kid in front of a pc, you either want to fly the thing or you don't. If you don't get an Airbus:}

PS: if you flatten the battery and fly the lycoming or TCM it keeps running, even if you run a tank dry. So the corrected DA42 manual is so much better :hmm:

[FlyingStone]

PS: if you flatten the battery and fly the lycoming or TCM it keeps running, even if you run a tank dry. So the corrected DA42 manual is so much better

Ever heard that Thielert-equipped aircraft have one or even two FADEC-dedicated standby batteries in the event that alternator starts acting up and battery has been only good to make normal start on a warm day?

Problem is, dealing with FADEC-controlled engines, one needs to adapt. Just as people had to adapt when aircraft development saw transition from tailwheel to tricycle, one has to adapt to new technology. If you can't do it, better fly aircraft without electric system (including starter) or even better - just make replica of Wright Flyer - if they managed to fly, why complicate things, right?

[peterh337]

There is a big difference which is that engine management is hardly rocket science and during 99% of the average flight one never touches the engine controls.

If you had to fiddle with an engine every 5 minutes and/or it needed a PhD, there would be a market for electronic controls. But one doesn't, which is why there isn't.

The Lyco/Conti engines are heat dissipation (CHT) limited at anytime over about 75% of max rated HP, and are heat dissipation limited below that if the airflow is not enough, so a FADEC controller isn't going to be able to do much beyond running them rich during those phases... which is exactly what we do.

There are also so many complete muppets working in GA companies that I would not trust them to design a FADEC which lasts 1/10 as long as my 3 control cables :)

[Silvaire1]

One of my aircraft does indeed lack an electrical system (including starter). It's a great, practical aircraft for the job it has to do, and that job includes lasting a very long time with no manufacturer support whatsoever. Sixty-seven years its been doing the job so far, with over sixty of those year having passed since the airframe manufacturer went broke. I suspect it'll still be doing that when every DA42 ever made is no longer flying.

I have another one too, its been doing a different job for 41 years, with the manufacturer being out of production for 40 of them. The electrical stuff makes it harder to maintain, but with the help of a good A&P, simple technology and very little money it's no problem. It's still getting me into and around complex airspace with its updated in 1988 panel. I plan on flying it more or less as-is for the foreseeable future. Nothing like simplicity to make that possible.

One of the great things about aircraft versus cars and consumer products is that the challenge of designing, building and operating them makes the people really think and do the rational thing. Good solutions last a long time, and bad solutions disappear.

I don't care what idiot European regulators, marketing people, and geeky non-engineer technical 'enthusiasts' think about that, either. I'll be flying my aircraft for the next few decades while they are busy talking :)

[peterc005]

There is an optimal Air/Fuel Ratio and the best way to measure it is an O2 sensor, feeding back into an ECU and then the fuel injection unit.

I guess they had EGT gauges in the 1950's, but not O2 sensors. That is why we use EGT now, not because it's an inherently better way to manage the engine.

[peterh337]

Indeed; the way to do a FADEC is well established.

The huge issue is that car engines are not heat dissipation limited. They are water-cooled and have massive radiators, so you can run them stochiometric at almost all power settings if you want to.

For them, FADEC is perfect. It also helps to meet the emission regs etc etc.

Aircraft engines are made with thin metal sections are and air cooled. Only about half the heat goes into the oil; the other half has to be dumped into the airflow and that isn't terribly efficient. So the constraints are very different, and much cruder.

[Silvaire1]

The huge issue is that car engines are not heat dissipation limited. Heat exchange on high performance aircraft is maximized by raising the temperature delta between the cylinders and the air to the limit of the metal - its more effective to remove heat into ambient air from a 400 degree piece of metal than a 190 degree radiator. Water cooling's advantage is in reducing cylinder temperature gradients and allowing a smaller displacement, high rpm engine... with the attendant weight and efficiency penalty of gearing etc and higher cooling drag.

When you're carrying the vehicle and contents on wings and not by rolling friction, weight is the issue. Aircraft aren't cars.

[peterh337]

True, but you could not run an IO540 stochiometric at 250HP even if the CHT was 500F :)

[Silvaire1]

True, but you could not run an IO540 stochiometric at 250HP even if the CHT was 500F http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

Why would you want to? Max power for climb is a little richer than stoichiometric. Then when you power back and lean for cruise, the cooling design provides enough cooling capacity with minimized cooling drag. What you'd really want to do then is close up the cowling to raise the cylinder temps.

I think that stuff is worked out pretty carefully for going-places aircraft, and meanwhile plunking around aircraft/engines are instead designed to give up a little cruise speed for additional cooling margin.

[Jabawocky]

peterh337
There is a big difference which is that engine management is hardly rocket science and during 99% of the average flight one never touches the engine controls.

If you had to fiddle with an engine every 5 minutes and/or it needed a PhD, there would be a market for electronic controls. But one doesn't, which is why there isn't.

The Lyco/Conti engines are heat dissipation (CHT) limited at anytime over about 75% of max rated HP, and are heat dissipation limited below that if the airflow is not enough, so a FADEC controller isn't going to be able to do much beyond running them rich during those phases... which is exactly what we do.

There are also so many complete muppets working in GA companies that I would not trust them to design a FADEC which lasts 1/10 as long as my 3 control cables

I concurr with most of your post however, the bit I bolded for you is simply not true. I regularly run engines at higher than 75% power, 85+% even and the CHT's are very good indeed, at times as low as 300-310F and at worst 330F. In fact this is cooler than a full rich takeoff. They are done at high power settings Lean Of Peak.

If you wish to run ROP and waste fuel go for it, but if you have CHT problems in a CONFORMING engine then there is a baffle issue.

Otherwise yes a full fadec system is really like having an automatic beer can opener. Cool gadget but really what does it do for the money?

Cars....another problem altogether and why they have BSFC's that are usually worse than our old Lycosaurus and CMI's.

[peterh337]

I concurr with most of your post however, the bit I bolded for you is simply not true. I regularly run engines at higher than 75% power, 85+% even and the CHT's are very good indeed, at times as low as 300-310F and at worst 330F. In fact this is cooler than a full rich takeoff. They are done at high power settings Lean Of Peak.

Yes but only in cruise.

Sure one can cruise at 100% power - 165kt IAS for me, and loads of airflow.

23 USG/hr :)

[FlyingStone]

Cars....another problem altogether and why they have BSFC's that are usually worse than our old Lycosaurus and CMI's.

Apples and oranges.

Cars need to conform to very strict emission standards, whereas aircraft don't. I haven't seen an aircraft with even a catalytic converter, let alone any specific design feature, such as increasing fuel flow to lower the combustion temperature to maintain NOx emissions within limits, etc. Primary objective in an aircraft engine is reliability, but for a car engine, reliability is not such a concern (as long as it lasts until the end of warranty), but the COx, NOx and diesel particles emissions - and of course fuel consumption - are of much greater significance.

Try to achieve modern emission standards with 60-years old Lyco/Conti design and then compare BSFC. You're in for a shock.

[Charles E Taylor]

This is a big task.

To certify a closed loop digital engine control - power control to Do178C level A and Do160 and Do254 is not a trivial undertaking.

Particularly when it is intended as a generic controller.

In the volumes likely to be sold, the controller might well cost more than the engine.



Tough job.



Charlie

[ploucandco]

Rotax recently certified their 912is -> 912isc with fully electronic and redundant fuel injection system and engine management system. EASA Certifies Rotax 912 iS (http://www.avweb.com/avwebflash/news/EASACertifiesRotax912iS_207234-1.html)

Maybe Lycoming needs to be purchased by a chinese company (like many other US GA companies) to move ahead...

Jacques

[nomorecatering]

Would be interesting to see a 6 cylinder 160 hp iS Rtoax engine developed.

[Dross61]

Leaded AV Gas kills O2 sensors. That's why we use EGT.

[Dross61]

A FADEC will deliver more power on takeoff than just manually setting at full rich. Full rich is NOT full power.

Also a FADEC system provides a lot of diagnostic data and reams of digital data. We once told a customer which plug, bottom cylinder 4 was loose. Someday warranty will be based on FADEC history data.

And yes a great pilot who understands his engine can run it just as well, while doing a thousand other cockpit task, but those pilots are few and far between. Exceptions taken for this forums readers.

A FADEC system will help prevent over heating by enriching the mixture to a cylinder that is overheating. The TCM system could adjust the mixture for each cylinder independently, a different mixture for each cylinder giving a very smooth running engine.

[Lumps]

why is there nothing on the web about these engines??!

[Lumps]

On the Lycoming iE2-tt540 powered Evolution EVOP-350 website max cruise 28GPH 230KTAS, economy cruise 16GPH 200KTAS.

I'm going to assume the max cruise FADEC setting is very ROP (hopefully, assuming Lycoming's computer programmers are not the same mob that have been promoting 'best power' all these years)

Also the economy cruise, given say an 8:1 compression ratio (too generous?) looking at around 75% power if it was LOP

So it doesn't add up quite, what % power is 28GPH?

Anyone able to shed some light?