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Would you consider FADEC?

Hypothetically if you were selecting your engine right now, would you consider FADEC?

  • Never! I learned to fly with mags and a carb or mechanical FI, and I'll never trust anything else.

    Votes: 9 4.5%

  • Nah... I've warmed up to electronic ignition, but electronic FI still gives me the heebee-jeebies.

    Votes: 18 8.9%

  • Maybe some day. Sounds good, but I'd want to see more of them flying before I'd take the plunge.

    Votes: 41 20.3%

  • Maybe if the price is right. Sounds good, but it needs to come down in initial cost.

    Votes: 83 41.1%

  • Heck yeah, give me! I love the benefits, and I'm willing to pay for it. Cheaper in the long run.

    Votes: 47 23.3%

  • Other. What did I miss?

    Votes: 4 2.0%
  • Total voters
    202
R

roee

Well Known Member
For many years now, the majority of modern automobile engines have had computer-controlled ignition and fuel injection. The benefits are many: easier starts, smoother running, better performance, better fuel efficiency, better reliability, and built-in self-monitoring and diagnostics. In the aerospace world, this same technology is known as FADEC (Full Authority Digital Engine Control), and offers all the same benefits as it does in a car, plus it reduces pilot workload by eliminating that ugly red mixture knob. The drawbacks are few. Mainly, FADEC does make the engine electrically-dependent, so electrical system redundancy is required. But electrical system redundancy is becoming commonplace anyhow as glass cockpit technology becomes pervasive, so these technologies go together nicely. Also, FADEC is still more expensive than traditional ignition and fuel injection to install, but the initial cost is offset by reduced operating costs: fuel and maintenance.

There have been FADEC products for Lycoming-style engines available to us for some time, but it seems that only a few of us have adopted the technology in our RV's. I have been planning on installing a FADEC in my RV-7A, but sadly, one of the most promising FADEC systems that I've been interested in is as of recently no longer being offered to us by the manufacturer, reportedly due to lack of demand. I would think that we RV builders should be a big potential market for this technology, and yet so far we haven't embraced it. I'm very curious to know exactly why, so I present the following poll to the group:

Hypothetically, if you were selecting your engine right now and weighing your options, would you consider FADEC?

1. Never! I learned to fly with magnetos and a carburetor or mechanical fuel injection, and I'll never trust anything else.

2. Probably not. I've warmed up to the idea of electronic ignition, but electronic fuel injection in an airplane still gives me the heebee-jeebies.

3. Maybe some day. I could appreciate the benefits, but I'd want to see more of them flying before I'd take the plunge myself.

4. Maybe if the price is right. I could appreciate the benefits, but it needs to come down in initial cost for me to consider it.

5. Heck yeah, give me! I definitely appreciate the benefits, and I'm willing to pay a premium for it. I know it'll save me money in the long run.

6. Other. What did I miss?
 
Happy flying it

We now have about 110 flying hours behind a Fadec under all kind of conditions, quite hot temps and, like today, -10 deg C. In all this conditions we never had problems starting the engine, always good temps and virtually no oil consumption after break-in. Our engine is praised by very experienced mechanics for its smooth running. Fuel consumption is modest (33L/hr), power is more than plenty. Personally I'm very happy with the detailed datastream from the RS232 serial bus controller which is fed nicely into our VM1000C. After our initial Theething Problems we've had no trouble at all. All in all I think it was a good choice but to be honest maybe I would have enjoyed a more conventional engine as well.
We had some issues setting up the system, mainly because of the lack of a GOOD manual, but so far Mahlon Russell and Jabe Lutrell were very helpful and advised us very good. Now TCM has stopped producing for the experimental market, I hope there will remain people or companies available should we have serious problems.
 
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Roee,

Good poll.

There are a lot of people who won't run with electronic ignition, let alone FADEC. Heck, just look at the problems ALL the EI makers have had and they don't even need to certify them for our market. Can you imagine the challenges a FADEC designer would face?

If someone came out with a FADEC that would work, including a knock sensor, which I understand is the biggest hurdle due to the size of the power pulse on our slow turning, big boor engines, I would be all over it. Porsche tried this in the Mooney back in the 80's and gave up. I wonder what happened to those planes. Here?s a link.

Maybe someday we will see it.

One of the advantages of FADEC in a car is the rapid change in operating environments a car experiences. Where a plane takes off, climbs, sets power and cruises, descends, and lands. A car will change power settings many times and may climb up and down in altitude, the electronics are perfect for this. I think that is why you haven't seen a real push for aviation FADEC in anything other than helicopters.
 
Personally I love electronics on my car. Used to work on fuel injection systems, Bosch, GM, Ford etc. I guess for me it comes down to nostalgia and bang for the buck. The airplane I am flying now is a Baron. I like those six levers. FADEC's cost a lot with out a lot of extra performance. I guess I would like to spend my money some place else, like a paint job or a new Garmin. I heard of a FADEC airplane that had a dead battery. The pilot got a jump start and went flying. Everything was fine until he went to put the gear up. The voltage dropped to the point that the FADEC quit and the engine died.
 
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Several issues

Including the inability to manually adjust the mixture. Running lean is extremely important for fuel economy and overall efficiency.

For me the major issue would be hot starting. Lets see how it would work in 115F or 45C. I don't think it could handle it.

I love new stuff but there is really no significant advantages. The disadvantages begin with cost and complexity.

Just some thoughts.
 
I saw a FADEC system on a 7A. Thoughts were that it was too much weight and complexity. Problems during the flying test phase may have been partly due to the FADEC or fuel injection system. The plane later had a engine performance problem, landed off airport and was totaled. Most people here initially assumed that the FADEC was the source of the problem. Not for me.
 
Rene Bubberman said:
Now TCM has stopped producing for the experimental market, I hope there will remain people or companies available should we have serious problems.
Click to expand...

That might explains why the http://www.fadec.com website is gone from DNS. What's up with that decision? it seems like a bad time to be reducing market coverage, although their (ex) competition must be thrilled. Any reasons you know of?
 
What

are its failure modes?

What happens if an injector goes down?....Are they automotive injectors with a long history and have they been fully tested?

To me Fadec is a bit like an automatic gearbox on a car...I.e are you a driver or a passenger hoping for the best?

Personally I like playing mixture control like a tromone much to the amazement of my spam can rental flying passengers..:)

Frank
 
My professional expertise is in electronic engine control and I have worked developing many systems over the last 15 or so years. In fact I spent '06-'07 in India designing and developing (and demonstrating how to) a clean sheet engine controller for a large motorcycle manufacturer there.

I have often looked at the FADEC challenge and I'd love to give it a go one day, but the chief thing that makes me hesitate is economics... The volumes may or may not be there to amortise the development costs and that uncertainty is what tends to kill it, IMO.

It's comforting to see that a majority will consider it at the right price, but by no means is it a marketing certainty. Look at the dismal penetration of the (albeit a bit ordinary!) Aerosance products for an example of what could happen.

As far as operation, safety and reliablity, unquestionably it could be made to better than six-sigma reliability and "perfect" cold starting, altitude operation and optimum fuel consumption are a given. (BTW, LOP operations become meaningless as soon as you fiddle with the igniton angle - there is no need for a mixture knob - really! :))

The most difficult stumbling block is sourcing hardware on a commercial basis - fuel injectors, sensors and actuators that please both the FAA and the suppliers. Most automotive OEM's are dead scared of the product liability implications for the dismally low volumes of the piston engine market, so you have to find devious ways of sourcing stuff - which the FAA are not going to like!

One day it will happen, but a lot of things will have changed by then...
 
Hot or cold starting is no problem with EFI once it is all tested and programmed properly.

At the quantities required for the aviation market, injectors and other fuel hardware is readily available from hundreds of vendors. Supply is not a problem.

I agree with Andy, no need for a red knob once everything is programmed and tested. The FADEC will do a better job than a human over the course of startup, taxi, climb and cruise. Always optimized for best power and lowest fuel flow.

IMO doing fuel injection is actually less work than EI. Many of the problems with the popular aviation EIs are due to lack of testing in my view plus some questionable design work as well. Heat and moisture need to be managed with electronics and some vendors in this field do stuff that would never pass first review in the automotive world.

One of our clients is about to start flight testing a low cost experimental EI/EFI setup for Lycoming 4 cylinder engines. I don't think there is a big market for $6K+ FADECs in the experimental world.

With the success of one of our other clients in Reno Super Sport Class last year using EI/EFI, many others are suddenly interested in the advantages it offers over conventional controls- especially in this high workload environment.
 
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N941WR said:
I think that is why you haven't seen a real push for aviation FADEC in anything other than helicopters.
Click to expand...

Just about every new-design aviation turbine engine, whether it's turboshaft or turbofan, is FADEC-equipped. Even the majority of "growth" engines are FADEC'd in the upgrade process (example - CFM56).
 
Price vs. Reliability

I find it very interesting that almost 50% of the voters are interested in price, and less than 18% are concerned with reliability.
 
I think many have expressed concern with reliability by saying they wouldn't buy until many tens of thousands of flight hours prove they are reliable- rightly so.
 
Flying W/ FADEC

I can say that I like flying an aircraft with FADEC. I never liked messing with the mixture control. I prefer to start it up and go flying. I have not had problems with fowled plugs (too rich) or burned pistons (too lean). I get good gas mileage and plenty of power at all altitudes and I don't have to think about it. Would I use FADEC again on another airplane? Probably, but it's not a slam dunk either. Aerosance is out of business and future support is in question. If Lycoming came out with a system, I would definitely give it a look.

Dane Patterson
RV-8 w/ IOF-360
 
Exactly...

rv6ejguy said:
I think many have expressed concern with reliability by saying they wouldn't buy until many tens of thousands of flight hours prove they are reliable- rightly so.
Click to expand...

I have no doubt that a reliable FADEC could be engineered. The problem is how does the manufacturer recoup the money spent on the engineering and testing? The market is so small and the development costs so big that no one with any business sense is going to take the risk. This leads to people trying to produce the product without the capital and development required and then sell it "before its time."

Personally, in my slightly "steam gauge" mind there is another issue. I like to be involved in the process when I am operating a vehicle for fun. As much as I admire the seamless performance of my Audi A4 with it's electronic engine controls, I much prefer my old Alfa Romeo for a sporting drive. It "needs me" the Audi doesn't. Same with aircraft. When I was flying turbines for a living I was very fond of all the PFM* that made my job easier but for fun, I enjoy doing some manual engine management.

(* Pure Flaming Magic) :D

John Clark
RV8 N18U "Sunshine"
KSBA
 
I did, sort of....

I went with the Eagle EMS from Precision Airmotive. They are the manufacturers of the SilverHawk fuel injections along with a Bendix clone for the certified market.

The Eagle encompasses dual electronic ignitions and electronic fuel injection. It does NOT control the prop. It eliminates the hot starts and constantly adjusts the fuel mixture for all phases of flight. If you are really wanting to run lean, you can manually lean by an additional 10% using the supplied small dial.

I bought my system from Aerosport who is the most knowledgeable about the system and have done several builds and tests on this 320s, 360s, and 390s. It cost me $2,500 more going this route vs the typical mag/light speed and Silverhawk installation.

It contains all the backups that one would expect. It does require it's own battery backup for which I use a small 3.6 Amp Hr battery that the Eagle will monitor and maintain. The Eagle uses 1.6 Amp per hour, so that gives me a couple of hours of runtime, which is plenty to find a place to land.

Hope to be flying by June.
 
Andy_RR said:
As far as operation, safety and reliablity, unquestionably it could be made to better than six-sigma reliability and "perfect" cold starting, altitude operation and optimum fuel consumption are a given. (BTW, LOP operations become meaningless as soon as you fiddle with the igniton angle - there is no need for a mixture knob - really! :))
Click to expand...


can you explain how that works (not needing lop if you can adjust ignition angle) in a short post for someone that doesn't know what you are talking about?
 
I'm interested too!

Danny7 said:
can you explain how that works (not needing lop if you can adjust ignition angle) in a short post for someone that doesn't know what you are talking about?
Click to expand...

I am looking forward the the explanation too. The fuel mapping that I have seen on EFI engines goes very lean of peak when conditions are right.

John Clark
RV8 N18U "Sunshine"
KSBA
 
LOP?

Most mag-ignited aero engines run with a fixed ignition angle, starting with impulse mags notwithstanding.

LOP is merely a means of finding a quasi-optimum mixture point for the the fixed speed and ignition parameters you have.

If you can change the ignition and the mixture, then the FADEC will probably always run the engine lean where EGT, CHT and other temperature limits allow. (Automotive engines don't do this generally because of emissions control constraints which don't apply to aero engines)

For any given engine speed and power requirement, there is a manifold pressure, ignition angle and mixture setting point that produces the optimum fuel consumption. You pick the MAP with your throttle and the FADEC will control the fuel and ignition to reach this point. EGT then becomes an irrelevance for the pilot (note I did not suggest the pilot ignores CHT!) and he can then spend more time looking out of the window

The same thing will happen for cold starting, hot restarting etc. Electronic fuelling and ignition control allow very fine tuning for virtually perfect first-time starting
 
Cost/Benefit Ratio

Most mag-ignited aero engines run with a fixed ignition angle, starting with impulse mags notwithstanding.
True

LOP is merely a means of finding a quasi-optimum mixture point for the the fixed speed and ignition parameters you have.
There is a lot more to it than that. I suggest you Google John Deakin and read the many benefits of LOP.

If you can change the ignition and the mixture, then the FADEC will probably always run the engine lean where EGT, CHT and other temperature limits allow. (Automotive engines don't do this generally because of emissions control constraints which don't apply to aero engines)
"Probably run lean?" No, it will due whatever it was programmed to do.

For any given engine speed and power requirement, there is a manifold pressure, ignition angle and mixture setting point that produces the optimum fuel consumption. You pick the MAP with your throttle and the FADEC will control the fuel and ignition to reach this point. EGT then becomes an irrelevance for the pilot (note I did not suggest the pilot ignores CHT!) and he can then spend more time looking out of the window
Not really. In a true FADEC (Full Authority Digital Engine Control) you are not going to have a "throttle" you will have one lever to select the power output, not MAP. A true FADEC controls all the engine parameters including RPM (prop). None of this is new, it was done on the Porsche Flugmotor used in Mooneys and a few Cessna 182s.

The same thing will happen for cold starting, hot restarting etc. Electronic fuelling and ignition control allow very fine tuning for virtually perfect first-time starting
Very true, it would be the answer to hot starts.

My issue with a complex FADEC in a small piston aircraft is the cost/benefit ratio. Unlike an automobile engine we are running aircraft engines in a narrow RPM range (400-500) other than idle and not asking the engine to produce torque at very low RPM, as you might in a manual gearbox car. So, since the original question was "Would you consider FADEC," my response would have to be no. With the cost of the technology, the required backups to support it, and the complex diagnostic and repair issues I doubt will ever be covered by the small fuel savings.

John Clark
RV8 N18U "Sunshine"
KSBA
 
John Clark said:
LOP is merely a means of finding a quasi-optimum mixture point for the the fixed speed and ignition parameters you have.
There is a lot more to it than that. I suggest you Google John Deakin and read the many benefits of LOP.
Click to expand...

No John, it is really just that. Anything more to it is making it unnecessarily complicated. I know there are "many benefits" but really all you are doing is minimising BSFC for the speed and power you want. The LOP method is the way of reaching that operating point. My original point was that "Lean of Peak (EGT)" makes no sense when you are optimising both fuel mixture and ignition angle.

John Clark said:
If you can change the ignition and the mixture, then the FADEC will probably always run the engine lean where EGT, CHT and other temperature limits allow. (Automotive engines don't do this generally because of emissions control constraints which don't apply to aero engines)
"Probably run lean?" No, it will due whatever it was programmed to do.
Click to expand...

Yes, I know it will do what it's programmed to do, but under all conditions where it is not EGT/CHT limited, it will (probably) be programmed to run lean, where the best BSFC point lies.

John Clark said:
For any given engine speed and power requirement, there is a manifold pressure, ignition angle and mixture setting point that produces the optimum fuel consumption. You pick the MAP with your throttle and the FADEC will control the fuel and ignition to reach this point. EGT then becomes an irrelevance for the pilot (note I did not suggest the pilot ignores CHT!) and he can then spend more time looking out of the window
Not really. In a true FADEC (Full Authority Digital Engine Control) you are not going to have a "throttle" you will have one lever to select the power output, not MAP. A true FADEC controls all the engine parameters including RPM (prop). None of this is new, it was done on the Porsche Flugmotor used in Mooneys and a few Cessna 182s.
Click to expand...

Yes, I am not precluding prop control in FADEC operation. By your definition of FADEC you will need electronic throttle control, which is both heavy and expensive to engineer. I doubt (but I'm not 100% sure) that the PFM3200 had that either, since such devices were still being looked upon with great suspicion even in automotive circles.

You could label the knob as % power if you wish, but ultimately it is cheaper and arguably better for this application to have it pulling on the throttle valve.

John Clark said:
My issue with a complex FADEC in a small piston aircraft is the cost/benefit ratio. Unlike an automobile engine we are running aircraft engines in a narrow RPM range (400-500) other than idle and not asking the engine to produce torque at very low RPM, as you might in a manual gearbox car. So, since the original question was "Would you consider FADEC," my response would have to be no. With the cost of the technology, the required backups to support it, and the complex diagnostic and repair issues I doubt will ever be covered by the small fuel savings.
Click to expand...

I'm not going to argue with your conclusions, except to add that the cost of the technology may not actually be that high - it's just the return on investment is uncertain. Add up the new cost of a mech FI or a carb and mags and see how much you've spent!

Diagnostic and repair information is improved with electronically controlled devices in the automotive sector. The people who tell you otherwise I will call luddites who usually refuse to understand how it all works.

Fuel savings may (or may not) be small, but they will become critical when leaded AVGAS is substituted by lower octane unleaded fuels. Converting to ULG in the auto industry is part of what spurred development of electronic control and, if you "normalise" the data, has delivered dramatic fuel economy and performance improvements compared with what the world was driving 20-30 years ago. The same thing could happen for piston aero engines, but this actually happening is not at all a certainty.
 
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Mel said:
I find it very interesting that almost 50% of the voters are interested in price, and less than 18% are concerned with reliability.
Click to expand...

I don't personally require a 20 year track record before I'd be convinced. I'd hope the reliability is a bit north of the E/P mags, but that's why I voted for price. I view electronics as far more reliable than any mechanical device so I have no trouble with them being paired down in redundancy. Some sort of watchdog to monitor it and perhaps provide a limp home mode would be fine.

But then I'm a young whippersnapper who grew up on Atari and barely remembers cars without EFI. The only carbed / mechanical car I drove was a Chevette, and if you drove one you'd want to forget everything about it too! :D
 
No luddite...

I spent 15 years working for Mercedes Benz and am familiar automotive fuel and ignition systems. As I stated, my questions are about cost/benefit not the technology. In fact, my RV8 is a little tiny bit ahead with a Lasar ignition system. And yes, it runs a little smoother and burns a little less fuel due to the variable ignition.

The single thing that would push light piston airplanes into less than stone-age technology would be emission rules. In the US of A the powers that be have already passed regulations regarding gasoline lawn mowers, so we can't be far behind. I laughed at Shockwave's reference to a Chevette (Holden Gemini to those in Oz). Yikes! That was the height of the auto industry trying to make old technology pass modern emission standards.

I once flew a Porsche powered Mooney and it did have a single lever engine control, but I have no idea how they accomplished it. I doubt, as you do, that there were servos involved.

John Clark
RV8 N18U "Sunshine"
KSBA
 
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There is a world of difference in what is being developed for the certified market by Lycoming in the form of IE2 and what presently exists for experimental engines. This revolves mainly around cost vs. redundancy requirements set by the FAA. Clearly, we don't need all this for reliable electronic engine controls for experimentals and the costs that goes along with it.

IE2 is an awesome system and near state of the art even compared to the latest automotive systems but the wiring harness alone costs more than a complete system available for experimentals (minus the propeller control). I was able to talk to some of the techs developing IE2 and their initial target is for high end airplanes, not RVs. There was interesting discussion about IE2 making reliable, powerful turbocharged piston engines a reality and a valid competitor to small gas turbines. Eliminating the ham fisted pilot pulling the levers and causing premature problems with IE2 was seen as a way give high output turbo engines a better reputation. You can't over temp, over torque or over boost it so it actually lives.

In a steady state condition like aircraft engines generally operate under, FADECs probably offer little advantage in fuel flows during cruise compared to a savvy human with proper instrumentation to set LOP. FADECs show more gains outside the cruise range and especially so on turbos which may have to run on lower octane unleaded avgas in the future. The FADEC monitors everything important simultaneously and adjusts for max efficiency constantly while keeping the machinery within safe limits.

Until we get something like BMW's Valvetronic system, gasoline aircraft engines will continue to have a throttle plate controlled directly or indirectly by human hand to set power.

Well designed and tested electronics are certainly more reliable than the mechanical systems they replace or are attached to as one poster stated. Diagnostics are way easier with electronics compared to legacy hardware. Costs need to be reasonable before you'll see a lot of the old guard switch however.

It takes a lot of convincing sometimes to trade our VORs, maps and steam gauges in for GPS and glass and letting go of that red knob to have a microchip do the work. FADECs will never be for everyone but for those open minded enough to take the plunge, most see the light and are quickly converted. Some day, FADECs will be nearly as common on higher end piston engines as they are now on most gas turbine engines.
 
I still feel that an educated pilot and a well monitored engine will be more reliable than a FADEC system (and so far I've been right from the limited exposure I've had to the TCM FADEC system). Someday it may be viable, but for now tune those injectors, get a single EI, and run LOP.
 
rv6ejguy said:
It takes a lot of convincing sometimes to trade our VORs, maps and steam gauges in for GPS and glass and letting go of that red knob to have a microchip do the work. FADECs will never be for everyone but for those open minded enough to take the plunge, most see the light and are quickly converted. Some day, FADECs will be nearly as common on higher end piston engines as they are now on most gas turbine engines.
Click to expand...

I still prefer the benefit of my Lyc being totally independent of the aircraft's electrical system. I traded in the VORs many years ago, use a 696 because I'm a GPS "junkie"; yet I have no desire to get rid of the "red" knob.

L.Adamson --- RV6A
 
RichB said:
That might explains why the http://www.fadec.com website is gone from DNS. What's up with that decision? it seems like a bad time to be reducing market coverage, although their (ex) competition must be thrilled. Any reasons you know of?
Click to expand...

Talked to Teresa (Theresa?) at TCM yesterday about this. Aerosance developed their FADEC system as an independent company, and had been allied with TCM for several years now. Aerosance gave it up, and the program has now been brought in-house at TCM, where the whole system is under review. They have quite a few of the factory IO-240 FADEC controlled engines out in the field, particularly in Australia, in addtion to the RV installations, and are not getting out of the FADEC business at this time. Future availablity of aftermarket systems for Lycomings is unknown at this time, but has not been ruled out. We'll see.
 
I like the challenge of flying...

... take my knobs away, and part of the interest and fun just went away. I found myself playing with my power and mixture settings a lot at first, and still some today, just to verify what is supposed to be happening in my own mind against what the manual says.
Also, I just like to play with knobs!
 
fadec in experimentals/homebuilt

thanks for the interesting read.

A helicopter has been on my list since I was a kid, and I've followed Rotorway over the years.

The later Exec and now the Talon use redundant FADECs.

http://www.rotorway.com/fadec.html

---------------
If I was happy with the failure and fallback modes, the service record and the price, I'd strongly consider using a FADEC. For me, storage/service temperatures are very interesting, as well.
 
The only thing that keeps a fadec system form being produced is LIABILITY, companies can't even get insurance for producing 1900's technology (carbs) it would be a pretty foolish business model to try to develop a system knowing that the line of ambulance chasers would be just waiting for the first crash. The technology is available, the need is there, it would take a brave company to assume the risk.. just my opinion
 
rvator9a said:
The only thing that keeps a fadec system form being produced is LIABILITY, companies can't even get insurance for producing 1900's technology (carbs) it would be a pretty foolish business model to try to develop a system knowing that the line of ambulance chasers would be just waiting for the first crash. The technology is available, the need is there, it would take a brave company to assume the risk.. just my opinion
Click to expand...

The technology is not only available, it's in production. One company has been making FADECs for certified pistons engines for a number of years now and Lycoming will soon be releasing its IE2 engine line which are FADEC equipped. Liability concerns were not a deciding factor here since these systems are or soon will be in production and use. Several other companies use FADECs on their engines as well, notably Thielert and Rotorway.

Vendors for products destined for the experimental market may have liability concerns but there is far less likelihood of a successful lawsuit being brought in this market IMO. However, anyone can be sued for almost anything!
 
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liability

To some extent, the liability is a complete non-issue for the incumbents. In fact FADEC would reduce their liability, not least because the risk of carb-ice related incidences would diminish.

The liability issue does scare off newcomers though - I know this because I've tried to convince some who could do it well to entertain the FADEC idea and the answer is a firm "no thanks"

A
 
Not really needed

Unlike cars, aircraft engines spend most of their time at a steady power setting. The efficiency benefits of FADEC in cars simply is not as great in aircraft. After you fly your RV for many hours, you will know where to put the knobs at first power reduction. After that, fine tuning is all that is required as you change altitude.

Most engine and prop combinations have a sweet spot where operation is the smoothest. In the Doll that is 2350 RPM. I used that RPM 99% of the time while in cruise. If the Doll were FADEC, the computer might select a different RPM that might be slightly more efficient, but not as desirable, and I would have no way to change it.

I use LASAR ignition so I have the best of both worlds for ignition. LASAR gives you the benefits of electronic ignition with the complete independent backup of dual magnetos.

I have never had any problems starting my I0360 A1B6 hot or cold. Once you learn your engine, starting is easy. IMHO FADEC is not worth the cost and complexity for homebuilt aircraft.
 
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Yes, I've mentioned this before, in cruise, gains are minimal. We find most of the lower fuel flow happening in the start, taxi, takeoff and climb rather than cruise.

On turbocharged engines, the gains are larger due to both fuel and spark being optimized collectively. Independent EIs can't match integrated systems in this respect since they don't know what the pilot is doing with mixture.
 
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Perhaps the gains/benefits are greater for low time pilots, and for aircraft that get rented back to clubs, or with shared ownership. Knowing the next guy to fly your plane won't be wasting gas or mistreating your engine has got to be worth something.
 
disagree with the "not really needed" view

It's true that aero engines run quite efficiently in the cruise when operated LOP with a full engine monitor etc, but I think that's missing some of the point. I think of FADEC as an enabling technology, where you could run MOGAS (or unleaded AVGAS) at 9.5:1 compression ratio with complete safety. When you start doing that things like that the fuel consumption benefit starts to grow fairly significantly, even in the cruise.
 
Great discussion!

Wow, I'm really pleased at the response to this thread and poll! We got a great discussion going with many points of view, and learned a lot about FADEC, and about people's perceptions of FADEC.

I'll try to summarize, and respond, to some of the key topics that came up so far in this thread. Now, I won't claim to be impartial. Clearly I'm a proponent of FADEC, as I've said before. So my responses are just my point of view. Feel free to disagree ;). The following "quotes" are not really quotes, they are paraphrased by me:

1. "I actually enjoy manual engine management, like twiddling with the mixture knob" or "having a mixture knob invokes pleasant feelings of nostalgia".

If that's how you feel, I certainly can't argue with that. We all find enjoyment from different aspects of flying, and that's just fine. Enjoy!
​

2a. "A well trained pilot should be able to adjust the mixture as well or better than a FADEC".

That, with all due respect, is simply not true. A well-designed FADEC system could adjust the mixture far more optimally than any human pilot (yes, even one as good as you :)), individually per-cylinder, and fine-tune it continuously, literally on a cycle-by-cycle basis.
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2b. (corollary to 2a) "It won't let me manually adjust the mixture."

Right. Neither will your car, and it seems to run pretty well. You don't need to adjust the mixture manually because the FADEC can do it better than you can, no offense. Unless you simply enjoy manually adjusting the mixture, which is fine (see number 1).
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3. "A FADEC may be beneficial for newbies, but not so much for experienced pilots."

It's not just about how proficient you are with the mixture adjustment. Even if hypothetically you could manage the mixture equally well as a FADEC (in your dreams :)), one of the most important benefits of FADEC, in my view, is that it simply removes much of the tedious aspects of engine management from the pilot's workload. It does the mundane repetitive tedious stuff (the stuff computers can do better than humans anyway), so that you don't have to. The FADEC allows the pilot to monitor and manage the engine at a higher level of abstraction, and therefore leaves more of the pilot's time and attention to devote to other aspects of the flight (navigation, traffic, etc.). That's a good thing even for the most experienced pilot. Reduced task loading, increased situational awareness, increased safety.
​

4. "FADEC is more complex than traditional FI and mags."

Well, there are different kinds of complexity. It's a trade-off. FADEC systems are much more complex electrically. That is true. But most of that complexity is handled by the engineer who designed it, not by the airframe builder, and not by the pilot. FADEC systems are far less complex mechanically, with very few moving parts, which is a key factor in their potential for better reliability than the traditional systems. FADEC is also far less complex operationally for the pilot, as I discussed above.
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5. "Look at the problems some of the electronic ignition products have had."

Yep. Just because a technology is fundamentally sound, doesn't mean that every product on the market will be sound (this is true with any technology). Without going into specifics (no vendor bashing here), some of the troubles in the EI arena seem to have been the result of shoddy engineering practices and/or lack of sufficient product testing by some of these vendors. In the experimental market especially, some products are designed by highly qualified professionals, while other seemingly similar products are designed by not-so-qualified dabblers and tinkerers. Sometimes the results are still very good, sometimes not. It really depends on what the individual was willing to put into it. Some vendors are also more forthcoming than others about what they've done and what they haven't done to ensure the quality and robustness of their product. Ultimately, the freedoms we have in building experimental aircraft also come with a responsibility to ourselves to do our homework and make educated decisions about what equipment we install in our aircraft. Not all EI's are created equal, not all FADEC's are created equal. Insist on a product that has demonstrated its merit to your satisfaction.
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6. "FADEC is too expensive."

Yes, it is still significantly more expensive than the traditional systems. Presumably, reduced operating costs over the life of the airplane would offset at least some of that initial investment. But still, yes, that's a lot of extra $$$ to fork upfront, and for many of us (about 40% of us according to the poll), that has been the deal breaker. It's the classic catch 22 for the vendors. To bring the cost of a product down, the vendor has to sell a greater volume of units. And to sell a greater volume of units, the vendor has to bring the price down. It seems that with Aerosance, the gap was just too big for the product to reach a viable critical mass in our market, and so they finally gave up. But what our poll shows as sort of an informal market survey is actually very encouraging. It shows that if the price was lower by a sufficient amount, over half of us would buy it. Last year 600 new RV's flew, so if this poll is representative of the group, that's potentially 300 FADEC units per year. That's more than Aerosance has sold, ever. I'm hoping, since the demand apparently is there, at least at some price point, that Aerosance/TCM and/or other vendors will try again to have a go at it in the future.
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7. "It's cost and/or liability that keeps companies from developing FADEC products."

Well, Aerosance did it, and others are doing it.

It takes time and money to develop a product. But once that's done, it can be manufactured for a pretty low unit cost if you make them in sufficient numbers. A FADEC system in principle could be manufactured even less expensively than the traditional systems, because it's mostly generic electronics (cheap!!!) rather than specialty mechanical parts (expensive!!!). For things like coils or injectors, it can leverage from the automotive market, which has made these parts relatively inexpensive too due to high volumes.

As for the threat of liability, that concern is always there for anything and everything having to do with aviation. Still, many courageous businesses thrive in aviation, and they do what they think is necessary to protect themselves legally. The liability issue is a pain in the a**, but it's not insurmountable.
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8. "Anyway, so Aerosance is out for now, what else is out there?"

Well, there's Lycoming's iE2 on the horizon, although it sounds like they'll be targeting it only for their bigger engines, at least initially. There's also the Eagle EMS from Precision Airmotive, which I'm looking forward to learning more about. There may be other products, I certainly don't mean to exclude if there are. I personally have just been focused on Aerosance for some time, so now I'm back to the drawing board and re-investigating what's out there.
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Great stuff!
 
Pretty fair summation from where I stand (15 years in this field). Hopefully some much lower cost units will be available in the next 12-18 months for the experimental market.
 
I agree with pretty much every point, with one addition:

roee said:
4. "FADEC is more complex than traditional FI and mags."
Well, there are different kinds of complexity. It's a trade-off. FADEC systems are much more complex electrically. That is true. But most of that complexity is handled by the engineer who designed it, not by the airframe builder, and not by the pilot. FADEC systems are far less complex mechanically, with very few moving parts, which is a key factor in their potential for better reliability than the traditional systems. FADEC is also far less complex operationally for the pilot, as I discussed above.
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Click to expand...


​
Design complexity is a double edged sword however. For less complexity for the pilot flying, you add a great deal of complexity if/when something goes wrong. Being an Owner/pilot/mechanic, knowing how to work on mechanical FI/carbed and Mag/EI engines, I can just barely scratch the surface of getting my 10 year old CAR running well when something goes wrong. I'm pretty handy with electrical too. I guess my point is, more people can FIX the more mechanically complex pilot managed system than can even begin to understand a computer controlled system.

So I'd have to say that for continued airworthiness, mechanical systems still have the edge. Because eventually everything does fail.
 
FADEC and the A&P

Stephen,

You raised an important issue, but I agree with only part of your conclusion.

You are absolutely correct that FADEC presents a different paradigm to the powerplant mechanic. Today, no doubt there are many A&P's in the field who have never seen a FADEC, and would be rather lost the first time they encountered one. That'll change over time. But you are correct that it does currently present a potential obstacle for the aircraft owner/operator.

About added complexity for the A&P though, I have to disagree. It may appear complex now since it's still unfamiliar, but really FADEC makes life simpler for the A&P as well (although it may have a negative impact on the A&P's income). There's nothing to twiddle with. No set screws, no parts that wear out all the time, no fine adjustments to be made. The system is self-calibrating. Just like modern cars, gone are the days of the "tune-up". The system has a finite number of components (ECU's, sensors, injectors...) and the A&P doesn't go inside them. The A&P doesn't need to understand the internal design of an ECU. When on a rare occasion a component in the system fails, you replace it. It is generally not difficult to isolate the failed component, and in most cases the ECU will actually tell you.

So I guess I'm agreeing and disagreeing. Yes, A&P's will need to update their skills, and that will take time. There may be some hiccups along the way. But it's a step in the right direction.

P.S. Looking at your user name, I presume you use Mac OS X? To draw an analogy, imagine taking a computer technician who has worked on DOS systems for 20 years, and put him in front of a Mac OS X machine for the first time. I'm sure he'll be lost at first. But if he has the willingness to learn, he can become proficient with the new system very quickly, and will probably then recognize how it is vastly superior.;)
 
roee said:
About added complexity for the A&P though, I have to disagree. It may appear complex now since it's still unfamiliar, but really FADEC makes life simpler for the A&P as well (although it may have a negative impact on the A&P's income). There's nothing to twiddle with. No set screws, no parts that wear out all the time, no fine adjustments to be made. The system is self-calibrating. Just like modern cars, gone are the days of the "tune-up". The system has a finite number of components (ECU's, sensors, injectors...) and the A&P doesn't go inside them. The A&P doesn't need to understand the internal design of an ECU. When on a rare occasion a component in the system fails, you replace it. It is generally not difficult to isolate the failed component, and in most cases the ECU will actually tell you.
Click to expand...

Even though it hasn't happened to me, there are definately times where CPU's have given out in automobiles, and left the driver standing still. Even in intersections. :eek: Nothing happens engine wise, until the offending "computer" is replaced. As it is now, I consider our Lyc type aircraft as pure simplicty, when it comes ignition, fuel, and air. And speaking of "pilot load"; there just isn't that much on a several hundred mile cross country. We scan for traffic; make sure the auto-pilots are staying on course and altitude...........and play with the "mixture" to keep awake! :D

L.Adamson --- RV6A
 
Staying awake

L.Adamson said:
Even though it hasn't happened to me, there are definately times where CPU's have given out in automobiles, and left the driver standing still.
Click to expand...

CPU's, like any device, can fail. But their failure rates are far lower than magnetos. Still, unlike cars, aircraft FADEC systems generally have redundant CPU's, so the system can tolerate a single CPU failure. In a well designed system, the likelihood of two CPU's failing simultaneously is astronomically low -- far lower than the likelihood of two magnetos failing simultaneously. Cars don't employ this level of redundancy because a failure of the one-and-only CPU leaving the driver stranded is still only an inconvenience, not a life-threatening emergency.

L.Adamson said:
And speaking of "pilot load"; there just isn't that much on a several hundred mile cross country. We scan for traffic; make sure the auto-pilots are staying on course and altitude...........and play with the "mixture" to keep awake! :D
Click to expand...

The mixture knob demands the most attention during transitions between phases of flight, which is when pilot workload is already at its most critical. Also, even during the cruise phase of an IFR hop, you already have enough to juggle. For those several hundred mile VFR flights in severe clear, I guess I'll have to just enjoy the view out the canopy to keep myself awake. Difficult, I know, but it can be done :D
 
New EFI kit for Lycoming 320/360

rv6ejguy said:
Yes, one of our clients is developing a complete kit for 320/360 Lycomings with flight testing beginning in California near the end of this month hopefully.
Click to expand...

That's good to hear! Can you share any more info? Is your client who's developing it posting any info online? I'm sure many of us would be interested to learn about the details of the system, and its progress through development and testing.
 
FADEC...................would be like putting an automatic transmission on a Harley...:(

L.Adamson ---- RV6A
 
Suggestion

Don't be the first or anywhere near the first for any new FADEC system. Most likely you will be a beta tester and the implications for finding faults may not be pleasant.
 
roee said:
That's good to hear! Can you share any more info? Is your client who's developing it posting any info online? I'm sure many of us would be interested to learn about the details of the system, and its progress through development and testing.
Click to expand...

I've agreed to stay pretty silent on this one until the kit has finished flight testing and is in final configuration to release for sale.

I can say that our client is an RV owner, electronics guy and experienced in these matters. I can also say the kit will use the well proven EM-4 4F ECU, software and hardware (45,000+ flight hours in the last 14 years, hundreds flying plus 12+ million hours in ground applications). The trick is mainly getting all the fuel system hardware, injector mounting, sensor mounting and ECU mapping done properly with good documentation for the DIYer. Those details take time to do right.
 
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