John,
Mac McClendon (SP), the longtime magazine editor, wrote that. I will read that when I get a chance. I will also stop at the Lycoming both at OSH (again).
Believe me, I am not against full FADEC. Only a poor implementation of it.
For now manual gives me choices automation doesn’t. Automating a bad model isn’t an improvement. It is only automation.
I want to see what’s under the covers before I declare success and marry it.
“The iE2 runs lean of peak. Lycoming has conquered the engineering challenge, which seems to have been the easy part”
If so that would be a huge concession on the part of Lycoming. They have uttered such nonsense as don’t do it because it is an “oxidizing flame” for years. The truth is there never was an engineering problem. They made up a lot of whitewash and BS. Perhaps now they are comfortable with the fuel delivery system.
If it runs LOP, do you know if will it run high power LOP?
Lycoming states it runs either lean of peak or rich of peak depending on many variables including the amount of power demanded from the engine, so I’m not sure. Continental would have a different map because they are basing it on a different engine and that would presumably run LOP more often. Whether that produces a better result or not I don’t know, but the result is all I’d be interested in. Cirrus switched to a Lycoming for their SR20 G6 and it won’t run LOP, replacing an engine that will run LOP. They both perform about the same, with promised lower maint costs on the Lycoming.
As a pilot I don’t really care about LOP or ROP as long as the engine is operating optimally. I believe those are all better with a FADEC, and not by a marginal amount. There are so few out there it’s hard to prove. It seems the number of people willing to give the engine a serious look is unfortunately small, and I don’t think that has much at all to do with the engine.
“As a pilot I don’t really care about LOP or ROP as long as the engine is operating optimally. I believe those are all better with a FADEC, and not by a marginal amount. There are so few out there it’s hard to prove. It seems the number of people willing to give the engine a serious look is unfortunately small, and I don’t think that has much at all to do with the engine.”
John,
You are Illustrating the difference between pilots and owner operators. Pilots for the most part don’t give a damn how they operate it as long as It gets there fast. Owner operators who care about operational costs and not replacing engine parts prematurely want the flexibility of operational range. The Lycoming switchover decision in my honest opinion was because the training operators were used to the Lycoming simplicity and were not mentally equipped to work on the Continental. That is unfortunate because the continental 360 is the smoothest operating six cylinder on the planet. But for fleet operators if that’s what they want then that’s what they get.
I don’t believe there is a practical loss in operational range. A fadec engine should more reliably make it to TBO when run at similar power settings.
If there is a real loss in operational range, maybe there could be a map that could be loaded by an A&P (conservative map, aggressive, etc.). Some aftermarket car mods do this.
"I don’t believe there is a practical loss in operational range. A fadec engine should more reliably make it to TBO when run at similar power settings.
If there is a real loss in operational range, maybe there could be a map that could be loaded by an A&P (conservative map, aggressive, etc.). Some aftermarket car mods do this"
John,
No disrespect intended but you are virtually the opposite of what you accuse the non believers of. While I want data and tend to not believe, you want to believe with limited data and field experience. Time will tell which is right. I do think this will win over time because pilots want it and don’t want to learn to run their engines.
I also know the manufacturers will use this opportunity to force me to run my engine their way. No high power LOP for example.
As far as your mechanic making a map change, that absolutely will not happen with a certified engine. Well, unless Lycoming authorizes maps. I can tell you as a mechanic, I cannot do that on a certified engine without approval. Yes, anyone could in an experimental. Different rules.
As far as making TBO, engines have been doing this for decades. And beyond. Mine is just about there and running well. The number one reason for not making TBO is lack of use. This cannot fix that.
I do agree that often times forum chatter is passionate garbage, hoping this thread doesn’t head that way.
You are describing how the FADEC controls the engine, that is the good stuff that we are missing now. The question is how does the pilot control the FADEC? For different settings of the power level, how is the engine operated? Lycoming marketing only states that for each power setting the FADEC will be mapped for the most efficient operation of the engine. Who knows, maybe they switch over to LOP quickly, but I doubt it. A simple chart of engine power versus fuel flow would suffice, perhaps you have seen one that you could share?
In my early years , I used to use a Power Commander III to create and tweak maps for power setting, riding style in my motorbike. I will be surprised if FADEC capable aviation engines won’t have such kind of adjustments for different flying styles( power, detonation margins, fuel type, LOP/ROP, fuel/air mixture ratio …). It will be a different discussion as how and who are eligible to perform these actions on the engines and also, if the ECU given a lower/upper bounds can dynamically and safely change the parameters within the bounds during active flight.
That would be really cool if we could alter the mapped settings within certain parameters, but I am skeptical that we will get the leeway.
I’m not a believer or a non-believer. I just haven’t seen anyone argue against piston FADEC that knows much about it.
I don’t, and that would be interesting. It would be in a POH but as far as I know it’s not in any civilian certified applications so it may not exist in official form.
The Evo lists 23gph at max cruise FL240, 18gph at economy cruise FL250. That’s too general to make a comparison though. A fair comparison would be two engines in the same airframe, which I don’t think exists.
A search on the lancair forums turned up only two results, one was someone frustrated at the lack of detailed information, an the other was an interesting post describing why we can’t use oxygen sensors like cars do (lead).
Lots of questions to ask in the booth at OSH!
From the article “Lycoming IE2: Incremental Technology” printed in the August 2010 issue of Aviation Consumer:
"When we probed about the IE2 operating strategy, we learned that Lycoming wants to change the conversation about lean-of-peak versus rich-of-peak operation, preferring instead to say that the IE2 runs at the best efficiency for whatever power level the pilot has commanded. In a nutshell, that means it fuels heavily for takeoff and climb, backs that off in high-power cruise and runs lean of peak when it senses the pilot has pulled the throttle back to improve economy.
We didn’t get a detailed look at the fueling map, but engineer Jim Morris explained that the fueling schedule—as least the version developed thus far—is designed to compromise between the best efficiency and acceptable temperatures. At high-power cruise, it appears to be running rich of peak, based on the fuel flows we were quoted. But when the pilot pulls the throttle back, the ECU smoothly adjusts RPM and fuel accordingly until, at some point, it fuels around the peak CHT spike just rich of peak and transitions to lean of peak operation. The prop RPM change is a smooth enough ramp not to be noticed by the pilot, although the fueling happens almost instantaneously. But unlike the Cirrus approach of running Continental engines lean of peak at high power, the IE2 goes lean only at lower power settings, probably around 65 percent or lower."
In terms of temperature limits:
“CHT is also an automatic operational limitation. The upper end limit is 450 degrees F, but normal operation is allowed up to 420 degrees F. When the limit is reached, the ECU adjusts first with fueling—richer or leaner, presumably based on throttle position—followed by slightly retarded timing.”
I was very skeptical that these engines had knock sensors as historically it has been hard to get reliable knock sensing to work on nosy aircraft engines. However, it appears that his is a first for GA piston aircraft engines:
*“Acoustic knock detection has been a difficult nut to crack for air-cooled aircraft engines because their inherent vibration signatures make pinging difficult to extract from the hash of background noise. But knock sensors have gotten better and there’s more processing horsepower available to separate the wheat of pinging from the chaff of banging valve trains and the whirr of gears. In any case, with individual cylinder knock detection, the IE2 suppresses detonation the same way it handles high CHTs—first with fueling, then with timing adjustments.” *
The article contains additional information on the sensors and how the system is connected together. Subscribers to Aviation Consumer have online access to all past articles.
Enjoy!
Dale
(I want to reply to a thread, not a person… so ignore the “replying to…” part of this header)
I haven’t seen anyone bring up weight yet. I would LOVE to have an aircraft engine as “advanced” as the one in either of my day to day drivers. Common rail injection, individual throttle bodies, direct ignition, the list goes on…
What has been brought up is the sensors and electronics to do this. I think this is a no-brainer as the automotive industry has been doing this long enough, it shouldn’t be difficult to bring some of this tech over. But all of this tech adds weight, which all of us are acutely aware of (maybe better said "none of us want?). The current FADEC diesel engines are much heavier per HP than their current 100LL brethren. I’m sure a 100LL (or even some UL design) could be made that was in the middle between making good power AND being FADEC heavy (ie. Diesel/JET-A burning), but…
No manufacturer wants to do it because (as was pointed out) it’s expensive for what seems like no real return (no one wants it problem), which I think is a Chicken/Egg issue. I think if a manufacturer came out with a good/reliable FADEC piston engine that didn’t weight 100+lb more and made as much (or more?) power, people would clammer all over it. Until someone put it in their airplane, and something went wrong, and they got sued back into the old ways of doing things because innovating and getting sued is expensive.
Maybe I’m wrong… I know I asked extensively about a diesel/JET-A option and/or at least some level of FADEC before I signed any purchase orders.
I just want to get in my plane, push the start button, have 1 knob/handle to mess with (throttle), and be able to trust that it’s all working correctly and isn’t going to fail in some way that I wouldn’t have also caused it to fail if I was doing it by hand. But then, I’m a child of the computer age. I trusts computers, but not software developers 
Most of the current diesels are based on a Mercedes Benz car engine with a gearbox on them. Clean sheet designs should weigh about the same as a 100ll turbo with the same power. Keep in mind for the same range you’re carrying less fuel weight.
The Diamonds work this way. Watching a pilot press a button and the engine whirrs to life makes me think of course all av engines should work this way, then I go back to real life and review my warm start procedures, cold weather procedures, and hand-eye coordination.
Conversely in the 15 years here on copa, I haven’t seen anyone that advocates FADEC that knows much about running their engine at high power LOP.
Every 6 months or so, we get this discussion about our WW2 engines. Usually it is a newbie that is having trouble hot starting their engine or hating learning the mixture control.
Until a pilot has had experience with bad EGT and CHT sensors, spark plug failures, a partially blocked injector or a mag failure, then they will understand how hard it is to do a FADEC engine (on a cheap plane like the SR22). A trained pilot can handle these failures and get the plane back on the ground - without damage.
Unfortunately a computer system relies on sensor information. It uses an algorithm that depends on working spark plugs (all 12), working injectors, working exhaust valves, working oil temperature, pressure, rpm, manifold pressure, fuel flow sensors. With all that correct, the computer can run the engine perfectly.
But when one or more of those are wrong, the computer could actually do the wrong thing. It is not a matter of enough software. When these engine issues occur, the pilot can troubleshoot by using different settings of the the throttle, the mixture, the mag switch and the boost pump. It is not always obvious what is wrong - and how to deal with it.
If you fly long enough, you will encounter most all these issues individually. You will then grasp how serious it is to understand how the engine operates. It is simply too important to leave it to a computer (and some sorry, half baked software).
I saw the FADEC engine in the SR22 at TCM (Mobile, Al). There was a lot of wire everywhere - you could barely see the engine. We actually laughed when we saw it. Many of us had experienced several sensor failures so we asked what would happen if that occurred. Well it would revert to Rich of Peak was the answer. What about a clogged injector? Same answer… Wouldn’t that would burn up the cylinder? Silence…
Yes it worked. We watched an engine start with a push button. Shift to Lean of Peak (Less than 65%). Then shift to Rich of Peak. There were only 2 cruise settings. They also showed a hot start. It would cost $10k. I would not take it if they paid me $50k. Seriously.
By running high power LOP, my plane flies faster and uses less fuel. It saves so much on operating costs, it will pay for an engine overhaul. The FADEC engine could not do this. If anything, it could cause a premature engine failure.
Yet all it takes to run our engines correctly is knowledge and some experience. You can pay less than $1000 and to get smarter. There is no extra weight or extra cost to this knowledge. And it can save you when things go wrong.
[edit: fixed FADEC spelling]
What does the “I” stand for?
Dale,
There is interesting information in there. The CHT limits are frightening. LOP appears supported, but only as Best Economy (
Things to like. Things to not like.
“I’m not a believer or a non-believer. I just haven’t seen anyone argue against piston FADEC that knows much about it”
Just for clarity, how many of those you spoke with fly a piston FADEC engine?
I like the idea of FADEC. Already in Dales post he confirmed some of what I was concerned about.
Apparently E… [:D]
Thanks. I’ve edited the spelling on that post.
The gist of my comment to be clear was in speaking (or reading online) with people who do not own piston FADECs, don’t know much about them, but know they don’t ever want one. The only folks I know of that fly piston FADECs are Diamond drivers and they love them, but those are geared liquid-cooled diesels. I don’t know how many iE2s are flying in the civilian world but I think they only built 2 piston Evolutions before that company went under, so could it be only those 2? I’ve never spoken with an owner of one of those but would love to hear their thoughts. Incidentally I did most of my multi training in a Lycoming DA42 mostly because I was told the FADEC version is too easy (auto feather, push button restart, etc.).
I plan to take a closer look at the Mako in OSH and ask about an iE2. Not sure I’d want to jump at the chance to be the very first one to build one with a new engine though, FADEC or not.