Auto-lean in a Mooney M20

No thanks. Looks like it takes forever to figure out where peak is and then forever to go back to ROP. I can do that much faster. And for the LOP faithful, they'd want the "big pull" to get there. Looks like something fussy that could operate your engine a way you don't want, and you already have something similar in the cockpit. The pilot. :)
 
I tried to watch but the music gave me brain herpes. I turned down the volume but still all I could think about was the music. I think auto lean sounds neat but realistically that red knob needs to be tended to by the pilot.
 
denverpilot said:
It's actually very widely available. Just not in piston airplanes. :)
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Considering the age of the typical piston airplane being flown, is it any surprise? ;)

Back on the topic however, there have been mechanical auto-lean systems around for years. I've never flown an airplane with one of the systems but the reports I've heard have been generally favorable.
 
mondtster said:
Considering the age of the typical piston airplane being flown, is it any surprise? ;)

Back on the topic however, there have been mechanical auto-lean systems around for years. I've never flown an airplane with one of the systems but the reports I've heard have been generally favorable.
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Heh. Autopilots are generally seen as favorable too, but then again, we don't get to ask the dead folks killed by them. They might have said they'd hand fly that day, if they'd have known it was going to misbehave. Ha.

A few Prius drivers got some high speed "fun" early on, too... courtesy of those out of control throttle issues.

Just another system to keep an eyeball on for failure to do what the pilot could be doing. Nice when it's working, not nice when it's not. Mixture isn't that hard to set, so it adds very little value.

But yeah, we're well past where we should be needing to set mixtures at all in the era of cars running tens of years with no ignition maintenance other than changing spark plugs, and no interaction from anyone for fuel-air ratios, and pushbutton keyfob starters.

Think I'd skip the mechanical thingy and hope for something a little smarter built directly into the fuel-air system.

But it does show how heavy and perhaps overbearing regulation will not only stifle innovation but also generate strange side businesses like making what's essentially a panel mounted robot to pull a handle instead of integrating the same tech right into the fuel-air system.
 
Woah woah woah. Linear actuators? Digital feedback control? Definitely not ok. GA was steampunk before it was cool. Make some kind of Antikythera leaning mechanism and then we'll talk.
 
denverpilot said:
Heh. Autopilots are generally seen as favorable too, but then again, we don't get to ask the dead folks killed by them. They might have said they'd hand fly that day, if they'd have known it was going to misbehave. Ha.

A few Prius drivers got some high speed "fun" early on, too... courtesy of those out of control throttle issues.

Just another system to keep an eyeball on for failure to do what the pilot could be doing. Nice when it's working, not nice when it's not. Mixture isn't that hard to set, so it adds very little value.

But yeah, we're well past where we should be needing to set mixtures at all in the era of cars running tens of years with no ignition maintenance other than changing spark plugs, and no interaction from anyone for fuel-air ratios, and pushbutton keyfob starters.

Think I'd skip the mechanical thingy and hope for something a little smarter built directly into the fuel-air system.

But it does show how heavy and perhaps overbearing regulation will not only stifle innovation but also generate strange side businesses like making what's essentially a panel mounted robot to pull a handle instead of integrating the same tech right into the fuel-air system.
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Not sure exactly what your point is, but my point is that much like electronic ignition, you're not going to see it in the majority of the airplanes being flown because the airplanes being flown were built 50 years ago when things like what is being discussed didn't exist. So your only way to install this technology in the majority of the fleet is through the STC process. But nobody is going to pay for the STC to install this, because it costs too much (cue the guys saying "for that price I'll just lean it myself!"). So unless things change drastically, we're going to be leaning engines manually for a while yet.

I agree that it is a bit dumb that new aircraft engines and aircraft designs don't have modern technology in this area. I personally think Cirrus should have pursued an aircraft engine implementation that is started and stopped with a key or push button, just like a modern car. If they did that I'd bet they would earn even more sales than they already have.

Regarding the old mechanical leaning systems, some of them you didn't have a choice in the matter. I can think of at least one airplane that came with no mixture levers, it was all done automatically. As you can probably guess, how well the system works is likely going to be directly tied to how complex the system is and how well the mechanic who maintains the system knows the system.
 
Sorry to raise an old post, but I came across this and wanted to respond and provide some information about Auto-Lean. Auto-Lean is a computer that reads EGT and controls a linear actuator that is attached to the mixture control via a quick disconnect. The software adjusts the speed to approximate the response time of the EGT probe. The EGT probe response time is typically the limiting factor in a human accurately determining peak. Approach too fast and you can be many degrees off of an accurate peak reading. While I pulled the original video some time ago (sorry about the music) I can assure you that the system accurately determines peak and target. The system is independent of the EGT display. In constantly improving the product, the latest software finds peak and target significantly faster than the original seen in the video. We can also do custom software if required. I have been using the system exclusively since developing the system about 5 years ago. While I agree that you don't need it, the same can be said about many of the things we have in our airplanes and cars. What Auto-Lean offers Is the ability to achieve repeatable results without distractions or interruptions that often occur when leaning correctly. It allows you to look out, instead of staring at the EGT. It also offers the ability to lean as you climb and enrich as you descend. If you never forget this stuff and never get distracted, than it may not help you. The system has an AML-STC for a multitude of aircraft and we have PMA. The system went through FAA flight testing and has multiple safeguards in the event of an unexpected failure. These include multiple software safeguards, electronic and mechanical over-rides, a lean runaway prevention and warning circuit and a quick disconnect to revert to the basic configuration. Auto-Lean was developed as a compromise for those who have a favorite EGT setting for a specific mission, but don't enjoy the "getting there". You pick the setting, Auto-Lean takes you there. Our web site has lots of new information, please take a look and feel free to contact me if you have questions. (Because I am new here I can not post a link).
Regards,
Rob Takacs
Flight Enhancements
 
Welcome to PoA, hope you stick around.
 
Rob, why would you not use an O2 sensor in the exhaust stream instead of EGT? It's been automotive technology since the mid 1980's for air-fuel mixture control. We use it in racing applications too. Even though we watch EGTs, we don't use them in any kind of control loop. There has to be a good reason this tech has not been applied to piston airplanes, and that's why I'm asking.

I think any type of manual human intervention leaning after the 1980's is kind of silly.
 
The Gopher engine I had on the Navion had an altitude compensator on the carb. You didn't touch the knob below 12000.
 
455 Bravo Uniform said:
Rob, why would you not use an O2 sensor in the exhaust stream instead of EGT? It's been automotive technology since the mid 1980's for air-fuel mixture control. We use it in racing applications too. Even though we watch EGTs, we don't use them in any kind of control loop. There has to be a good reason this tech has not been applied to piston airplanes, and that's why I'm asking.

I think any type of manual human intervention leaning after the 1980's is kind of silly.
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HI
I actually have it on paper and it would not be a difficult change to the Auto-Lean. It would respond faster. The problem is the lead. In talking to folks who use it or have used in on avgas fueled aircraft, they start becoming inaccurate after anywhere from 50 to 150 hours and must be replaced. I suspect it depends on how rich or lean you run. At the lower end of that range, I don't think people would tolerate it. If there was a demand, I would certainly follow up on it. In the version I have on paper, I would use a commercial O2 sensor with its own display and tie it to one of the Auto-Lean spare inputs....and then start the certification effort. With EGT, the absolute temperature is not as critical as the relative temperature. With O2, the value is more critical to establishing the stoichiometric ratio, thus a drift has a more significant effect that would need to be delt with through occasional calibration....or at least that is my take on it.
 
Yes, indeed, welcome.

My experience is with the EFI turbo V6 Buicks, but I am no expert. There are multiple feedback loops, including air temp, mass air flow, throttle position, etc. and spark advance control as well. I've toyed with aftermarket units from FelPro/F.A.S.T.

I'm just surprised new certified aircraft don't have fuel mixture electronically controlled; I assume there is a good reason, but wish I knew what that reason was. If a Cirrus can be operated without a prop lever, it should be able to fly without a mixture lever, technologically speaking.

Lead fouling is a concern, true. Might that be the sole reason? Heck, for the cost of an O2 sensor, you could replace at each oil change, or sooner.
 
455 Bravo Uniform said:
Yes, indeed, welcome.

My experience is with the EFI turbo V6 Buicks, but I am no expert. There are multiple feedback loops, including air temp, mass air flow, throttle position, etc. and spark advance control as well. I've toyed with aftermarket units from FelPro/F.A.S.T.

I'm just surprised new certified aircraft don't have fuel mixture electronically controlled; I assume there is a good reason, but wish I knew what that reason was. If a Cirrus can be operated without a prop lever, it should be able to fly without a mixture lever, technologically speaking.

Lead fouling is a concern, true. Might that be the sole reason? Heck, for the cost of an O2 sensor, you could replace at each oil change, or sooner.
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Well for one the process to certify any component in a certified aircraft is expensive and time consuming... for another there are a lot of people in the aviation community who still believe that a carburetor is more reliable because it has less parts and doesn't require sensors/power.

I am not one of those people, I'd love EFI but for some folks this 80's technology is still too cutting edge and unproven. Welcome to the world of certified aircraft I guess.
 
cowman said:
Well for one the process to certify any component in a certified aircraft is expensive and time consuming...
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Ditto... thus the reason most FADEC systems are on experimental and home-built aircraft. The Lancair Evo is a good example. ;)
 
455 Bravo Uniform said:
Yes, indeed, welcome.

My experience is with the EFI turbo V6 Buicks, but I am no expert. There are multiple feedback loops, including air temp, mass air flow, throttle position, etc. and spark advance control as well. I've toyed with aftermarket units from FelPro/F.A.S.T.

I'm just surprised new certified aircraft don't have fuel mixture electronically controlled; I assume there is a good reason, but wish I knew what that reason was. If a Cirrus can be operated without a prop lever, it should be able to fly without a mixture lever, technologically speaking.

Lead fouling is a concern, true. Might that be the sole reason? Heck, for the cost of an O2 sensor, you could replace at each oil change, or sooner.
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Replacement at oil change is a thought. Will have to consider that. Ultimately the question is, would people buy it? There are some experimental folks flying with O2 displays and there was even an STC for one a few years ago, but I guess it is no longer available. lead fouling did limit sensor life, but I'd don't know if that is why it is no longer around....I suspect it was the market...

There have been a couple of big attempts at marketing FADEC for GA. There have been at least a couple of certified systems, but they just didn't sell well. I'm sure cost was a driver, thus my attempt to target a much lower price point. Certification costs are considerable so that is a driver, but not the only driver. In the old supply and demand area, the demand does not seem to be out there. Like you, I don't fully understand why. In the case of the Cirrus, the Auto-Lean is not too far off, technically, from being able to remove the mixture control. It would take a higher software integrity level and a back-up system. In the case of today's Auto-Lean, we take credit for the mixture control essentially being the back-up. The only time I touch it is at start-up and shut down.
 
azblackbird said:
Ditto... thus the reason most FADEC systems are on experimental and home-built aircraft. The Lancair Evo is a good example. ;)
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The vast majority of modern commercial jets, business jets and turboprops are FADEC.
 
azblackbird said:
Yep... and eventually the systems will be offered in a few select models of new GA aircraft. :yesnod:
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Eventually?

Business jets and turboprops are considered GA.

But if you mean smaller aircraft with piston engines, I thought the Diamond DA-42 and DA-62 already had FADEC. I believe there might be others as well.
 
DutchRoller said:
But if you mean smaller aircraft with piston engines, I thought the Diamond DA-42 and DA-62 already had FADEC. I believe there might be others as well.
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Aren't most/all Diamonds diesels? I don't know, I don't keep up on that company. :dunno:

I thought Mooney at one time offered a FADEC package. I don't recall any other GA small plane manufacturers currently offering FADEC systems. Could be wrong, but I haven't heard of any. :dunno:
 
I think only the Diamond diesels have FADEC. Regarding Mooney, I think only the Porche Mooney had FADEC. As I recall, all have been converted to a traditional Lycoming or Continenetal. Can't think of any others at this time.
The ones I am familiar with were STC kits and I don't think they ever made it to OEM aircraft.

I think part of the downside of a full FADEC is the need for an electronic back-up, often in the form of a second alternator. Maintaining the manual controls as a back-up saves weight in that case.
 
Most Rotax engines don't even have a knob. It's all done automagically for you, and seems to work fine.
 
takair said:
I think part of the downside of a full FADEC is the need for an electronic back-up, often in the form of a second alternator. Maintaining the manual controls as a back-up saves weight in that case.
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Yep, dual alts, dual ECUs, dual batteries, etc. There are a few GA SE-P aircraft in the pipe right now that will soon be using these "flex-fuel" engines...

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