Single Lever Power

mmarien

Murray M.
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With the ADAHRS+EMS data now available from the Skyview has anyone investigated managing constant speed propellers for a single lever solution. I understand that Cirrus has a single lever for prop and throttle but just use a mechanical scheme. RPM is 2700 for low and high lever positions and 2500 for cruise positions. Works I guess but doesn't use feedback available from all that avionics equipment.

I'm thinking the propeller RPM could be managed similar to electronic ignition and electronic fuel injection using tables or closed loop feedback (pitch + power (MAP/RPM) + airspeed).

Any thoughts?
 

DBRV10

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I am going to sound a bit harsh here......but for goodness sake, operating a piston engine with a throttle/RPM/Mixture is not hard.

Problem is in flight training none of us....read that again, NONE of us are taught anything about piston engines and their operation and management nor how to use an EMS. Fact is 98-99% of the Dynon EMS customers do not understand what the EMS is telling them in ALL parameters. Sure they understand some of it, but as for engine diagnostics on the run, it is a dismal fail. You should see the level of knowledge coming out of flying schools producing CPL's.

Even those who think they know, do not know what they don't know. heck, myself included....I never stop learning.

So you make it even dumber like Cirrus have and all you get is dumber pilots, and that is fine so long as you never have any problems. In your dreams maybe, but not in a plane.

So the solution is education. Not single lever ops. Even a turbine which effectively has single lever ops, has a lot of other EMS stuff, and it pays to know about that too.

OK rant over..... for now ;)
 

Roger_Peterson

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David, there might be more than 1 or 2 % of us out there that understand engines and their instrumentation. Not rocket science for someone that grew up building engines..
 

mmarien

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I think you are missing the point here. I agree that learning to use conventional throttle/prop/mixture levers is not difficult. Developing a better method obviously seems incomprehensible to some people.

I think we've come a long way from the days of having to back your Model T up the hill. Isn't that the same era that throttle/prop/mixture levers were developed. :-?
 

DBRV10

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David, there might be more than 1 or 2 % of us out there that understand engines and their instrumentation. Not rocket science for someone that grew up building engines..

Roger, maybe there is, but not very much more, you might be one of those in the 1-2% but even those engine builders out there amaze me at some really dumb OWT's that they believe...and think are facts.

The problem is they think they know these things because they were handed down the OWT's from respected mentors....and on the mythical facts grow.

So while I probe around the majority of pilots I meet looking for evidence of data backed fact knowledge and understanding, and some engineers too, I am constantly amazed at the lack of understanding, and the lack of desire to go learn, even when the OWT's are debunked.

It is perplexing in the least.

I think you are missing the point here. I agree that learning to use conventional throttle/prop/mixture levers is not difficult. Developing a better method obviously seems incomprehensible to some people.

I am missing your point about the Model T, it is not relevant. The Fadec systems we have on the Cirrus and some TCM engines and others work, and with the Cirrus system you chose ROP or LOP, but the problem here is you still need knowledge.

The TCM FADEC works, and they have had no end of trouble getting it to work and now will not support any Experimental customers, so that tells you something.

The problem is even with a FADEC that works fine, if you do not have knowledge, and you do not have the ability to manipulate, how can you diagnose and save you butt or wallet one day? There is a big drawback to going this way.

By the way, I have seen the TCM FADEC not cope with simple things like a MP sensor issue, on my engine, well it makes the Dynon display a funny number, not cease delivering power  :eek:

Turbines.....different story, less complex on so many levels, far more development has been done.
 

mmarien

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What is this David? Some sort of cyber bulling? Should I be scared off the forum or something? Now I'm missing the point. I be happy to read your thoughts on the discussion but so far it's lacking anything meaningful that I can benefit from. Time to disgorge all that knowledge and understanding that you claim you have and enlighten us. We wait with bated breath.
 

DBRV10

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What is this David? Some sort of cyber bulling? Should I be scared off the forum or something?

No and No. This is challenging the proposed concept. Simple as that.

but so far it's lacking anything meaningful that I can benefit from.
Well I can't help you then. You would need to do a bunch of research on the topic yourself and form some opinions based on scientific data. If this concept was easy, everyone would be doing it now. Look at all the Electronic Ignition systems that are available for experimental aircraft. I would not install any of them. Not saying they do not fire the spark plugs, and I fly a mates plane with one, but they only half address the situation. I could sit here for hours on this alone. But I do have plenty of other more pressing things to do.

So if a single lever system was easy....why are there none? That was basically your original question. You asked for thoughts, I gave you mine. I think it is a dumb idea, taking out the human brain from the loop. And then giving it no way of making parameter adjustments should you have detected a problem.

Even GAMI have a really good system for ignition control, yet it has been years and still not on the market. How many of us have pressure sensors in our engines? The sort that sample at a rate of something like 1 MHZ recording ICP's? None of us. So how does Dynon or someone else come up with a system to retrofit to all sorts of engines without resorting to this? Lookup tables are fine, we use them here at work, but when it comes to an aero engine, that is fine provided you have the table right. But when things go astray, like a failing plug or injector clogging or worse.....what is it going to do. How will it handle it.

Let me ask you to ponder a quick question, and you have to be honest with yourself here....and you have only 60 seconds to answer this............... You are flying over the Rockies at 14,000 feet, fat dumb and happy at night, LOP or ROP, and your wife is admiring the moon in the night sky, kids asleep in the back, and you notice your EGT on cylinder 4 has dropped a bit, and the CHT on that same pot is rising fairly quickly. You have no airports anywhere in gliding distance, the Lowest Safe is not far below and an outlanding there is certain death. You now have 30-40 seconds left to make a correct decission. So what did you do?

Would I trust this to some Lookup Table and fault diagnosis box on a single lever operation............ NO WAY!!!

Time to disgorge all that knowledge and understanding that you claim you have and enlighten us. We wait with bated breath.

I find that comment rather condescending, and rude. It may well be you meant it with some tongue in cheek humour and given the seriusness of this topic, or my serious take on it, I am not easily seeing any humour in the question. So my apologies if you had meant it more humourously.

I could sit here for days and days, and not be able to disgorge the info you need, or want, for a start I have no idea what it is you know, or dont know, and what you understand and do not. This is not just a few paragraphs and its all over thing.

And this is the problem, when we are taught to fly, most of what are taught about engine management is either wrong or misguided and is able to fit into less words than this post. So trust me when I say, when I was taught to fly, just like everyone else I come across, we all learned the same stuff. It is just not enough. What I did was make it a never ending quest to learn more but for a while, I did not know what I did not know. Then I started learning more about aero engines from guys like George Braly John Deakin and Walter Atkinson, then as my education expanded my knowledge, I started to realise, I know stuff, but did not understand the stuff, then the more I understood, the more I needed to know.

This takes a lot of time, it takes a lot of effort and money. I did have the benefit of being an engineer, and having been in motorsport, racing cars building engines etc, so this all helped, but the time you think you know it all, you are wrong, so I have just made it my job to learn, soak it up like a sponge.

Maybe I am suffering the internet written words do not offer inflection and tone syndrome, maybe you are too, but if you want me to disgorge education, that I have worked hard for and spent a lot of money on, you may need to lighten up a little  ;) and ask some good questions, engage in debate based on data proven facts, not old wives tales passed down from instructors or mechanics.

I have a family motto or two.....one that springs to mind, "Don't wish it was easier, wish you were better" and that sums up my thoughts on the dumbing down of aviation and in this case a simple one solution single lever to fit all.

All the best!  ;)

David
 

DBRV10

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Jake, with utmost respect, this is under the GA discussion forum.

The question was posed and asked for "Any Thoughts", I gave some thoughts, and then got accused of cyber bullying. So yeah maybe I should shut up, say nothing and nobody learns anything or benefits from a robust discussion.

I am happy for robust discussion but I will not cop alleged cyber abuse, and baited with comments like the last line.

I am happy to debate and share knowledge, but not happy with condescending remarks. I do however hope that the posted above comes back with serious concerns and questions about why he thinks I am so far out of it, and why companies like TCM Lycoming and GAMI have not flooded the market yet with automated systems. In fact if anyone can GAMI could, they are streets in front of everyone in engine testing, but no silver bullets yet. PRISM is the closest thing to a major leap forward in 60 years, and still not on the market.

So healthy debate lets begin, or I will lose interest very fast.

I will concede that I expanded the single lever concept to include mixture control, the RPM control could be done electronically, it is on the various CSU's for subbies etc, but in a Hartzell hydraulic setup all you would do is control a servo controlling pitch, I see no advancement is using electronics here, especially when redundency is involved. No gain, lotsa pain. Single lever ops....includes all parameters.
 

mmarien

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Well I can't help you then. You would need to do a bunch of research on the topic yourself and form some opinions based on scientific data.
Thanks for your thoughts David. I thought I'd start on this forum, but the topic seems to be hijacked by naysayers.
 

DBRV10

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Not much of a debate if you call it hijacking???? What the?

I give you a bunch of reasons why I think it is not a good concept, and you have not countered anything with good engineering reasoning....you call that hijacking?

Lets see some good argument for it then. I want to see it, if it can work, but it needs to work, fully, unlike many EI's.
 

Haukinger

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I like the idea. Do you know of the V-Prop?
If the prop can control the pitch by itself, the efis should also be able to do it.

What about taking it even one step further? The auto pilot could take control of the one lever when engaged...
 

mmarien

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I had a look at the V-Prop. Interesting idea. It looks like it is based on airspeed and engine RPM. The engine RPM is interpreted as power and the airspeed is derived from the free spinning vane in front. High power/low airspeed ratio (climb) or low power/high airspeed ratio (decent) causes the pitch to change finer. At cruise the pitch will coarsen up. This is the same concept as the mechanical Cirrus scheme although the Cirrus method has no feedback other than the throttle lever whereas the V-Prop uses two inputs. Both mimic the normal adjustment of throttle/prop through pitch changes.

The RPM/power input needs a little work. It looks like V-Prop requires the throttle fully closed to affect the prop pitch on decent. Throttle fully closed on decent has the side affect of shock cooling the engine. This is where %power derived from the EMS and pitch from the EFIS would be a benefit. On cruise the automatic transmission in my car shifts down to control the speed going down steep grades. In an airplane it's nice to make up the time used in the climb on the way down, but pulling back a bit on the throttle while pitched down should cause the prop to change pitch to control the airspeed in decent. It looks like the V-Prop doesn't recognize such a subtle change.

It's difficult to get my head around the concept of fixed power lever position as opposed to controlling the RPM (airplane) and speed (automobile). I think with a the single lever power solution both the RPM and airspeed will vary depending on the attitude of the plane even though the throttle isn't moved. For instance, %power can be increased by increasing the RPM without moving the throttle. On cruise climb, the power could be increased by increasing the RPM without moving the power lever. Much like an automatic transmission shifting down to try and maintain speed on a climb.

Thanks for pointing out the V-Prop. Lots of good ideas there.
 

DBRV10

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Just thought you guys might enjoy this video, apply the Automation Dependency to this thread and my argument against the idea of a single lever system for the piston aero engine.

http://www.youtube.com/watch?v=h3kREPMzMLk&noredirect=1

If nothing else it is a good educational piece of video from AA. It does take about 25 minutes so after watching come back to the info below.

For instance, %power can be increased by increasing the RPM without moving the throttle.

OK, now we are able to discuss concepts and things. Let me explain a few things with a piston aero engine that might impact on your thoughts.

A quick question to ponder first. Which is the "True and most effective" Power lever in a piston aero engine setup with all three levers? Throttle, RPM or Mixture?

The correct answer is mixture, and if you need me to explain that I will, but lets move on for the moment.

1. Wide Open Throttle is the most effective and efficient position to use. You would not fly around with a dirt clogged air filter, so why would you do the same thing by pulling throttle off except for taxi and slowing down in the circuit area, where the efficiency is not important, landing speeds are.

2. During take off and climb, generally on the Rich Side of Peak, although you can do LOP climbs if you wish, you will normally be climbing at WOT/Full RPM and Rich but leaning in the climb. In this case, HP produced is a function of Mass Airflow, and that is MP & RPM, reduce either and power drops.

3. During a cruise setting, best done WOT and LOP, power roduced is directly related to Fuel Flow. Sure some extra losses at higher RPM compared to slower RPM, but at whatever RPM you choose, %HP is determined by fuel flow. Increasing the RPM does nothing of note and in fact due losses the delivered power is less. This also applies to a LOP climb.

Cheers :)
 

mmarien

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Thanks David. While those of us not in the 1-2% struggle with those concepts, they are entertaining. Who is that guy in the video. I got an ID ten T error so I wasn't able to watch the whole thing. It was just a lot of dots and dashes. What I did see inspired me to take control and I started hand coding my TCP/IP packets with a straight key so if this message seems short, just consider the effort used to deliver it. ... .... .. - oops, sorry wrong channel. The benefit is that you can't make a mistake with hands on.

Just out of curiosity what is your favorite method of Internet communications. Is it automated or strictly hand coded? You just can't trust an automated computer thingy while a mechanical lever for hand coding is available eh? ;)
 

DBRV10

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My replies are brought to you by morse code..... ;) ;)

The guy in the video is from AA, training captain. Don't know him from a bar of soap, but a good lecture all the same.
 

mmarien

Murray M.
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FIO The Sept.2010 Kitplanes magazine has an article on the Lancair Evolution piston version. "Flight Review: Lancair Launches the Piston Evolution" They are trying to develop the Lycoming TEO 540 iE2 as single lever. If you have the article check out the CHT that Lycoming claims are within range for the engine. They are using knock sensing for detonation prevention.
 

DBRV10

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They are using knock sensing for detonation prevention.

Indeed they are. I saw this engine a couple of years ago. And it is a step in the right direction by including knock sensors. TCM tried to do it without.

If you ever see the GAMI Prism system and the Dyno stand which is running a Chieftan engine, they intruduce detonation quite severely, which is not hard to do on a Chieftan engine, and then they switch on the PRISM, detonation vannishes. This is ignition control only, not full engine control.

This is not exactly new.

The concept of single lever does start taking the pilot out of the control loop. So when something goes wrong like a ceramic breaking in a plug, I wonder how it deals with that? This is what concerns me the most. Operating a piston aero engine is not hard, but it takes some education to do it really efficiently and effectively.

As for a EFIS manufacturer setting out to develop a single lever controller........ I dont think so.

As for the CHT range, I have not seen the article, maybe you could post some of it up here. What was the range? What does it actually operate at?
 
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