Future of Mooney: Speculation thread

[MooneyMitch]

3 minutes ago, Blue on Top said:

To follow on to Mitch’s comment, the aerodynamics that were done to make the “J” can be done much, much better today.  Yes, all the Mooneys can be made faster and more efficient with today’s knowledge/CFD.

I look up to and highly respect Al and Art Mooney, Ralph Harmon (the real designer of the unbreakable, metalized Mooney wing) and Roy LoPresti, but we know a lot more now.  And yes, despite all the generally negative comments about the younger generations, have brilliant minds today, too.

PS. Mitch: The “Ovation” would be a great one to start with ... both faster and lighter (=> more useful load).

Out there, from time to time, I’ve heard that the current M20 airframe configurations are maxed out for speed modifications.   Hmmm, I say.

Yes, young brilliant minds (and supporting technology) are amongst us...... I saw a bunch of them at my recent SpaceX tour.

As we all ponder and comment on this factory shut down, I have to wonder if the thought of lightening and aerodynamically adjusting the M20 airframe was ever discussed by Mooney suits and engineers, and janitors! 

[Blue on Top]

3 hours ago, carusoam said:

Welcome aboard Blue.

Where have you been?

What kept you from joining us earlier?

I hope you can stay around...

-a-

 

Thank you!

I have been very busy, but need to have better time management to get all the information … like that is possible

I did join earlier, but only posted a couple things … probably on the use of AOA.  I'm developing a product now.

I'd like to stay around a long time

Thank you!  -Ron

[Blue on Top]

3 hours ago, MooneyMitch said:

I have to wonder if the thought of lightening and aerodynamically adjusting the M20 airframe was ever discussed by Mooney suits and engineers, and janitors! 

Suits - no; engineers - yes, at least one; janitors - yes, I talked to them; and more importantly, mechanics, assemblers and production line personnel - yes, I talked to them, too.  Engineers have to talk to the people building the airplanes to know if the parts can be made and installed easily.

[HRM]

 

On 11/15/2019 at 11:18 PM, HRM said:

Unless, of course, you do not have a J-bar in your Mooney, then you have that spring to worry about. Then again, has the factory even had any of those for the last few years?

On 11/16/2019 at 5:04 AM, ryoder said:

I agree. I knew when I bought the C for a low price what I was buying. The hull was almost worthless and considered it a freebie, a very slick freebie.

...and no one even took a nibble of my clickbait for starting a manual v. electric gear firestorm!

[Seth]

On 11/13/2019 at 9:10 PM, toto said:

So let's say that the furlough really is temporary, and that Mooney has something amazing up their sleeves...

What is it?

Restarting the M10 line?

Retooling for a turbprop?

Relaunching as a build-assist facility for experimental J models?

Partnership with Tesla and an all-new electric powerplant?

Thank you for stating this thread 

[toto]

22 minutes ago, Seth said:

Thank you for stating this thread 

Sure thing. Given all of the anxiety around the furlough, I thought it would be fun to speculate what game-changing stuff might be happening behind closed doors.

What's the headline out of Kerrville that wins Mooney the 2020 Collier trophy?

[aviatoreb]

I think a Mooney M20 with 21 props would look GREAT!  

This setup is dramatically more efficient as it avoids wing tip vorticity.  Plus you get fantastic redundancy - 21 props! (Reminds me of the old WWII aviatior's joke - "1st officer to Captain - Captain - Engine #4 is on fire!  Captain to 1st officer - Which side?!"

So you run a medium-smaller Diesel engine to run a hybrid electric setup - to power a battery that powers the 20 little electric motors spread out on the wings.  Then you charge the batteries when the engine is running but you can also shut it off in flight for shorter hops. And you are charging the batter in the air, or on the ground - depending.  For take off you are also running the Diesel engine for extra oomph but you have enough electric to do the job in an emergency.

..all on a largely M20 airframe - oh well will need a new wing to house all this stuff - so lets go with a composite wing.

https://www.ainonline.com/aviation-news/aerospace/2019-06-17/daher-airbus-safran-team-ecopulse-hybrid-propulsion

Edited November 18, 2019 by aviatoreb

[Austintatious]

This has been a fun thread... I think that nothing DRASTIC is going to change the situation.  I would think the short list of things that need to be done yesterday would be...

1.  Beef up the landing gear

2.  increase the useful load

3.  SLIGHTLY widen the fuse.. I am talking perhaps 4 inches max.

MAYBE a composite wing that could add some speed and cut manufacturing cost.

 

The other thing I am wondering that might save Mooney as a whole would be a Version of the G3000 with auto land ( I have no idea what this cost) that didnt drive price up too far.  This would even the playing field between Cirrus and Mooney... Imaging having the wife hit the auto land button on a demo flight and watch the aircraft fly its self to a landing.   I think that would sell the airplane.

 

That might not be possible now depending on what that system cost, but in another year it could be half the price.

 

Edited November 19, 2019 by Austintatious

[aviatoreb]

9 minutes ago, Hyett6420 said:

yep the LSA in Europe is doing amazingly well, and the added benefit of the market is that they are quiet, you barely hear a Rotax takeoff, which means that in sound sensitive countries like Holland, Germany etc, they can still fly.  

That's interesting - isn't a large fraction of the noise from an airplane the prop itself?  I mean even an electric airplane with the same prop as my current prop, and same horsepower, would still make a large fraction of its current sound footprint.  So if thats right, then the LSA's must be making lots less noise in part because they are light so they are using smaller and more efficient props - and so the rotax itself might be rather quite but thats not the whole story is my guess.

[aviatoreb]

3 minutes ago, Hyett6420 said:

Sorry you were saying stronger better faster.  This thing is electronic, works out whether he is cycling, running, walking etc and adjusts the oil consistency in the knee accordingly.  You are right we DO have the technology, if we can do this with knees and ankles, aeroplanes are simple.

Is that Steve Austin?  With his bionic bike?  Get that man into the Tour de France!

[aviatoreb]

1 minute ago, Hyett6420 said:

yep i think so, the props are more efficient etc.  but im not an engineer etc so would not the real details but the things that take off form Elstree or Seppe that are Rotax certainly are quieter than my baby, having said that they are also 112 hp etc, but then so is a C152 and that makes a ton more noise even with a silencer on the exhaust.

My guess is that its MOSTLY the prop AND the hp.  A C152 is quieter than a C210.  Because a C210 is pushing 300hp worth of air and a C152 closer to 100hp.  But then the design of the prop is a huge factor too when considering the horsepower fixed.  Eg my own airplane got MUCH quieter when I changed props from an old school 1960's design round tip McCauley to a modern four plane scimitar compliant material MT.  And modern LSA often have all things in their favor - more modern quiet engine, more modern efficient prop (efficiency is also quieter) and low horsepower because the airplanes are light.

[aviatoreb]

4 minutes ago, Hyett6420 said:

oh don't tempt him Eric.  He only took up cycling again two years ago having lost his leg in 1988.  He LOVES it, like a kid in a candy store.

I think there is a piece of paper - a "medical exemption" - that allows pro riders access to otherwise forbidden drugs (some drugs) (in fact Sir Bradley Wiggins is a bit of a scandal for having such a paper for nefarious reasons).  Maybe we get the six million pound Andrew-Austin a medical TUI (paper work) to allow him to compete on an electric bike!  He'll kick butt!

(Actually with an electric bike - I still couldn't keep up in the tour due France - ever see those guys going down hill at 65mph on skinny tires?!  I couldn't do that - and don't forget Im not some dude of the street - I used to be a good track racer - I have a medal from collegiate nationals when I was a young gun).

[AH-1 Cobra Pilot]

14 hours ago, aviatoreb said:

I think a Mooney M20 with 21 props would look GREAT!  

This setup is dramatically more efficient as it avoids wing tip vorticity.  Plus you get fantastic redundancy - 21 props! (Reminds me of the old WWII aviatior's joke - "1st officer to Captain - Captain - Engine #4 is on fire!  Captain to 1st officer - Which side?!"

So you run a medium-smaller Diesel engine to run a hybrid electric setup - to power a battery that powers the 20 little electric motors spread out on the wings.  Then you charge the batteries when the engine is running but you can also shut it off in flight for shorter hops. And you are charging the batter in the air, or on the ground - depending.  For take off you are also running the Diesel engine for extra oomph but you have enough electric to do the job in an emergency.

..all on a largely M20 airframe - oh well will need a new wing to house all this stuff - so lets go with a composite wing.

https://www.ainonline.com/aviation-news/aerospace/2019-06-17/daher-airbus-safran-team-ecopulse-hybrid-propulsion

Do not be fooled by any of this crap.  The companies involved are doing it for either "green" marketing points or subsidies.  Engineering-wise, these designs are simply stupid.  They incur costs with no increases in performance.  Think about running an engine in which all power goes directly to the prop, versus power going to an electricity conversion process, then to the props.  That generator/alternator/etc. has efficiency losses making the system overall a loser.  Also, are two engines more efficient than one?  Of course not, the opposite is true.  Then what happens when you add 18 more?  Yep, even bigger losses.

Hybrid designs make perfect sense for lift, but not for propulsion.  You can pay for the losses of the conversion to electricity because of the efficiency of the distribution system; an engine and four electric motors weigh a whole lot less than four engines.  Plus electric motors are more reliable, more controllable, etc. and best of all, they are easy to tilt.

Therefore, if you really want to talk about the future of aviation, you have to break it down to each of the four fundamental areas of aeronautics: structures, propulsion, controls, aerodynamics, and the human dimensions: avionics and ergonomics.  Propulsion, ergonomics, and aerodynamics are much the same as 1960.  Materials have improved structures, notably composites.  Controls and avionics have progressed rapidly, bringing us the quad-copter and UAS revolution of the past few years.

So, you can extrapolate from where we are, or anticipate new developments.  [That is why I see the 60-year old version of the flying car likely to be the future, although probably a partial tilt-wing design.]  Most of the people working in the field are following the standard design using battery power, and not hybrid.  I am not sure why, but it could be several things:  expectations that battery technology is near a breakthrough, (possible, but not likely), the money offered to develop the ideas is focused on batteries, (probably), they are trapped in the electric paradigm, (no doubt), they are funded and urged on by haters of petroleum, (no question whatsoever).

One more thing: My diesel Jetta gets far better mileage than any hybrid made, and is bigger and more comfortable, and I expect that engine to last many, many, many times as long as the hybrid's battery pack.  The ONLY situation that favors the hybrid is heavy, stop-and-go traffic, but if I shut off the diesel engine during stops, it would probably win again.

BTW, the wing tip vorticies are still there and just as strong.

Edited November 18, 2019 by Ah-1 Cobra Pilot

[Blue on Top]

2 hours ago, aviatoreb said:

My guess is that its MOSTLY the prop AND the hp.  A C152 is quieter than a C210.  Because a C210 is pushing 300hp worth of air and a C152 closer to 100hp.  But then the design of the prop is a huge factor too when considering the horsepower fixed.  Eg my own airplane got MUCH quieter when I changed props from an old school 1960's design round tip McCauley to a modern four plane scimitar compliant material MT.  And modern LSA often have all things in their favor - more modern quiet engine, more modern efficient prop (efficiency is also quieter) and low horsepower because the airplanes are light.

Mostly prop noise, but you also said 112Hp ... so it’s a 4 stroke (and not 2, which are louder).

Why do most people believe the advertising that composites are lighter?  In buckling and compression (the vast majority of an airplane) aluminum is MUCH lighter and stronger ... especially in light airplanes.  In addition, HIRF and lightning protection are easier (in addition carbon has to have an embedded copper mesh).

With Cirrus being the holy grail (on this thread), all y’all might want to do a tap test on the flight controls ... not carbon, not composite but all aluminum.  Only part of a Cirrus that’s carbon are the spars and maybe the paint job (misleading advertising).

Aerodynamics (Mother Nature) haven’t changed since the beginning of time.  Our understanding and analysis tools have gotten better.

[aviatoreb]

48 minutes ago, Ah-1 Cobra Pilot said:

Do not be fooled by any of this crap.  The companies involved are doing it for either "green" marketing points or subsidies.  Engineering-wise, these designs are simply stupid.  They incur costs with no increases in performance.  Think about running an engine in which all power goes directly to the prop, versus power going to an electricity conversion process, then to the props.  That generator/alternator/etc. has efficiency losses making the system overall a loser.  Also, are two engines more efficient than one?  Of course not, the opposite is true.  Then what happens when you add 18 more?  Yep, even bigger losses.

Hybrid designs make perfect sense for lift, but not for propulsion.  You can pay for the losses of the conversion to electricity because of the efficiency of the distribution system; an engine and four electric motors weigh a whole lot less than four engines.  Plus electric motors are more reliable, more controllable, etc. and best of all, they are easy to tilt.

Therefore, if you really want to talk about the future of aviation, you have to break it down to each of the four fundamental areas of aeronautics: structures, propulsion, controls, aerodynamics, and the human dimensions: avionics and ergonomics.  Propulsion, ergonomics, and aerodynamics are much the same as 1960.  Materials have improved structures, notably composites.  Controls and avionics have progressed rapidly, bringing us the quad-copter and UAS revolution of the past few years.

So, you can extrapolate from where we are, or anticipate new developments.  [That is why I see the 60-year old version of the flying car likely to be the future, although probably a partial tilt-wing design.]  Most of the people working in the field are following the standard design using battery power, and not hybrid.  I am not sure why, but it could be several things:  expectations that battery technology is near a breakthrough, (possible, but not likely), the money offered to develop the ideas is focused on batteries, (probably), they are trapped in the electric paradigm, (no doubt), they are funded and urged on by haters of petroleum, (no question whatsoever).

One more thing: My diesel Jetta gets far better mileage than any hybrid made, and is bigger and more comfortable, and I expect that engine to last many, many, many times as long as the hybrid's battery pack.  The ONLY situation that favors the hybrid is heavy, stop-and-go traffic, but if I shut off the diesel engine during stops, it would probably win again.

BTW, the wing tip vorticies are still there and just as strong.

I'm impressed.  I never met anyone with a wind-tunnel and computation fluid dynamics machine all built into their own head.  You are sounding like either an extreme expert in the know - this is all crap, or an old stogie saying everything we ever knew or will ever know was all figured out in the 1960s.  Well that's crap.  Your logic'ing the problem in fluid dynamics is always the wrong solution in fluid dynamics.  Fluid dynamics is quite impenetrable to analogies arguments.  Two engines with props has nothing analogously in common to do with 20 tiny props.  For starters two props need two engines that need big draggy engine nacels to hold the engines.  Tiny props run by tiny electric motors need essentially zero nacels as the motors are embedded in the leading edge of the wings.

Beyond that the way the propulsion works in a 20 prop system ends up being quite different from an aerodynamic efficiency perspective as compared to 2, or 4 engines.  I am not saying this from using my own built in cfd engine as I don't claim to have one - I am simply pointing at interesting field testing research.  Such as: https://spectrum.ieee.org/aerospace/aviation/nasa-remakes-the-airplane-wing-with-electric-propulsion-and-a-whole-lot-of-propellers

verdict is still out if this direction will truly yield a best solution suitable for general adoption but it does look very very promising to me and from reports I have read and heard.  I believe deeply that break through results come from dramatically pushing the envelope, and maybe this will be it - or maybe it will be something else - but something is coming.

If you have competing research to back up your claim, I am very happy to be educated - I only claim this is a very interesting and promising direction.  The possibility of tiny electrics did not exist in the 1960s.  So propulsion engineers could not have imagined what is possible today.

There are dramatic changes afoot.  Just look at the quadcopters/octocopters to see what electric propulsion and digital control theory engineering can achieve.

Yes indeed - propulsion.  You are quite right that there is an efficiency loss in running a generator in a hybrid system.  However running a large engine is inefficient in the first place if you can get away with a small engine.  Imagine an electric system running at a loss.  Charge up some batteries on the ground good for say 2hrs.  Then partially charge them from a smaller engine which only needs to provide say 40% of take off normal take-off power and the electric system supplies the other 60% at take off.  Then run the fuel engine at 30% and the electric system at 30% (of normal take off power) (so the electric system is running at 50% of its capacity).  So on a two hour range you are essentially carrying a fraction of the electric ground recharge to augment the gas motor for higher speed cruise.  If longer range is needed you need to slow down a lot to depend almost solely on the gas motor which you design to be (barely) big enough to keep you safely aloft for a safe landing if you need - if the electric were to fail, but in normal operations you save enough electric at all time for a full take off power go around and climb out as needed.

Separately, the claim is that running 20 tiny props with essentially zero nacels is aerodyamically fundamentally more efficient than any 1, 2 or 4 big prop design.  And this efficiency is meant to offset the efficiency loss of putting a generator in the loop in a hybrid electric concept.

I don't know what will change in the upcoming future but one thing i am sure of is, 1) humans are very very clever, 2) we will find something dramatically new, and I suspect, rather sooner than we think.  Aviation will change dramatically one way or another in the upcoming years.  And our current dino-saur machines will be relics of the past (even if we are still flying them for nostalgia).  Whatever we are flying in 20 years, will be very surprising to us with our current 2019 eyes.

Edited November 18, 2019 by aviatoreb

[aviatoreb]

17 minutes ago, Blue on Top said:

Mostly prop noise, but you also said 112Hp ... so it’s a 4 stroke (and not 2, which are louder).

Why do most people believe the advertising that composites are lighter?  In buckling and compression (the vast majority of an airplane) aluminum is MUCH lighter and stronger ... especially in light airplanes.  In addition, HIRF and lightning protection are easier (in addition carbon has to have an embedded copper mesh).

With Cirrus being the holy grail (on this thread), all y’all might want to do a tap test on the flight controls ... not carbon, not composite but all aluminum.  Only part of a Cirrus that’s carbon are the spars and maybe the paint job (misleading advertising).

Aerodynamics (Mother Nature) haven’t changed since the beginning of time.  Our understanding and analysis tools have gotten better.

I am not saying composite is always lighter when it comes to props.  But in terms what is FAA certified, for my airplane, switching from a McCauley 3 blade prop designed circa 1960's, to my current MT 4 blade which is carbon wrapped wood core, saved 35lbs off my nose.  And that dramatically changed the balance envelope of my airplane and so dramatically changed the "road feel" of the airplane from heavy in pitch to a much lighter feeling airplane.  It feels a lot more like a J now.

BTW as far as prop noise for the 112hp airplanes - I am just guessing it is mostly prop noise - but I could well be wrong.  Does anyone here know the answer for sure?

Edited November 18, 2019 by aviatoreb

[Hank]

2 hours ago, Ah-1 Cobra Pilot said:

Therefore, if you really want to talk about the future of aviation, you have to break it down to each of the four fundamental areas of aeronautics: (1) structures, (2) propulsion, (3) controls, (4) aerodynamics, and the human dimensions: (5) avionics and (6) ergonomics. 

There are three kinds of people in this world:  those who can count, and those who can't . . . . .  

--- not a mathematician, just an engineer whose Fluid Dynamics days are well behind

[AH-1 Cobra Pilot]

22 minutes ago, Hank said:

There are three kinds of people in this world:  those who can count, and those who can't . . . . .  

--- not a mathematician, just an engineer whose Fluid Dynamics days are well behind

Yesss...

four fundamental areas of aeronautics: (1) structures, (2) propulsion, (3) controls, (4) aerodynamics

and the human dimensions: (1) avionics and (2) ergonomics. 

[AH-1 Cobra Pilot]

2 hours ago, aviatoreb said:

Whatever we are flying in 20 years, will be very surprising to us with our current 2019 eyes.

Are the 2019 models that much different from the 1999 models?  I expect to see ideas now in development to be produced, but unlikely to be outrageously different.

There are chances of break throughs, but they are few and far between.  More likely is seeing ideas that exceed the capability to produce at the time, i.e. flying cars.  Fortunately, technology can catch up and make them real, i.e. Dick Tracy's wrist telephone.

[amillet]

Y’all need to watch more “alien” shows on the History Channel. Well soon have anti-gravity propulsion 

[AH-1 Cobra Pilot]

2 hours ago, aviatoreb said:

I'm impressed.  I never met anyone with a wind-tunnel and computation fluid dynamics machine all built into their own head.  You are sounding like either an extreme expert in the know - this is all crap, or an old stogie saying everything we ever knew or will ever know was all figured out in the 1960s.  Well that's crap.  Your logic'ing the problem in fluid dynamics is always the wrong solution in fluid dynamics.  Fluid dynamics is quite impenetrable to analogies arguments.  Two engines with props has nothing analogously in common to do with 20 tiny props.  For starters two props need two engines that need big draggy engine nacels to hold the engines.  Tiny props run by tiny electric motors need essentially zero nacels as the motors are embedded in the leading edge of the wings.

Beyond that the way the propulsion works in a 20 prop system ends up being quite different from an aerodynamic efficiency perspective as compared to 2, or 4 engines.  I am not saying this from using my own built in cfd engine as I don't claim to have one - I am simply pointing at interesting field testing research.  Such as: https://spectrum.ieee.org/aerospace/aviation/nasa-remakes-the-airplane-wing-with-electric-propulsion-and-a-whole-lot-of-propellers

verdict is still out if this direction will truly yield a best solution suitable for general adoption but it does look very very promising to me and from reports I have read and heard.  I believe deeply that break through results come from dramatically pushing the envelope, and maybe this will be it - or maybe it will be something else - but something is coming.

If you have competing research to back up your claim, I am very happy to be educated - I only claim this is a very interesting and promising direction.  The possibility of tiny electrics did not exist in the 1960s.  So propulsion engineers could not have imagined what is possible today.

There are dramatic changes afoot.  Just look at the ^quadcopters/octocopters to see what electric propulsion and digital control theory engineering can achieve.

Yes indeed - propulsion.  You are quite right that there is an efficiency loss in running a generator in a hybrid system.  However running a large engine is inefficient in the first place if you can get away with a small engine.  Imagine an electric system running at a loss.  Charge up some batteries on the ground good for say 2hrs.  Then partially charge them from a smaller engine which only needs to provide say 40% of take off normal take-off power and the electric system supplies the other 60% at take off.  Then run the fuel engine at 30% and the electric system at 30% (of normal take off power) (so the electric system is running at 50% of its capacity).  So on a two hour range you are essentially carrying a fraction of the electric ground recharge to augment the gas motor for higher speed cruise.  If longer range is needed you need to slow down a lot to depend almost solely on the gas motor which you design to be (barely) big enough to keep you safely aloft for a safe landing if you need - if the electric were to fail, but in normal operations you save enough electric at all time for a full take off power go around and climb out as needed.

Separately, the claim is that running 20 tiny props with essentially zero nacels is aerodyamically fundamentally more efficient than any 1, 2 or 4 big prop design.  And this efficiency is meant to offset the efficiency loss of putting a generator in the loop in a hybrid electric concept.

I don't know what will change in the upcoming future but one thing i am sure of is, 1) humans are very very clever, 2) we will find something dramatically new, and I suspect, rather sooner than we think.  Aviation will change dramatically one way or another in the upcoming years.  And our current dino-saur machines will be relics of the past (even if we are still flying them for nostalgia).  Whatever we are flying in 20 years, will be very surprising to us with our current 2019 eyes.

Calculations are not necessary when the general principles rule.  Could you put two 100 hp engines on a J-model and get the same speed?  Do electric companies still erect the smaller wind turbines, or do they install the giants?  Installing more electric motors increases wiring and associated losses, frictional losses, prop losses, mounting hardware, etc.  Focusing on the nacelles is one thing, but wing thickness and/or cockpit area will determine how big of a motor will not add to the nacelle. 

Let us consider a J-model Mooney.  What percentage of drag is contributed by the nacelle?  How big will losses of 20 separate motors be?  Which is more detrimental?  I have not performed these calculations, but you probably know where my money is.

[Andy95W]

3 hours ago, Ah-1 Cobra Pilot said:

Do not be fooled by any of this crap.  The companies involved are doing it for either "green" marketing points or subsidies.  Engineering-wise, these designs are simply stupid.  They incur costs with no increases in performance.  Think about running an engine in which all power goes directly to the prop, versus power going to an electricity conversion process, then to the props.  That generator/alternator/etc. has efficiency losses making the system overall a loser.  Also, are two engines more efficient than one?  Of course not, the opposite is true.  Then what happens when you add 18 more?  Yep, even bigger losses.

Then why are diesel-electric locomotives the industry standard for efficiency at the railroads?

[AH-1 Cobra Pilot]

Just now, Andy95W said:

Then why are diesel-electric locomotives the industry standard for efficiency at the railroads?

1.  They do not worry so much about weight.

2.  They typically work in a very narrow range.

3.  They work better with power delivered to multiple wheels at once.

4.  Electric motors have superior low-end torque.

5.  One big engine powering multiple motors.

[steingar]

What I could never figure out is why everyone is so hung up on diesel.  Yeah, Jet-A is cheap and everywhere, but car gas is cheaper and even more universal.  There just aren't that many places without it.  Not only that, but there are already lightweight aircraft engines that burn the stuff.  Rotate engines burn is just fine, and if there's no booze in it (I think we're the only ones stupid enough to do that) you can run auto gas in the legacy Continentals and Lycosaurs.  Why reinvent the wheel when you don't have to?  The only real disadvantage to car gas is it goes bad after awhile, which isn't a big concern for a training fleet. 

[Andy95W]

9 minutes ago, Ah-1 Cobra Pilot said:

1.  They do not worry so much about weight.

   - then what about a low weight turbine engine powering the electric generator?

2.  They typically work in a very narrow range.

   - kind of like our airplanes that spend the vast majority of their hours between 60-80% power

3.  They work better with power delivered to multiple wheels at once.

  - so multi-electric motor airplanes?  Practically no cooling drag for an electric motor.

4.  Electric motors have superior low-end torque.

  - this is why we have controllable-pitch propellers

5.  One big engine powering multiple motors.

  - see #3, above

So, then, the idea itself is not crap, as you originally posted.  The technology itself might not be mature enough for aviation.  Doesn't mean that won't always be the case.  

My responses are above in italics.