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PiperCruisin

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Against my better judgement, I'll jump into the fray.

Green or not, I'm a big fan of improving efficiency, anyway it makes sense. I like the idea of electric aircraft for the potential improved reliability and distributed propulsion and reduced cost. Certainly the reliability, cost and energy density are not there yet. But I'm somewhat optimistic. For now, the only place it might be useful is a self-launch glider and/or a hybrid/backup/boost system. If we get a 2.5-3X improvement in energy density, now you have something interesting, but then energy production becomes a limiting factor. Why we don't spend more resources investigating Thorium molten salt nuclear power, I don't know.

As far as subsidies are concerned, maybe they should not exist at all. However, they do and it would be nice to get a pittance to promote and advance general aviation versus all the energy and dollars to send up more space junk (love the GPS, but it made us stupid...this will turn into a "What did Romans ever do for us" moment). More NAsA than NaSA is my vote.
 

Dan Thomas

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c. For now, the only place it might be useful is a self-launch glider and/or a hybrid/backup/boost system.
We've discussed the hybrid idea many times. Nobody, I think, has any idea how to implement it without ending up with a heavier airplane. You still need the IC engine, plus batteries, plus electric motor, plus a sizeable generator.....it gets ridiculous. Light airplanes are extremely weight-sensitive; every ounce matters.
 

tspear

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I like electric/hybrid airplanes for a few possible reasons.
1. The potentially for radically reduced maintenance induced failure. With so many less moving parts, there is less risk in almost every aspect of maintenance.
2. The potentially for longer term cost reductions. Batteries keep dropping in power. The hourly cost in MX on every plane I have owned has gone up every year. At some point electric will be cheaper.
3. A series hybrid, or range extender, is a short term fix for energy density issues. The advantage is primary power and battery power of 30 minutes can basically get you to land safely if the generator dies. This means the genset does not need to be maintained to the same crazy level in theory as the current ICE.

Tim
 

Vigilant1

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I like electric/hybrid airplanes for a few possible reasons.
I agree that electric power may someday be a practical power source for many aviation use cases. But today? No, it isn't. You've named some advantages electric power will bring, but the energy densitty limitation of present batteries just overwhelms every other consideration.

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3. A series hybrid, or range extender, is a short term fix for energy density issues.
In practice, it is not a practical fix. Find a use case, get real weights for the needed IC engine, associated generator, needed battery, electric motor(s), and cabling. Be realistic with the power requirements (e.g need the ability to execute a pattern and a go-around even immediately after takeoff, etc) and you'll see that the weight of a series hybrid is not comparable to an IC engine alone. To address reliability issues, a second IC engine still weighs less than the series hybrid, and provides much more mission flexibility.
 
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Hephaestus

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and you'll see that the weight of a series hybrid is not comparable to an IC engine alone.
And that's where the super lightweight microturbines come in.

But due to the turbine in the name the costs are pretty extreme. But... Jaguar has some for next year's supercar hybrid - so we should see some options coming up.
 

Dan Thomas

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I like electric/hybrid airplanes for a few possible reasons.
1. The potentially for radically reduced maintenance induced failure. With so many less moving parts, there is less risk in almost every aspect of maintenance.
It's a more complex system, introducing more possibilities for maintenance mistakes. And there are MORE moving parts, not fewer. As a mechanic, I (and every other mechanic) found the simplest airplanes presented the least hassles and maintenance errors, and the more complex had to be watched carefully during maintenance so that some error didn't get overlooked. And more complexity meant more time and more cost.
 

Hot Wings

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In practice, it is not a practical fix. Find a use case, get real weights for the needed IC engine, associated generator, needed battery, electric motor(s), and cabling. Be realistic with the power requirements
Plenty of other threads here about this. Old rabbit hole. :D;)

I agree when it comes to conventional aircraft and even training flights. We just aren't there yet. But.............
There are corner cases where pure electric and even hybrid make sense today - even from an engineering perspective.
Part 103s, gliders and planes with missions like my future AV-361 can benefit from a hybrid system. The weight of the system is competitive with a pure ICE in the power class and there are some advantages. Neither simplicity or ease of design are one of them.
 

RonL

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There's no way I can explain the connection between this and an electric airplane, but there are possibilities.


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pictsidhe

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Plenty of other threads here about this. Old rabbit hole. :D;)

I agree when it comes to conventional aircraft and even training flights. We just aren't there yet. But.............
There are corner cases where pure electric and even hybrid make sense today - even from an engineering perspective.
Part 103s, gliders and planes with missions like my future AV-361 can benefit from a hybrid system. The weight of the system is competitive with a pure ICE in the power class and there are some advantages. Neither simplicity or ease of design are one of them.
I looked at a hybrid for my 103 to give good takeoff power with a cruise size (and weight) engine. Had some advantages, but would be a PITA to engineer. Simpler it is not. I'm going for a bigger ICE instead. If I was bothered about range, I may consider it worth the effort.
 
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