Why battery-powered aircraft will never have significant range

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tspear

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The physics definition of efficiency is the output divided by the input. By that measure, the Cessna is not terribly efficient; nor are most TC GA aircraft.

But when one considers that a battery powered aircraft to replace that Cessna has not yet been put into production (except for powered gliders with wing spans that are problematic for many users), the Cessna’s “efficiency” at getting private owners into the air for pure pleasure with some CC utility is infinitely higher than the mythical battery powered replacement.

People who want to fly will, for the foreseeable future, be better served by purchasing a Cessna than waiting for a battery powered aircraft.

BJC
I thought you generally read this thread and paid attention. Pipestrel has multiple planes in production which match the C172 or C152 for training flights. And they are not motor gliders, but designed from the ground up as an electric plane.

Tim

Dan Thomas

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Yeah, but you're kind of missing the point. With new stuff we tend to see the downsides as being bigger than they are because the downsides of the stuff we're currently using are things we've gotten used to and don't notice anymore.
Not really. The downsides would have been as I described. Now that we have different motor, battery and controller technology, and rules to govern mining and refining at least in developed countries, the destruction can be limited.

The fact still applies: If we convert wholesale to electric vehicles, we need much more electric power than we have now. One intelligent estimate, to meet the POTUS' requirement of being carbon neutral by 2030, says that we need to design, approve, build and put into service one or two nuclear powerplants every week, beginning back in May already, by 2030. Just imagine that happening. Ha.

And another fact still applies: The vast majority of people do not understand electricity. They have no knowledge of it other than it comes in 110 volts and 220 volts. They don't even know what a volt represents. Amperage and wattage mean nothing at all to them. They believe the nonsense about wind and solar replacing conventional sources. That nonsense is written by journalists and activists who don't understand amperage and wattage either. We have the blind leading the blind.

As I said earlier, I'm not anti-electric. Not at all. I AM against all the misleading hype surrounding this stuff, and against political figures that make decisions without consulting electrical engineers and the like that know about electricity and its sources. Too often it appears that decisions are made after watching the news on the boob tube.

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Dan Thomas

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I thought you generally read this thread and paid attention. Pipestrel has multiple planes in production which match the C172 or C152 for training flights. And they are not motor gliders, but designed from the ground up as an electric plane.

Tim
Range? For training they're OK as long as they can do a one-hour training flight and have the airplane quickly recharged for the next flight. Flight schools go broke if they can't keep those airplanes busy. For most private owners, one-hour flights soon get stale. They want to see more country and go more places with more people. It's the reason why the fresh PPL buys a 150 like he learned in, and soon trades it for a 172 and then a 182 or something that goes even faster/higher/farther.

Aesquire

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The fact still applies: If we convert wholesale to electric vehicles, we need much more electric power than we have now.
Truth. See also post 1439. That world that never happened you describe ( pretty well, although I'd differ in detail ) is what is Needed to make the World Some Want happen. The power generation, not the dystopian hellscape.

The trick is achieving the goal without the Hellscape. That's far beyond this site's focus, but the optimist in me says it's possible to learn from the lessons of the past. The cynic in me points to the towering lakes of radioactive waste where we get magnet stuff, and is pessimistic about that.

So if we had a "Manhatten Project/Apollo Program/Hero Project" to encourage and direct a massive increase in reasonably clean generated electrical power to transition the country ( & eventually much of the planet ) to electric vehicles and great wealth through cheap power, it Could be Done.

You'd have to make me Emperor, to bypass the lobbyists and special interest groups, order the mega projects and allocate the resources, and, I don't want that job.

I don't see that happening near term without a whole long list of changes to education/advertising and maybe REDACTED.... ( remainder of solutions to mankind's problems deleted. )

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BJC

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I thought you generally read this thread and paid attention. Pipestrel has multiple planes in production which match the C172 or C152 for training flights.
Can you point to an independent, credible, flight test report?

I would love to discover that their performance claims are credible, but after talking to their demo pilot at Oshkosh several years ago (hopefully they have made improvements) I discount all of their claims.

Do you have one?

BJC

proppastie

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Never is a long time

tspear

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Can you point to an independent, credible, flight test report?

I would love to discover that their performance claims are credible, but after talking to their demo pilot at Oshkosh several years ago (hopefully they have made improvements) I discount all of their claims.

Do you have one?

BJC
The Electro was certified a year ago; and the design is not much older than that. You most likely were looking at the Alpha.
This is the third or fourth electric plane from Pipistrel, but the first one certified. The previous planes were LSA, or self launched motor gliders.

In this video,
around ten minutes they cover the power and time aspect. Rather interesting, and there is no holding back on the limitations. It has a specific focus, and market.

Tim

tspear

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Range? For training they're OK as long as they can do a one-hour training flight and have the airplane quickly recharged for the next flight. Flight schools go broke if they can't keep those airplanes busy. For most private owners, one-hour flights soon get stale. They want to see more country and go more places with more people. It's the reason why the fresh PPL buys a 150 like he learned in, and soon trades it for a 172 and then a 182 or something that goes even faster/higher/farther.
Very few pilots buy a plane to train in. Rental is the most common. The Electro is designed for easy transition to other planes. So it would be very close to starting with a C152 for the first 30-40 hours of PPL, and then spending one hour to transition and finishing in a C172.

Tim

Victor Bravo

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CopterPack ELECTRIC...... don't know what the range is, but sure looks exciting to fly!!!! ..... anyone got more info?
OMFG... more hyper-dramatic music..... can we just agree to make Millennials outright illegal or something?

The Copter-Pack looks like an interesting and potentially viable configuration. More common sense and less vaporware-looking stuff. The rotor diameter is getting a little more significant, and the individual tilt-rotors seem to work. I'd love to see more, but with the mute button pushed.

BJC

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The Electro was certified a year ago; and the design is not much older than that. You most likely were looking at the Alpha.
Thanks. Looks like they have made significant progress.

Is there more information on the battery’s liquid cooling system that they mentioned?

It would be really nice to fly without engine noise.

BJC

tspear

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Is there more information on the battery’s liquid cooling system that they mentioned?

It would be really nice to fly without engine noise.

BJC
Not public that I can find. And yes, I agree the lack of noise and vibration are very appealing.

Tim

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Vigilant1

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The Electro was certified a year ago; and the design is not much older than that. You most likely were looking at the Alpha.
This is the third or fourth electric plane from Pipistrel, but the first one certified. The previous planes were LSA, or self launched motor gliders.

In this video,
around ten minutes they cover the power and time aspect. Rather interesting, and there is no holding back on the limitations. It has a specific focus, and market.

Tim
Thanks, the video was very informative. The plane was quiet, seemed to work well, and might be fun to fly. The 17 minutes of flying used up 35% of the battery, they apparently did one TO, a stall, and some flying around. At that average use rate, they'd get 49 minutes of flight before entering their reserve capacity.
The plane isn't certified in the US.
I think they are right to concentrate their sales effort on a niche market:
- flight schools conducting primary flight instruction which are located in Europe and which face noise regulations that prohibit weekend IC engine flight ops.

It would be interesting to see the cost breakdown for battery replacement. Their literature says the battery is supposed to be good for 500 hours (not cycles), and they are hoping to get more than that in service. Elsewhere, they say battery life is best when charged to 95% and run down no farther than 35%. I'm not sure how that relates to the 10 minute reserve time that they have apparently built into their planning and software. With the Pipistrel Alpha Electro, the per flight hour amortized cost of battery replacement swamped the fuel cost savings AND the Rotax IC engine rebuild costs. Pipistrel claims the per hour costs of operation of this new electric plane are lower than a comparable IC plane, I'd like to see those numbers.

For now, it appears that most/all of these new electric planes are being bought with government money (in whole or in part). When private flight school operators choose to spend their own money to buy them rather than buying IC engine acft, that will be a significant indicator that the technology is practical, at least in this narrow application.

Nit: Somebody should show that guy in the video how to wear a seatbelt/harness.

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PiperCruisin

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Very few pilots buy a plane to train in. Rental is the most common. The Electro is designed for easy transition to other planes. So it would be very close to starting with a C152 for the first 30-40 hours of PPL, and then spending one hour to transition and finishing in a C172.

Tim
Unfortunately, the cost of new, certified aircraft being what they are (Piper 100i just under $300k), most are purchased for training fleets. Of course$100k of that is probably insurance and $50k the engine. A few years ago I was going to rent a plane, but they would not let me unless I was a student. tallank Well-Known Member Joined Sep 22, 2020 Messages 57 Yeah, but you're kind of missing the point. With new stuff we tend to see the downsides as being bigger than they are because the downsides of the stuff we're currently using are things we've gotten used to and don't notice anymore. Electric cars were the first cars, they predated gas powered cars by about 30 years. And, they have always been with us but their only use was as golf carts. BJC Well-Known Member HBA Supporter Joined Oct 7, 2013 Messages 13,289 Location 97FL, Florida, USA Nit: Somebody should show that guy in the video how to wear a seatbelt/harness. Not a nit: when I saw that, his already low credibility rating went to zero. BJC BJC Well-Known Member HBA Supporter Joined Oct 7, 2013 Messages 13,289 Location 97FL, Florida, USA The 17 minutes of flying used up 35% of the battery, they apparently did one TO, a stall, and some flying around. At that average use rate, they'd get 49 minutes of flight before entering their reserve capacity. They seem to be measuring their endurance is some sort of equivalent (to ICE) hours of taxi, hold (no battery charge consumption) takeoff, regeneration on descent, land, repeat, not actual flight time. Seems reasonable for a training mission comparison, but not for continuous flying. BJC Vigilant1 Well-Known Member Lifetime Supporter Joined Jan 24, 2011 Messages 6,501 Location US They seem to be measuring their endurance is some sort of equivalent (to ICE) hours of taxi, hold (no battery charge consumption) takeoff, regeneration on descent, land, repeat, not actual flight time. Seems reasonable for a training mission comparison, but not for continuous flying. BJC Yes, and I agree the electric plane should get some "credit" for the low energy use in 'idle'. In a C-152, it is common for new students to not need to expend much mental energy on fuel state. Dip the tanks, know that you have enough for the planned flight time, and go fly. Keep an eye on the time and the fuel guages (to the degree they can be read). Fuel management takes a more central place later on in the syllabus. I think, for better or worse, "fuel" management will be more central to the flight experience of students in these planes starting from the first flight. Maybe that will lead to fewer fuel exhaustion crashes over their flying careers, but I think that having one eye always on the battery state might distract from other tasks a student pilot faces. Stick shaker: Hmm. I'd prefer that the student learn to detect an imminent stall from other cues, including the way the controls feel/ respond at high AoA. I wonder if a stick shaker is an appropriate stall warning indicator in a primary trainer. I do see the (near term) safety value, but think maybe there are long-term costs. This is, after all, billed as a dedicated training aircraft. Last edited: EzyBuildWing Well-Known Member Joined Sep 23, 2009 Messages 286 Location Sydney NSW Australia CopterPack vid was filmed at Palm Beach here in Sydney, Australia (I recognize the Beach). Hope CopterPack has more success than the "Martin Jet Pack" IPO which was valued at$105m when it floated on the Australian Stock Exchange in 2015 (Martin Jet Pack subsequently financially crashed and burned when they failed to find a suitable ICE).
Hey, maybe Martin Jet Pack should/will re-invent(re-launch) itself with a new "hiTech-kryptonite-battery-powered version".......
Martin even had a fantastic VR flight-simulator.....
Martin had some very neat hi-tech carbon ducted-fans.....maybe CopterPack can rescue some of them from the scrap-yard.....

Island_flyer

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CopterPack ELECTRIC...... don't know what the range is, but sure looks exciting to fly!!!! ..... anyone got more info?

Nothing other than on the [Australian]` company's website, which also contains nothing but a link to the video. Looks appealing for sure, though endurance is probably no more than 2 or 3 minutes. Relying on powered-lift alone for the whole flight (rather than just TO & Landing, and using wing lift for forward flight) will drain the small battery pack in a hurry. There is some question whether the video is real or cgi. SoloTrek tried something similar about a decade ago. They were able to get 5 million dollars from taxpayers, but nothing ever came of it.
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