Why battery-powered aircraft will never have significant range

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Saville

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Safety:

So some people like to point to fire as a problem for ICE that electrics do not have. Emphasis in the text is mine.


Consumer Alert: Important Chevrolet Bolt Recall for Fire Risk
Owners should park their vehicles outside until further notice

"
July 14, 2021 | Washington, DC

The National Highway Traffic Safety Administration is urging owners of select Model Year 2017-2019 Chevrolet Bolt vehicles to park their cars outside and away from homes due to the risk of fire.
Owners of these vehicles should park their vehicles outside away from homes and other structures immediately after charging and should not leave their vehicles charging overnight, according to General Motors.
The vehicles that should be parked outside are those that were originally recalled in November 2020 for the potential of an unattended fire in the high-voltage battery pack underneath the backseat’s bottom cushion. The affected vehicles’ cell packs have the potential to smoke and ignite internally, which could spread to the rest of the vehicle and cause a structure fire if parked inside a garage or near a house. This recall affected 50,932 MY 2017-19 Chevrolet Bolt vehicles.

Vehicles should be parked outside regardless of whether the interim or final recall remedies have been completed. NHTSA is aware of two recent Chevrolet Bolt EV fires in vehicles that received the recall remedy.

NHTSA opened an investigation (PE 20-016) in October 2020, continues to evaluate the information received, and is looking into these latest fires."

This should put an end to claims that ICE engines can catch fire but electrics do not have to worry about that.
 

tspear

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And, yes, I know guys that thought long and hard about automating towing so one person can do it all... They ended up building powered craft instead of automatic flailing death machines. ( once you've cut loose, that falling tow line might need supervision to prevent taking out landscaping, pets, children... )
I always wondered why a tow rope if you are you going to have a launch system. Make it a sled/cart with a 3ft tow line, would be fairly simple to have it pull the glider much fast and zoom launch. Then return to a charging station next to the runway buried into the ground. Or give it descent wheels, and have it cross grass away from taxi ways on preprogrammed paths. Just need proximity sensors to stop if anything comes near it. Heck, we have vacuum robots that have this level of functionality.

Tim
 

tspear

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@Saville

I must have missed it. Where is all this ICE catch fire stuff?
Does ICE catch fire, yes, but pretty rare. Mostly because we have learned how to handle them. For EV, that knowledge and design does not yet exist.

Tim
 

Dan Thomas

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Safety:

So some people like to point to fire as a problem for ICE that electrics do not have. Emphasis in the text is mine.


Consumer Alert: Important Chevrolet Bolt Recall for Fire Risk
Owners should park their vehicles outside until further notice

"
July 14, 2021 | Washington, DC

The National Highway Traffic Safety Administration is urging owners of select Model Year 2017-2019 Chevrolet Bolt vehicles to park their cars outside and away from homes due to the risk of fire.
Owners of these vehicles should park their vehicles outside away from homes and other structures immediately after charging and should not leave their vehicles charging overnight, according to General Motors.
The vehicles that should be parked outside are those that were originally recalled in November 2020 for the potential of an unattended fire in the high-voltage battery pack underneath the backseat’s bottom cushion. The affected vehicles’ cell packs have the potential to smoke and ignite internally, which could spread to the rest of the vehicle and cause a structure fire if parked inside a garage or near a house. This recall affected 50,932 MY 2017-19 Chevrolet Bolt vehicles.

Vehicles should be parked outside regardless of whether the interim or final recall remedies have been completed. NHTSA is aware of two recent Chevrolet Bolt EV fires in vehicles that received the recall remedy.

NHTSA opened an investigation (PE 20-016) in October 2020, continues to evaluate the information received, and is looking into these latest fires."

This should put an end to claims that ICE engines can catch fire but electrics do not have to worry about that.
Watch how fast they burn: http://www.smalldeadanimals.com/2021/07/16/we-dont-need-no-flaming-sparky-cars-66/
 

Saville

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@Saville

I must have missed it. Where is all this ICE catch fire stuff?
Does ICE catch fire, yes, but pretty rare. Mostly because we have learned how to handle them. For EV, that knowledge and design does not yet exist.

Tim

It's stated sort of the other way around..that electrics don't have the problem that ICE have with regard to catching fire.

I'm surprised you didn't see these posts. Lots of conversation about it - you even addressed it in post #1652 - probably because it was a conversational thing. Try these - just a few:




#1645 - where it is stated that: " none of these problems exist with electric....." which included fires.

#1646
#1649 - as a response

#1652 where you said: or even the propensity to catch fire (all of them).
people took issue with the "propensity part. See 1658
#1658
#1660
#1662
#1664
#1668
#1672
 

Topaz

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I always wondered why a tow rope if you are you going to have a launch system. Make it a sled/cart with a 3ft tow line, would be fairly simple to have it pull the glider much fast and zoom launch. Then return to a charging station next to the runway buried into the ground. Or give it descent wheels, and have it cross grass away from taxi ways on preprogrammed paths. Just need proximity sensors to stop if anything comes near it. Heck, we have vacuum robots that have this level of functionality.
Because we don't have an engine and we need to get more than about 100' of altitude gain on launch, so that we can find thermals and climb out. With enough energy to get to a useful altitude, a ground-catapult like an aircraft carrier is a great way to exceed the maximum allowable speed of the glider, and/or the maximum g-rating on a pull-up to gain altitude. Conventional tows allow the glider to climb away at a predetermined airspeed, just like a powered plane.

Here, watch one:
 

Hot Wings

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Owners of these vehicles should park their vehicles outside away from homes and other structures
Question for those living in Ca:
At one time at least some cities had building codes that required any electric powered vehicle to be stored/parked only in detached garages.
I presume that these have all been removed?

Heck, we have vacuum robots that have this level of functionality
The local Menards is now using a fully autonomous sweep/mop machine ............. mingled with the daily customers.
 

Topaz

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Question for those living in Ca:
At one time at least some cities had building codes that required any electric powered vehicle to be stored/parked only in detached garages.
I presume that these have all been removed?...
I'd never heard of that in the first place, but with the numbers of Tesla vehicles I see every day here, I guarantee there's either no such code now or, if there is, it's the most-ignored law since the invention of the speed limit. 😉
 

trimtab

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I'm still super confused.

Why is it that every photoshopped, SPAC- invested investor trap VTOL design is vying for an all electric future?

Has there been a spat of weekend "This-is-how-you-invest-in-aerospace" seminars that all said electric was the fashionable thing?

Is there something special about electric power that is more appropriate?

I know this thread is long, I've paged through it all. What can't/aren't these designs looking at ICE's instead of electric, when an all electric system is still yet to be made real?

It's clear that the design of electric propulsion aircraft require differences in the approach and offer opportunities as well. I simply don't get how every single freaking design seems to have read the same reference investor pitch deck.
 

Topaz

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IMHO, the "electric VTOL air-taxi" thing is this decade's aviation fad. In the '60's it was the Fairey Rotodyne and similar "feeder" short-range VTOL vehicles. In the '70's it was going to be super-STOL jets feeding big airports from little ones as "air taxis." The '80's brought back personal VTOL, thank you Mr. Moller, as your "personal urban air-transport." In the '90's and early 2000's it was the Very Light Jet (VLJ) that was going to be the "air taxi." Eclipse was the darling of that decade's fad. Now we have e-VTOL.

Nearly every decade has its "miracle advance in air transport," that's going to "free us from the highway and all that nasty traffic." We'll whisk across the sky, arriving at our "big" airport or urban office refreshed and ready to meet a Great New Day. There's always lots of press shouting this technological miracle to the heavens, there's always a crop of new little companies who are going to "disrupt the moribund aviation industry" and every decade's darling becomes the fad investment du jour.

None of them has ever hit success. The economics of short-range "air taxi" services just don't work out when you have such a well-developed, integrated, and economic ground-transportation system. e-VTOL will be no different, IMHO. Just using electric power doesn't change the economics. Even going to autonomous flight and not having to pay pilots doesn't really change it much, because pilots aren't the big cost of the service. Equipment, infrastructure, administration, and liability insurance are the big costs.

This isn't a shot against electric aircraft, or even, per se, e-VTOL aircraft. I think the day is coming when most of the light aviation in the world will be electric powered. The day isn't that far off when we see the first small short-range electric airliners take to the sky. Some of these e-VTOL vehicles are pretty neat, and I can see a niche developing in urban hospital "mercy flight" services, executive transport, and other such "point" usages.

But if I were a betting man, I'd say that, in ten or even twenty years, we're not going all be whisked away from our driveway or local "air transport center" to the big airport or the office, and that while the skies will be "full" of electric aircraft, those aircraft aren't going to look (or be used) terribly differently than we use gasoline airplanes now.

That's my own opinion. Your mileage may vary.
 

Vigilant1

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I simply don't get how every single freaking design seems to have read the same reference investor pitch deck.
I think it all goes back to the $30 toy multicopters and their more expensive cousins. Everyone has seen them, many people surely believe the idea can just be made bigger for 2-6 people. Very quiet, "zero emissions" (Ha!).
"What is a "scale factor?'" "Weight is cubed? " Just get bigger batteries!
 

Aesquire

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Has there been a spat of weekend "This-is-how-you-invest-in-aerospace" seminars that all said electric was the fashionable thing?
Not seminars I've been to, but, yes. Government announcements and speeches and publicity stunts, all tell budding entrepreneurs that no matter what contract/grant/begfundme you w ant to bid/bet on, it better Have the proper buzzwords/technobabble. The mantra changes to keep it fresh and to hide the past fails, but sustainable has hung in a while, carbon free /carbon neutral/ while ripping off soda pop labels, is still popular.

In many cases requests for proposals Now specify either not using the Evil Technology or demands violation of the laws of thermodynamics. If you want a tax break and/or grant money for your automatic grape peeler plant, you Have to use the Holier than you Words laid down in the announcement of the Latest Carbon absorbing buses, or the Mayor's speech before the "first shovel" photo op for the new charging station with a solar shade.

I freely admit cynicism, but pragmatically you can only sell what people want. ( or convince to want ) Flying cars? Only us loons here want that, and politicians sure don't, so sell it as a congestion relieving public transit breakthrough.
 

Aesquire

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Some of these e-VTOL vehicles are pretty neat,...
Yeah!

And some will sell!

I'm just a lotto ticket away from buying Black Fly or EVTOL Raptor II. ;)

There's a meme... The 1967 Pontiac owner's manual told you how to adjust the valves. The 2021 Buick owner's manual tells you not to drink the battery acid.

There are still gear heads. But entry level and even luxury cars today are sold not with torque numbers ( trucks & sports cars still are ) but with Apple phone software. Park itself? Wee! Self driving? Awesome! Saves Kittens? Mom's will love it!

This trend in consumer attitude intersects with an unfortunate fact we flying nuts sometimes forget.

You can't give flying cars to people that can barely drive normal ones. Only a certain percentage can easily think in 4 dimensions of 3D planetary atmospheric flight. Thus flying cars HAVE to be robotic. Or flying taxis.

That doesn't please US, but sells to laymen.

Tomorrow 's airliner I have doubts on ever seeing. Today, I'm a bit excited by the eXenos.
 

PiperCruisin

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This is actually the world's simplest problem. You all just need to go out and become sailplane pilots, and you can fly around using "new green deal" power sources (solar and wind) all day with a little practice.
Of course you still need a relatively expensive tow with an ICE powered aircraft.
 

Dan Thomas

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Jet Pack Speeder looks like it's straight out of Star Wars.....
No, it looks just like a lot of LSAs with Rotax 912s or 914s. Like so:

1626968108028.png

Electric flight has absolutely nothing to do with Star Wars, which is as fictional as you can get. I wish this thread could stick with factual, existing technological developments. Fantasies belong in the games room or the theater, not in the shop or at the airport.
 

trimtab

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Oh, I absolutely love the idea of electric aviation. I think the ability to meet perhaps 10 percent of seat miles for transit and perhaps 30% for drilling holes in clouds would actually help change the world for the better, based on the reliability and other advantages that electric flying could have. Or to dream even bigger, the impact on making GA something that can even hope to exist for another few decades.

What stops me are the napkin calculations. It's just formidable beyond the corner cases and one percentile range of missions in the near future...

...and ICE's have a lot more to offer in the here and now for many missions with significant impacts on emissions and EROEI. I'm on board. I'm skeptical that a time horizon that could shift electric aviation to the 10%/30% mark is attainable without unforeseen massive breakthroughs that would themselves be world changing, let alone attainable within my lifetime.
 

Victor Bravo

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Back to the old old old original title of this thread for a moment.... what if the viable case for electrics is a case where you can accept a fairly short range?

The <50 mile commute from the suburbs to the city center where the majority of jobs are, might be something electrics can be ideal for. The advantages of 'distributed electric' power using eight or ten motors on a wing have already been discussed, and has certain structural and aerodynamic benefits. I'm not talking about VTOL, that is a power hog. I'm again referring to a conventional STOL airplane somewhere between the size of a Caravan, a Twin Otter, or Dash 7. But using the propwash from the multiple propellers (combined with big DH double-slot flaps) to increase the lift significantly.

My point is that something useful and perhaps even "game changing" can be accomplished with what we have and understand now.
 
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