Why battery-powered aircraft will never have significant range

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Rhino

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If they don't catch on fire why do commercial aircraft have fire suppression equipment installed?
Nobody claimed they don't catch on fire. It was simply stated that they don't "all" have a propensity to catch on fire, as was claimed. And last time I checked, most commercial aircraft use turbine engines, not ICE.
 

Rhino

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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.
Yes, but you know wind technology is still in it's infancy. And Icarus proved they have a propensity to melt. :)
 

Dan Thomas

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If they don't catch on fire why do commercial aircraft have fire suppression equipment installed?
Air Transport category, not commercial. So many lives at stake there. And how many airliners fly their whole lives---decades---and tens of thousands of hours with never a fire?
 

tspear

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@Rhino

You make my point for me. The whole OP said electric can never happen (the range limit I mentioned). Everything in that article was a comparison to ICE.
And your interpretation backs up my point.

The reality is we have had close to a hundred years to gain tribal knowledge about ICE propulsion. We have built significant processes in place to address the known issues with them. e.g. in my plane partnership we IRAN one mag every year, alternating. We put the battery on a tender every month.....

No such tribal knowledge exists for electric planes; and I see how painful it is building such knowledge for Diamond Jet-A diesel engines. When you combine the current technical limitations of electric planes, combined with a lack of knowledge on how to solve issues, it is going to be a rough road, and a likely a long one.
The only real advantage electric planes have on this front, significantly fewer parts; this likely means there will be a lot less tribal knowledge required.

Tim
 

Dan Thomas

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And last time I checked, most commercial aircraft use turbine engines, not ICE.
Technically, a turbine is an ICE. Internal combustion. A steam engine is an external combustion engine; the combustion does not directly cause the heating and expansion of the gases within the operating mechanism.

The piston engine uses the Otto cycle. The turbine uses the Brayton cycle.
 

raumzeit

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Lithium batteries at current state-of-the-art can easily keep a tank of diesel warm enough for a long time without needing giant piles of them; and one doesn't need crazy discharge currents to do it - so pretty safe even in cold temps. Which makes 2-cycle turbodiesel viable for the sky perhaps; at least beyond just niche German WWII spyplanes. An interesting thought.
 

blane.c

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Air Transport category, not commercial. So many lives at stake there. And how many airliners fly their whole lives---decades---and tens of thousands of hours with never a fire?
The point is however, how many don't. There is plenty of video on airplanes on fire which of course is fine if you ain't the one in it because then you can point at statistics and such and pull out your suspenders and puff your chest and stuff or you know talk louder than anybody else. I fart now and leave the room.
 

Saville

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Why ICE engines quit...... a really great vid..... none of these problems exist with electric.....
NONE of those problems exist with electric? Did you even watch the video?
Again this is more of the hyperbole that relegates posts into the dustbin.

1) The very FIRST category was "Mechanical Failure" at the 5:15 mark.

You're trying to tell us that electric propulsion DOES NOT have mechanical failure? Sheesh.....

The data used in the video was 2018, NTSB stats. That gave 1224 Accidents of which 117 were powerplant accidents.

That's 9.5% of all accidents. 117 is not a whole lot of accidents. So airplanes are not falling out of the sky with the engines aflame like some suggest.

2) If an engine stops because the pilot didn't put in carb heat that's not an engine failure that's pilot error. Same for fuel exhaustion. And fuel starve, fuel exhaustion and fuel contamination account for most of the engine failures.

Are you trying to tell us that NO pilot of an electric powered plane will run out of juice before landing due to pilot error?

3) Crankshafts fail due to prop strikes (around the 15:15 mark).

Are you trying to tell us that there will be no prop strikes with electric aircraft which then damage or destroy parts of the electric motor? You are still spinning a prop with lots of torque and rpm and there's still a prop shaft on bearings.

4) 17:15 mark - failure because bolts were not torqued enough.

Are you trying to tell us that no mechanic will make a mistake and therefore there will be no failures due to bolts on the electric not properly torqued?

So there's four categories of failure that electrics share with ICE. And many of those can be avoided by the recommendations at the end of the video.

The same will occur with electric propulsion units: you will get lots of failures due to pilot laziness or error and many of them will be avoidable.

I don't think you watched the video at all and/or thought about what was said.

So no an electric Pipistrel won't throw a rod. But it shares many failure modes with ICE. And your last example - magneto failure - well your entire propulsion system is electric so if mags can fail electrically so can any part of your electric system.

To other posters:

Tspear: I don't recall any poster in this thread saying "ICE is perfect".
And ICE engines do not have a "propensity" to catch fire. Are you even aware of engine fire stats?

Just more hyperbole that gets posts ignored and makes electric proponents sound like Elmer Gantry

Later you say:

"No such tribal knowledge exists for electric planes" which is true.

But at the same time the number and flight hours of electrics are so miniscule as compared to ICE - and the tech has not shaken out yet - such that the stats on failures aren't worthy of the name.

More to the point, the failure modes have not been discovered.

Anybody trying to tell us that electrics will fail less often is engaging in pure conjecture.

You simply do not know.


Dan Thomas: Correct when you say "If electric airplanes get the same level of maintenance as so many ICE airplanes, they will crash just as often. Electrical stuff is no more forgiving of neglect than any other stuff." Which was the main point of the video.

Lots of us here have no problem with electrics should they turn out to provide the performance and safety that match ICE.

But when guys like EzyBuildWing try to tell me that electrics ARE safer than ICE because they don't have con rods I have to just laugh.
 

Topaz

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There is a lot of needless grandstanding on both sides. I see this also in electric car discussions. Gasoline vehicles are a flaming disaster just waiting to happen, parts falling off because of all their "complexity." Electric vehicles are a flaming disaster just waiting to roast you with their lead-brick-like batteries, assuming they can even get down the block without running out of charge. Gasoline vehicles are the best thing invented by the Hand of Man and always will be - proven, timeless, known. Electric vehicles are the Wave of the Future and you're a doddering grandpa if you can't see it. Go get back on your horse.

We all need to stop being cheerleaders and haters and let things happen as they will. Electrics will get better. Gasoline vehicles are pretty darned great, and will be doing what they've done so well for many years to come.

The moment you make this propaganda and personal, you're out of bounds on HBA. Let's all take it down a notch please. If you can't stay involved in this discussion without "taking exception to what that guy said about 'x' vehicles," maybe duck out of this thread for a few days and come back with a cooler head.

Don't be this guy:

duty_calls.png
 

Rhino

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@Rhino

You make my point for me. The whole OP said electric can never happen (the range limit I mentioned). Everything in that article was a comparison to ICE....
From the OP:

"Current aircraft-rated battery systems do about....

...we see that existing planes (Antares 20, FES) obtain about half that rate...

...If we look at the best possible today...

...Even with the currently non-existing Li-O batteries...

...Bottomline; for range hybrids will be the future..."

The OP very clearly establishes he thinks the limitations are only effective at this time, and he very clearly indicates he thinks electric has a good future. There was no article. There was a video, but the OP didn't create it. He merely said it did a good job of summing up the current limits of electrical propulsion. If you're trying to make the OP responsible for anything else in a video he didn't create, please provide some evidence to back that claim up. I'm certainly open to hearing it if you have it, but it wasn't in the first post.
 

Rhino

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...I fart now and leave the room.
Monty Python?

We can find videos of electric or ICE vehicles burning, but that proves nothing and does nothing for any of us. There are pros and cons for both sides, but we go nowhere if we insult each other or make unsupportable claims. We can discuss this without being ridiculous and without attributing opinions to others that they haven't stated. Don't make me quote Rodney King, please.
 

tspear

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@Saville

No, with electric planes no pilot will ever run out of energy. The reason is because with such a pitiful range, they never leave the airport area. (I could not resist).
I do not believe I ever said ICE engines catch fire, if so I would hope it was taken out of context because I do not believe that is a real issue. I do believe that ICE have failure modes, which we have spent a lot of time learning to prevent and as a result have many "rituals" designed to prevent them. Just think about sumping the tank as one example.

@Rhino

Read the title of the first post.

Tim
 

Aesquire

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Yea -- I'd need a solution for getting rid of the burning batterys, without
touching up the countryside ; before i'd ever consider going electric.

Bille
Rocket boosters to throw the burning batteries into the Pacific.

Downside is you might hit a whale. ( see whale rescue scene in movie Hancock ) And give the Navy more UFO infrared footage.

And if you are, say, in the Inyo mountains, you might need a two stage booster and the first stage might drop on LA.

And it makes your project unaffordable. And too heavy to fly. And...

Seriously, the fire hazard for Lithium chemistry batteries appears ( please correct me if I'm wrong ) to be mostly during charging, Crashes, and immersion in salt water.

The immersion part was demonstrated by a lot full of Fiskars that got wave/wind flooded in New Jersey. A typical Cessna probably won't catch fire if dropped in salt water, but probably will leak gasoline, and certainly will need extensive repairs if possible. The structure & corrosion problems are more or less identical for electric and nuclear planes.

I'll add that Electric cars have some unique challenges for corrosion control, like requiring non conductive Freon substitutes in the HVAC system to prevent unwanted galvanic corrosion.

Crashes are a fire hazard in anything with high density energy storage. Even ( tested in buses ) high rpm flywheel power storage! We don't have a big enough data base to compare confidently.

Charging is a problem. The better ( and heavier/complex/expensive) battery sensor/control hardware And software reduces the risk to the level most find acceptable. My Sainted Mother unplugs the toaster when not in use for fear of fire, yet plugs her Prius in with few qualms.

My guess is charging your electric motor glider is more dangerous than you filling a gas tank, but less than a smoking beer drinking idiot filling his tank then mason jars to stock up. ( or the folk filling plastic bags in their trunks... See pipeline hack panic buying. )

So for me, safety is always a consideration, but batteries are just another factor. It's money & mass that make my choice for power plant in a motor glider.

One possible combination not discussed much is the trade/compromise of a fairly high power ( but much lighter than a 4 stroke of equiv. power ) electric motor & a ludicrously small battery for 1-2 thousand foot climbs out of tiny field/back yard. For example, in a trike optimized for soaring.
 
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wsimpso1

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Moderator Mode ON:

+2 on Topaz' comments above. Note that he is a Moderator here.

This is the second moderator note to all of you today. Treading close to the line on personal attacks and making multiple posts that way is just as much a personal attack as a single statement that clearly busts the CoC. If the moderators spot any more thinly veiled personal comments on this thread, we will lock it. Let's stick to the topic of thread and its applicability to our little airplanes, and then we may continue the lively discussion of the pros and cons of electric power and how we may or may not get adequate range from it. Yeah, we can drift into safety, but let's remember that thread drift using anecdotes needs background to become actionable data.

Keep it civil, keep it on the topic, keep it off the personalities.

Moderator Mode OFF.
 

Bille Floyd

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I like this part Best :

...
One possible combination not discussed much is the trade/compromise of a fairly high power ( but much lighter than a 4 stroke of equiv. power ) electric motor & a ludicrously small battery for 1-2 thousand foot climbs out of tiny field/back yard. For example, in a trike optimized for soaring.
In effect , that is my goal for the mission ; power-UP
a few thousand feet, and shut down the engine/motor, fold the prop
and go soar for HOURS !!!!! :)

I'm getting kinda Old , for that foot-launched Hang gliding stuff , because
the feet don't work , like they use to ; but i'm SOOooo addicted to soaring
that i can Not quit.

I am not apposed to electric flight, but it's important to me that if
things go Bad, that i don't affect anyone but myself ; I accept the
risk associated with my flight time, but the people on the ground
did not sign up for any risk associated to my addiction.

Shorting out a fully charged LIPO battery, is also a reason
for fire ; had that happen with a T-Rex-450 RC helicopter
once, because the speed-control developed a short. The
LIL helicopter , went down in flames ; woulda bin Awesome
if it didn't belong to me . :(

One thing i was thinking for a possible arrangement for a battery
pack , was to connect the LIPO's in series for the volts
needed to run the motor, but use only 1/5'th
the total KWH needed for the full pack, on each series ; if a short
develops on any of the 5 batteries, i could drop it on a
10-ft SS cable, till the fire goes out, then discard them completely
with a small parachute. If that happened --- i'd still have the full
voltage to run my motor; but only 4/5'th of the KWH . For me, an ICE
is still a cheaper and lighter way to go, (for now) ; but that might change
in the future.

Bille
 

Dan Thomas

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In Bertorelli's video, the cause chart includes 6% carb ice and 29% unknown. As he says, carb ice is suspected in the vast majority of that 29% because nothing can be found defective in the engine or fuel system and it runs just fine. Other articles I have come across say the same thing.

I have long said that carb ice is the biggest single cause of engine failures. Maybe 20 years ago AOPA had an article that put carb ice at the top of the factors list for engine failure. If that 29% was all carb ice, it would mean that as many as 35% of the failures were due to ice, far outpacing any other factor. Even 30% would be huge.

Cars, when they had carbs, had carb ice until someone figured out how to automatically prevent it. The incoming air's temperature is measured by a simple thermal vacuum valve that bleeds air into the tiny vacuum line that closes the air intake and opens a port that brings heated air from around the exhaust manifold. The air going into the carb is maintained above 70°F. The carb is also mounted on a manifold that has exhaust heat conducted into it.

Yeah, we could do that with airplanes, but it would rob the engine of a lot of power, which we can't afford, and it would advance the danger of detonation. The car's engine seldom has to deliver full power, and when it does the vacuum falls off and that carb heat valve closes to give the carb ambient air. In an airplane the manifold vacuum is low at anything much above idle, so you'd have no carb heat in cruise.

Anyway. Get to the point, Dan. Management of carb ice is the pilot's responsibility and he's supposed to be trained for it. Obviously, too many don't get the whole concept. The point is that it is not the fault of the ICE.
 
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Aesquire

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Bille, the "good news" is that today it's cheaper to just buy a 2 stroke paramotor engine and have the power, range, and flexibility of choosing how full/big to make the fuel tank. So toss in a gallon or two, fly, and if you want to "recharge" that is fast and relatively easy.

I'm happy that the electric motor glider is now almost affordable. But it's still fringe product that requires massive compromise and big pockets to buy. ( I anticipate threads here on recycling car battery packs, if there aren't already ) I'm just too cheap to make that choice in 2021.

The electric Airliner might happen this century. The power density means there will also be pocket rail guns.

I'd bet on catapults and big nets for the Mythical Urban Commuter air system instead of anything currently advertised. But I'm cynical, and have watched as those services went away when they lost profitability, and then never came back because NIMBY rules.

There are already fringe loons flying human cuisinart multi-prop drone based toys. So I find myself in the same position I was in during the late 70's, wondering if flying is going to be banned because of backlash in a culture that's increasingly intolerant.
 
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