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The largest electric aircraft just flew [video]

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Re: The largest electric aircraft just flew [video]

#231

Post by D_Alex »

ddlsmurf wrote: post #214
ragebol wrote: post #207

Earlier quoted context omitted.

I read new truck sales in China are about 30% electric and climbing. Apparently it does make sense for them

What China does hardly indicates economic sense, and you can be sure you won't hear about the down sides or failures. They already very agressively hide car lithium fires but they're very frequent. Economics over there are mostly investment driven with a large dose of ideology and vanity, not demand driven. You can see it everywhere including the massive amounts of empty housings for example

>They already very agressively hide car lithium fires

But you found out... how?

Re: The largest electric aircraft just flew [video]

#232

Post by mmanfrin »

IrishTechie wrote: post #195
giancarlostoro wrote: post #182

Earlier quoted context omitted.

Honestly, I'd feel better knowing it has a reserve system in case there's any issues, even if the batteries have more than enough power, beats having it and never using it, than needing it and suffering as a result.

Do current aircraft have a backup in-case their fuel tanks run dry?

Yes, they also have ramjet turbines which generate electricity from the movement of the plane on a backup circuit.

Re: The largest electric aircraft just flew [video]

#233

Post by ncruces »

ragebol wrote: post #207
ddlsmurf wrote: post #197

Earlier quoted context omitted.

Yes, it doesn't even make sense to make electric trucks, let alone airplanes. Or they'd be mostly battery.

I read new truck sales in China are about 30% electric and climbing. Apparently it does make sense for them

Due to Iran, they're cutting oil/fuel imports 30% YoY, and consumption by the transportation sector by 5~10%.

Re: The largest electric aircraft just flew [video]

#234

Post by gblargg »

luma wrote: post #135
werdnapk wrote: post #134

Earlier quoted context omitted.

So what do regular aircraft do when they run out of fuel? They require a forced landing. Aircraft fly with a buffer of fuel though to avoid such situations, so why can't an electric aircraft fly with a similar buffer on it's range? ie. Always fly less than the current charged range of the aircraft.

Simply put, batteries are heavy.

Something like 1/30 the energy density of liquid fuel. Plus unlike fuel, a discharged battery weighs virtually the same as a charged one.

Re: The largest electric aircraft just flew [video]

#235

Post by boelboel »

pkulak wrote: post #98
boelboel wrote: post #27

Earlier quoted context omitted.

It's not about moving hundreds of people, it's about moving 30-100 people. Many places don't have the demand or physical possibility for a railway. If this wasn't the case there wouldn't be so many short distance flights.

> Many places don't have the demand or physical possibility for a railway. This I don't get. I've seen rail stops in the smallest towns, where the train stops for 30 seconds to let a couple people on or off. Places where even the smallest airplane makes no sense at all. Not 30-100, 1-2.

Old lines which have some more riders on other stops I imagine. You only need to maintain the rail which has been laid 150+ years ago.

Re: The largest electric aircraft just flew [video]

#237

Post by fmpfmp »

class3shock wrote: post #155

Doing some math. Regional jets get somewhere around 45.9 seat miles per gallon (1). So 30 seats, going 125 miles would take around 80 gallons of jet fuel. This is likely low because all the jets listed are bigger and likely flying longer flights that are more efficient but just go with it. Jet fuel has a specific energy of 12 kwh/kg and a density of 6.7 lb/gal (2). So 80 gallons of jet fuel is 536 lb, or 243 kg, and…

Also consider that an empty battery weighs the same as a charged one. Whereas empty fuel tanks don't.

I wonder how annoying this is for the engineers to stay within landing weight limits (MLW)

Re: The largest electric aircraft just flew [video]

#238

Post by golem14 »

giancarlostoro wrote: post #182
luma wrote: post #87

Earlier quoted context omitted.

Hybrid after the first 125 miles, total range 500 miles. Their problem is diversions - an incident at the destination airport may mean an passenger aircraft may need to land at an airport which could be a couple hundred miles away. The hybrid powerplant throws the fuel efficiency numbers off so goal is not to run it unless needed, but they could not get certification without it.

Honestly, I'd feel better knowing it has a reserve system in case there's any issues, even if the batteries have more than enough power, beats having it and never using it, than needing it and suffering as a result.

The real benefit really seems to be that the electric motors have a much smaller failure rates than mechanical ones running near their top rpm. The hybrid motor can run at a much optimized RPM, so the idea is that this will improve the overall safety margin of the overall design. I could be wrong, but that's what the video said.

Re: The largest electric aircraft just flew [video]

#239

Post by theodric »

keiferski wrote: post #203
dyauspitr wrote: post #164

Earlier quoted context omitted.

Unless they have a whole new airport and flying experience, I don’t think a lot of people are going to fly just 125 miles. That’s less than two hours of driving. It would be 2 hours of just airport shenanigans much less the flight itself.

Could be useful for hub and spoke type systems, where you fly from a smaller city to the main hub, and catch a connection from there. Even then there are lots of flights in Europe that are between cities less than 1 hour apart. This idea generally makes more sense in Europe than the US, I think.

Electric propulsion would eliminate the local environmental impact of emissions justification for the short-haul flight bans that are floated and/or implemented [1] from time to time in Europe. It makes sense to spray less jet/avgas exhaust when possible. Of course, if the ban reasons include noise abatement or evil conspiratorial machinations, they're still on the table ;)

[1] https://en.wikipedia.org/wiki/Short-haul_flight_ban?#Overvie...

Re: The largest electric aircraft just flew [video]

#240

Post by Toutouxc »

shuwix wrote: post #227
Toutouxc wrote: post #181

Earlier quoted context omitted.

> 125 miles … That’s less than two hours of driving. I don’t know where you live or what you drive, but I just punched in a destination 200 km away as the crow flies, the Alps are in the way and I’m looking at five hours of driving. Also, water.

That's nothing. I was crossing Himalaya's by crawling at even slower speed. Dayuuum, ... you're smart.

I am, but it doesn’t take a genius to know that 125 miles as the crow flies is “less than 2 hours of driving” between like 6 specific pairs of destinations in the whole world.
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