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The largest electric aircraft just flew [video]

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Re: The largest electric aircraft just flew [video]

#381

Post by throwaway2037 »

labcomputer wrote: post #353
tonyarkles wrote: post #216

Earlier quoted context omitted.

Typical reserve requirement is 30 min for a turbine aircraft (45 for piston). Given the 125 mile battery-only range and the probability that it flies at at least 200 kts (230 mph), it’s pretty unlikely to hit even a 30 min reserve on only batteries. I like the design, I think they get the problem and have a decent solution for it

> Typical reserve requirement is 30 min for a turbine aircraft (45 for piston). For private, yes. For airlines, the requirement boils down to basically enough fuel to "fly to the intended destination as scheduled, then loiter for XX minutes, then fly at normal speeds to a pre-designated alternate, land". For short flights, that means the fuel loaded at departure can be more than twice what is actually needed to get f…

    > You can use it for ~125 mile flights, and remain 100% electric on ~95% of flights.
The video says that in the United States about 1 in 1000 flights are diverted from their intended destination airport.

Re: The largest electric aircraft just flew [video]

#382

Post by throwaway2037 »

bluGill wrote: post #287
phire wrote: post #163

Earlier quoted context omitted.

> and should not happen on well planned flights You make it sound like it is acceptable for a badly planned flight to have a fuel emergency. It is not. If there is a fuel emergency (or the plane lands with less than 30min of fuel) there will be an incident investigation that treats the situation as serious as if the plane had crashed. If the investigation discovers it was nothing more than bad planning, (at minimum)…

Badly planned flights should not happen. Pilots who don't carefully plan their flights end up dead quickly. Lack of fuel is one of the easier to handle things that can go wrong from bad flight planning.

Can you give an example of a "badly planned flight"? And did local regulators agree with your opinion?

Re: The largest electric aircraft just flew [video]

#383

Post by dyauspitr »

PaulRobinson wrote: post #280
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.

Not much airport shenanigans in the small island hopping nations and the fjords this is aimed at. 125 miles in 2 hours is assuming flat, straight, high-speed, low-traffic roads. Sure, people might not use these to fly SFO → LAX or back, but they likely will use them to go ABZ → LSI, and the "check-in and security shenanigans" are, errr, quite relaxed, compared to what you might be used to at JFK... There's a ton of s…

300 miles is very viable for a lot of routes. Not 125 though.

Re: The largest electric aircraft just flew [video]

#384

Post by mbesto »

ddlsmurf wrote: post #375
mbesto wrote: post #361

Earlier quoted context omitted.

> but they're very frequent. Yet you state their frequency as some sort of statistical fact. Your anecdotal experience doesn't make it any more or less true.

and you are refuting with even less justification. I told you how to check for yourself if you actually cared about veracity. Best of luck trying to get funding to publish something academic anti-CCP though, but I'd love it if you did. Also this is just a conversation, not an academic debate

> I told you how to check for yourself if you actually cared about veracity.

Which means nothing. You still dont get my point.

> Also this is just a conversation, not an academic debate

It can be both.

Re: The largest electric aircraft just flew [video]

#385

Post by dghlsakjg »

Toutouxc wrote: post #371
dghlsakjg wrote: post #338

Earlier quoted context omitted.

I understand that energy and instantaneous power draw aren’t the same. I’m working with the numbers given: over a megawatt of power draw, and the price of energy in kilowatt hours. I’m not saying that they are flying on 100kw. I’m saying that using absurdly optimistic - unrealistic, really - pricing they have alln energy budget of 100kwh to use for the entire flight of 27 min. That means that average power consumptio…

> You are saying that they took off with a normal amount of power for a plane that size, then cruised around using an amount of power (45kw) that wouldn’t keep a two person plane 1/20th the weight airborne. No, I’m not saying anything about 45 kW, you’re, again mistaking kW for kWh. > Citing drag from a Tesla is kind of irrelevant because the whole way an airplane works is by creating lift via drag. That’s already in…

You were arguing for the 100kwh derived from $5 a few comments up. Now you are arguing for low hundreds of kWh?

So you are now in agreement that $5/100kwh is unrealistic? That was my whole point the entire time.

Re: The largest electric aircraft just flew [video]

#386

Post by bluGill »

throwaway2037 wrote: post #382
bluGill wrote: post #287

Earlier quoted context omitted.

Badly planned flights should not happen. Pilots who don't carefully plan their flights end up dead quickly. Lack of fuel is one of the easier to handle things that can go wrong from bad flight planning.

Can you give an example of a "badly planned flight"? And did local regulators agree with your opinion?

My dad dreamed of being a pilot and when I was a kid he subscribed to the flying magazine (or something like that I don't remember that name.) every single issue had the last story being "I learned about flying from that" and nearly every single one was a case of bad planning, usually a case of flying into bad weather because of the bad planning.

Re: The largest electric aircraft just flew [video]

#387

Post by bluGill »

Toutouxc wrote: post #339
bluGill wrote: post #317

Earlier quoted context omitted.

> I am now on vacation That is the key here. People go all over the world for vacation. However vacations are not normal life (at least not for the vast majority of people), and can be ignored. In normal life people have a place they live, and they have people they visit. When looking for a place to live they consider the real trips they take (not cutting through corn fields), and that guides where they move to. Peop…

I have no idea what point you’re trying to make or how is my vacation “the key here”. I’m visiting a regular Czech town that just happens to be almost exactly 125 miles from another regular Czech town (the one where my parents live), and I used those two particular towns as an example of how 125 miles can be a pretty big deal in Europe (or really anywhere in the world that’s not the US).

Let me try again while the day has gone by. You're not the only one who doesn't understand my point.

The correct measure of distance is not something like miles or kilometers. It's time, that is minutes or hours.

Thus your 125 mile distance if that had really good roads that could be an hour and a half trip by car. If you had high speed rail that could be under an hour. If you were a fighter pilot and had permission to use a fighter drive at max speed just minutes (that is costs and the environment is not a concern). Each of those enables something very different about the life of the people who live in those areas.

Thus, when you say it's a lot more than two hours for you to make that trip because of whatever reason, I can in turn infer that this is a major trip that people are making and in turn they're not making it very often. It is fine to make that as a vacation, but if you were to move there permanently, that means you're going to have to find all new friends. You can still go visit the old friends, but it's not something you're going to do very often.

If you just said it was an hour and a half, then if you got an offer to move that far, say a better job, it wouldn't be nearly as big a deal because you could still go visit your friends and family fairly often. It's not something you would do every day and so you would have to find some new friends, but you could also keep your old friends.

If somehow you could do that trip in half an hour, then you could just move there and it would not change anything else about the rest of your life to move. Everyone you currently know, all your friends and family, they're easily within reach of just going to visit anytime you feel like it.

Re: The largest electric aircraft just flew [video]

#388

Post by coin »

misterderpie wrote: post #91
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.

For anyone looking for the reference, it's stated at 10:16 [0] [0] https://youtu.be/nM86DBOqgPM?si=BdoZzp1Dxa4S3C_9&t=616

Yes it's super misleading. All the marketing and title is calling it "electric" where in reality it's a hybrid electric-gas airplane with a 125 mile electric range. Aviation uses nautical miles yet they advertise 125 statute miles so the number seems bigger (125 statute miles = 108.62 nautical miles).

It would be like Toyota marketing the Prius as an electric vehicle, then buried in their presentation sneaking in the gas propulsion. Same with Chrysler Pacifica (32 mile electric range).

Re: The largest electric aircraft just flew [video]

#389

Post by phire »

throwaway2037 wrote: post #382
bluGill wrote: post #287

Earlier quoted context omitted.

Badly planned flights should not happen. Pilots who don't carefully plan their flights end up dead quickly. Lack of fuel is one of the easier to handle things that can go wrong from bad flight planning.

Can you give an example of a "badly planned flight"? And did local regulators agree with your opinion?

LaMia Flight 2933 - https://en.wikipedia.org/wiki/LaMia_Flight_2933

The pilots took exactly enough fuel to reach their destination. They didn't have enough fuel to divert to an alternative airport. They didn't even have the mandatory 30min of reserve fuel. They did not account for a minor holding pattern just before landing (ironically, because another plane had a fuel leak).

The crew failed to declare a fuel emergency, and crashed 18km from the airport. They had only been in the hold for 10 min when their engines ran out.. they were very short of fuel, the pilots knew they were short. They should have diverted (or declared a fuel emergency) almost an hour earlier, but they didn't want anyone to know how close they were cutting it.

Re: The largest electric aircraft just flew [video]

#390

Post by walrus01 »

IAmBroom wrote: post #328
walrus01 wrote: post #159

The interesting part to me is that a lot of current electric aircraft development seems to be waiting for battery technology to catch up. They're far ahead in terms of the motors, propeller, electric propulsion control system. The limitation is the battery capacity. Companies like Joby, Archer and others also seem to be taking the huge gamble that battery density in Watt-hours per kilogram will SIGNIFICANTLY increase…

As noted elsewhere in this thread: probably ain't gonna happen. Battery energy density increases are tapering off. We may already be close to the maximum possible (where close means within a factor of 2 or so).

I feel inclined to agree with this based on my observation of batteries that can actually be purchased (not hype PR things where people announce a miracle 450Wh/kg batttery).

The electric VTOL companies in this niche that survive may ultimately end up with something like a small series hybrid that uses Jet-A fuel and has a single gas turbine engine driving a generator, along with batteries, and electric propulsion motors.

Electric motors and gas turbine in use to lift off, consistent lower fuel consumption gas turbine -> electrical use during level cruise flight, then another burst of amperage and use of batteries during the landing phase.

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