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The largest electric aircraft just flew [video]

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Re: The largest electric aircraft just flew [video]

#131
post #16

Interesting decision to build the whole aircraft instead of the propulsion system only. I wonder what the decision process was between retrofit of existing turboprop frame vs. build from the ground up? I would expect the level of effort and certification to be much higher building from scratch even though you get complete control.

Judging by the seats, perhaps making it as light as possible. Existing airframes are relatively light but let's be honest, they aren't trying to save 500g here and there when they have massive jet engines to get everything airborne.

https://www.latimes.com/business/la-fi-travel-briefcase-unit...

Re: The largest electric aircraft just flew [video]

#132

Earlier quoted context omitted.

Yup. On a 737 they can put about 8k pounds per wing. Even little planes like Cessnas have wing tanks.

Wow wow! Might see planes just a smidge differently now :)

In sailplanes we add up to around 200 litres of water to wing tanks in single-seat gliders (empty weight typically around 280kg) to improve the high speed performance (typically up to 270 km/h these days) and ability to fly comfortably in turbulence.

It's surprising what you can fly formation with, even without an engine [1] :-)

https://www.youtube.com/watch?v=G0icOICQLTc

Dumping (most of the) water before landing:

https://www.youtube.com/watch?v=I4Yv-V7eozk

[1] this particular glider does have a small engine for takeoff, but maximum speed with the engine extended is 180 km/h and here they are flying at 280 km/h.

Re: The largest electric aircraft just flew [video]

#133
post #15

Earlier quoted context omitted.

Can I be the one to make the obligatory train comment? Moving hundreds of people 500 miles in comfort, using only electricity, is also a VERY solved problem.

Man, I’d love more trains but we can’t act like the infrastructure necessary to support them, if not present, is very challenging to develop. Even ignoring land acquisition (which is a big thing to ignore in populated areas where a train would most benefit the population), there are simple things like road crossings, other infrastructure crossing, etc. In this case an airplane may be simply a lower friction solution.

The biggest costs and sources of delays to building high speed rail in the UK are legal challenges from people who don’t want any construction to take place anywhere near them.

Re: The largest electric aircraft just flew [video]

#134
post #87
post #83

Is this EV or Hybrid? The founder seems to sneak in the word "hybrid", around 1m30 mark in the video below. https://youtu.be/nM86DBOqgPM?si=5unXLmPxk6M_kmuN&t=86 Note: not being negative, I just want to ensure I understand correctly since the title might imply something else. Update: confirmed, it does use aviation fuel. > "The airplane will also include a reserve-hybrid configuration, consisting of two turbo generat…

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.

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.

Re: The largest electric aircraft just flew [video]

#135
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.

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.

Re: The largest electric aircraft just flew [video]

#136
post #83

Is this EV or Hybrid? The founder seems to sneak in the word "hybrid", around 1m30 mark in the video below. https://youtu.be/nM86DBOqgPM?si=5unXLmPxk6M_kmuN&t=86 Note: not being negative, I just want to ensure I understand correctly since the title might imply something else. Update: confirmed, it does use aviation fuel. > "The airplane will also include a reserve-hybrid configuration, consisting of two turbo generat…

The X1, which is what flew, is all electric. The ES-30, their proposed product, is hybrid.

Re: The largest electric aircraft just flew [video]

#137
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.

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.

Regular aircraft fly with enough fuel to change into at least one other airport in an emergency (ideally two).

That aircraft would need a very large battery to do that, and it's way more efficient to have some burnable fuel there that you'll never actually use.

Re: The largest electric aircraft just flew [video]

#138
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.

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.

Regular aircraft are required to have enough fuel to be able to divert to the alternate airfield in their flight plan plus all the margins for taxiing and waiting for a landing clearance. If a plane is low on fuel they can declare an emergency and get priority over other traffic, but that obviously is disruptive and should not happen on well planned flights unless something pretty significant happens after takeoff.

Re: The largest electric aircraft just flew [video]

#139

Earlier quoted context omitted.

Could you imagine the (rather justified?) NIMBYism for all the airports required for commuter flight? If rail can’t be done, flight definitely won’t fly.

Curious, would electric flight be significantly quieter such that airport noise is significantly less of an issue? Or is the noise from turbulence through the air or something? I honestly would think they'd be minimising turbulence anyway for energy efficiency.

Most of it is due to turbulence. But that doesn't mean that a different engine can't make the plane have a completely different noise profile.

Re: The largest electric aircraft just flew [video]

#140
post #93

Earlier quoted context omitted.

Surprised they are not using linear opposed piston crankshaftless generators to make an extended range EV aircraft. Smaller, lighter, simpler, cheaper, and more flexible about fuel. https://www.youtube.com/watch?v=NeG4zLlFkak Linear engine starts around 11:19

Turbines are extremely reliable and well-understood in aviation propulsion

This! Anything unproven makes the flight certification process longer. They already have to get their electric side certified, might as well make the backup generator as easily certified as possible.
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