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Electric aircraft set to take flight by 2026 under new agreements
91–100 of 223 posts
Re: Electric aircraft set to take flight by 2026 under new agreements
#92Earlier quoted context omitted.
Most of your point is well made, but electric engines are just as tied to physics, unless I'm missing something? Doesn't mean quality of the control software is still not concerning.
I think what they're trying to say is that the types of electric motors used in vehicles (like switched reluctance motors[1]) typically require a computerized controller that someone has to program, and therefore has an additional point of failure from a software standpoint. However, I'm pretty sure any modern internal combustion engine will have a highly advanced ECU computer too, so this is sort of a non-issue (tho…
My assumption was modern ICE's also had software controllers. You could go with a fully hardware controlled electric motor (electric motors significantly pre-date computers!), but that of course would come with the same kind of trade-offs as fully hardware controlled ICE's (a couple I can think of off the top of my head are inability to change and inconsistent or degrading behavior over time).
Re: Electric aircraft set to take flight by 2026 under new agreements
#93Earlier quoted context omitted.
Large train stations are far more common than large airports in Europe, so you got this the wrong way around.
? I don't think so? Every large city has both a train station and a large airport.
I don't know what you mean by "large" then. In the context of this discussion, I meant train stations served by high speed rail and airports with regularly scheduled commercial service. The former vastly outnumbers the latter in continental Europe.
Re: Electric aircraft set to take flight by 2026 under new agreements
#94Earlier quoted context omitted.
Thank you for bringing up this other conclusion. I still side with Wendover overall. Even if batteries have to be replaced that often now, the technology will continue to improve, becoming both cheaper and more reliable. Computers used to be the size of rooms and break due to literal insects in them.
And it really depends on the chemistry. Some chemistries can last 10,000-100,000 cycles and so the battery may never need to be replaced in the life of the airframe. One thing short haul electric aircraft have going for them is the regulatory requirement to have a 45 minute reserve. That essentially means that the battery will never be cycled to anywhere close to 0% but probably maintain at least 20% almost all the t…
A good rule of thumb (in general aviation at least) is that anything aviation grade is about 10x the "normal" price, or more.
Re: Electric aircraft set to take flight by 2026 under new agreements
#95Earlier quoted context omitted.
Large train stations are far more common than large airports in Europe, so you got this the wrong way around.
? I don't think so? Every large city has both a train station and a large airport.
Definitely not in Germany. There are lots of medium to large cities without an airport, but every one has a large-ish train station with decent connections.
Re: Electric aircraft set to take flight by 2026 under new agreements
#96They talk about regional flight. Does anyone have any sign that battery-powered planes carrying a hundred people will cross the Atlantic, Pacific, or the U.S.? The physics in Tom Murphy's textbook https://dothemath.ucsd.edu/2021/03/textbook-debut suggests it's impossible. I've talked to people at electric plane companies who have offered no hope. I originally thought since we engineered from the Wright brothers to 74…
As others have mentioned, the energy density is a big deal because those planes' fuel accounts for A LOT of their take-off weight. To both illustrate this and point out another potential problem: when a fully fueled heavy, long-haul / high-capacity airliner needs to make an emergency landing shortly after take-off, one of the first things they do is start dumping fuel to reduce the weight (make it more maneuverable)…
An A380 at MTOM has about 15% payload (pax, cargo) and about
40% airplane, so a full 45% fuel. And kerosene has about 30 to 90x the specific energy (energy per mass) as current batteries, so for an electric airplane the numbers would be much worse. (Plus the Airbus doesn't have to carry the fuel it has burned, while an electric plane does have to carry the empty batteries.)
TLDR: Long range air travel with batteries is a long time off.
Re: Electric aircraft set to take flight by 2026 under new agreements
#97Earlier quoted context omitted.
Most of your point is well made, but electric engines are just as tied to physics, unless I'm missing something? Doesn't mean quality of the control software is still not concerning.
I think what they're trying to say is that the types of electric motors used in vehicles (like switched reluctance motors[1]) typically require a computerized controller that someone has to program, and therefore has an additional point of failure from a software standpoint. However, I'm pretty sure any modern internal combustion engine will have a highly advanced ECU computer too, so this is sort of a non-issue (tho…
Ya poorly worded on my part.
Gist is going from internal combustion with a ton of supporting or fully necessary tech to fully electric, fully SW-driven, really skeeves me out given the above testimonial and others like it.
I openly allow it's quite possible that airplanes can't fly these days but for software though.
Re: Electric aircraft set to take flight by 2026 under new agreements
#98Earlier quoted context omitted.
You've got to start somewhere, right? Kudos to the developers of this.
In the 1990s, the idea of electric RC planes were ridiculed as well. I am moderately optimistic that 1:1 planes will eventually follow, as RC electric cars became "good enough" and 1:1 electric cars are a reality now.
I had an electric RC plane in the mid 90s. It wasn't much, just a styrofoam body and pair of electric motors (no flight controls) but it was a cheap and functional RC plane.
Re: Electric aircraft set to take flight by 2026 under new agreements
#99I recently had a pie-in-the-sky business idea and I would love for someone who knows more about the industry why it will definitely fail. I assume it's unworkable for a lot of reasons, but it is just plausible enough to be a fun idea for a sci-fi novel.
Get a fleet of 2-4 seater unpowered glider planes [1]
Get a bunch of rural properties spaced ~100km apart.
Put little glider landing and launch strips on each property. Use a powerful electric winch to launch the gliders.
Develop software that can fly the planes autonomously from strip to strip (I assume this is the really hard part, but I am under the impression that autonomous flying is a much easier problem than autonomous driving?).
You now have the ability to shuttle passengers around your network of airstrips at ~200kph for the cost of electricity used by your winches and maintenance of the glider fleet.
My thought is that the electricity of the winches is pretty minimal and could be served with some locally installed solar panels and batteries, and the maintenance is super low since the gliders don't have many moving parts onboard.
The main use-case would be city-to-city short hops that are currently poorly served by rail. It's far easier to build a string of small airstrips than a whole rail corridor.
This idea came to me when thinking about SpaceX's recent plans to catch their Starship boosters out of the air instead of having landing gear on them. The reasoning is that you can have essentially unlimited mass for ground support equipment, but mass on the booster is precious. So you offload the landing gear from the booster to the ground support equipment, even if it's big and complicated. This idea is like electric aircraft, but you've offloaded the propulsion and batteries to the ground support equipment.
Re: Electric aircraft set to take flight by 2026 under new agreements
#100Earlier quoted context omitted.
And it really depends on the chemistry. Some chemistries can last 10,000-100,000 cycles and so the battery may never need to be replaced in the life of the airframe. One thing short haul electric aircraft have going for them is the regulatory requirement to have a 45 minute reserve. That essentially means that the battery will never be cycled to anywhere close to 0% but probably maintain at least 20% almost all the t…
A good rule of thumb (in general aviation at least) is that anything aviation grade is about 10x the "normal" price, or more.
Fuel isn’t. Jet fuel is basically no more expensive than diesel and sometimes cheaper (no road tax). You can consider batteries basically like jet fuel.