Electric aircraft set to take flight by 2026 under new agreements • Hacker News Board

Re: Electric aircraft set to take flight by 2026 under new agreements

#211

Post by lifeisstillgood » Thu, Jul 15, 2021, 9:53 AM UTC

Symbiote wrote: post #193

lifeisstillgood wrote: post #191

Earlier quoted context omitted.

With all due respect, if they had built airports in the middle of cities, we would all be complaining about why we had to take a taxi to the train station miles from the city centre. The big advantage of the train is being on the property ladder 100 years early.

Most cities that had relatively central airports have closed them (due to noise and pollution) and built new ones further out. Cities continue to build new railway stations and lines, usually underground, to improve access to the centre.

ok so my conjecture: an electric VTOL aircraft will mean cities rebuild airports. Of course it means Kitty Pride will be flying a Electric VTOL ...

But this will free up enormous tracts of land - the railways don't just use land for stations, but the railtrack takes up most of the land (in long strips as it were).

Imagine cities in 50 years, with rail land reclaimed, with Tokyo-like laws that prevent on-street parking (a valuable gift to car owners), freer flowing traffic, more walkable neighbourhoods. There is a lot to unpick.

Re: Electric aircraft set to take flight by 2026 under new agreements

#212

Post by saddlerustle » Thu, Jul 15, 2021, 11:53 AM UTC

Robotbeat wrote: post #100

FabHK wrote: post #94

Earlier quoted context omitted.

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.

Batteries are more like fuel tanks

Re: Electric aircraft set to take flight by 2026 under new agreements

#213

Post by maximus-decimus » Thu, Jul 15, 2021, 12:47 PM UTC

gamegoblin wrote: post #99

I 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 propert…

This me reminds me of Canada's joke political party : the Rhinoceros Party.

They proposed stuff like putting steroids in water supplies to make Canadians stronger. One of their propositions was to build an inclined bike road across Canada so you could "coast from coast to coast."

Re: Electric aircraft set to take flight by 2026 under new agreements

#214

Post by ehnto » Thu, Jul 15, 2021, 3:12 PM UTC

lifeisstillgood wrote: post #211

Symbiote wrote: post #193

Earlier quoted context omitted.

Most cities that had relatively central airports have closed them (due to noise and pollution) and built new ones further out. Cities continue to build new railway stations and lines, usually underground, to improve access to the centre.

ok so my conjecture: an electric VTOL aircraft will mean cities rebuild airports. Of course it means Kitty Pride will be flying a Electric VTOL ... But this will free up enormous tracts of land - the railways don't just use land for stations, but the railtrack takes up most of the land (in long strips as it were). Imagine cities in 50 years, with rail land reclaimed, with Tokyo-like laws that prevent on-street parkin…

I think you're overstating how impactful railway land usage is, in total amount it's definitely a lot but per suburb or area it's not much and it more or less sits next to the rest of the suburb rather than dominating it. It provides far more value than an airport in my opinion. I can walk out my door and 5 minutes on to a train then into the city, there's no way to get a plane from my house to the city.

What you really want to reclaim I feel is roads from cars, we devote insane amounts of land to cars, car parking, and car travel..

The city of Adelaide is an interesting example if you're interested, it's a young city and built an airport 4km from the CBD, which means the CBD can't have tall buildings, the airport has a curfew, noise is a constant hot topic, and it takes up more land than our CBD and most prized suburbs do. It's likely sitting on hundreds of millions worth of real estate, while the train station takes up less than a city block and then the rails weave their way through the rest of suburbia. The most recent Southern Interchange, a car highway interchange, takes up more land than the train station does including it's convergence and junction yard, and all it does is connect two roads together.

The city also tore up all it's rail network when cars took over, and now it can't afford to put the rail back in now that it's proven to be the more sustainable and pragmatic option.

Re: Electric aircraft set to take flight by 2026 under new agreements

#215

Post by thehappypm » Thu, Jul 15, 2021, 3:42 PM UTC

gamegoblin wrote: post #99

I 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 propert…

Gliders don't launch by winch. They are towed up to launch height by powered planes.

Also, gliders are not really able to handle emergencies that well since they are unpowered -- if there's a need to divert or something, they're completely at the mercy of their own gravitational energy. Gliders are usually very safe to fly in because they're very light and maneuverable, and crash-landings are usually OK. That safety net completely evaporates with thousands of pounds of human cargo.

Re: Electric aircraft set to take flight by 2026 under new agreements

#216

Post by nielsbot » Thu, Jul 15, 2021, 4:27 PM UTC

tadfisher wrote: post #131

gunapologist99 wrote: post #128

One of the things that helped Southwest dominate in the short-haul space, particularly in the Texas Triangle, was optimizing "turn-time" with a target of less than 10 minutes to both deplane and board passengers (10 minutes!)[0] I wonder how lengthy charge cycles will affect the viability of fast turn times, especially for the short-haul segments that they're targeting for these new airliners. It seems like they'll n…

Battery swaps could be viable, barring some complications in gate infrastructure and airframe design. Obviously this would be impossible if airframe designers incorporate battery cells in structural members, as some suggest to offset the weight penalty.

The "more info" page on their website says they are ruling out battery swaps, at least for now, since a battery swap would require a mechanical certification every time it was done.

They are swappable though: they explain that used battery packs can be replaced and that used packs can be used for a second purpose with less stringent requirements. For example, an energy storage facility at the airport.

Re: Electric aircraft set to take flight by 2026 under new agreements

#217

Post by eyelovewe » Thu, Jul 15, 2021, 8:57 PM UTC

throwawayboise wrote: post #197

ars wrote: post #171

Earlier quoted context omitted.

> Is this same energy needed to recycle the oxide from the batteries? The energy delivered by the battery in flight, is what you need to use to restore it back to fresh. The more energy you need the better your battery. Why does it need to be specifically solar? Use electric from the grid, and as the entire grid changes over to other power sources so will this.

> Why does it need to be specifically solar? Use electric from the grid, The vast majority of grid electricity is still produced from fossil fuels (at least where I live).

And that must and is changing. Green transport is predicated upon a green grid.

Additionally, a “wasteful” process, like electrolysis of water to make hydrogen, can be usefully inserted at onsite wind generation sites for when the grid isn’t requiring/buying vs sitting idle. When you see large wind turbines stopped and you know that there is a constant stream of wind at 50m above that ridge line it’s simply because the grid is not buying atm. I’m positing that aluminum air batteries are viable for aviation for the same reason.

Re: Electric aircraft set to take flight by 2026 under new agreements

#218

Post by lifeisstillgood » Thu, Jul 15, 2021, 9:05 PM UTC

ehnto wrote: post #214

lifeisstillgood wrote: post #211

Earlier quoted context omitted.

ok so my conjecture: an electric VTOL aircraft will mean cities rebuild airports. Of course it means Kitty Pride will be flying a Electric VTOL ... But this will free up enormous tracts of land - the railways don't just use land for stations, but the railtrack takes up most of the land (in long strips as it were). Imagine cities in 50 years, with rail land reclaimed, with Tokyo-like laws that prevent on-street parkin…

I think you're overstating how impactful railway land usage is, in total amount it's definitely a lot but per suburb or area it's not much and it more or less sits next to the rest of the suburb rather than dominating it. It provides far more value than an airport in my opinion. I can walk out my door and 5 minutes on to a train then into the city, there's no way to get a plane from my house to the city. What you rea…

>>> there's no way to get a plane from my house to the city.

I think I was drinking too much coffee.

But railway is just another road. In fact i suspect that we will find self-driving cars are too hard to put into the mix with human drivers and pedestrians. So we shall build / cordon off roads and end up with railways without rails.

Fascinated by the adelaide example - thank you

Re: Electric aircraft set to take flight by 2026 under new agreements

#219

Post by Tossrock » Fri, Jul 16, 2021, 12:51 AM UTC

throwawayboise wrote: post #198

ars wrote: post #172

Earlier quoted context omitted.

So instead of a fuel truck you have a battery swapper. You'll have to ship the batteries somewhere they can charge/reprocess, but you also need to ship fuel, so it's a 1-to-1 tradeoff (you can ship the batteries by land).

Is it 1:1? There are a lot more KWh in a tanker truckload of jet fuel than in the same volume of batteries.

Not that much more (theoretically) - Al-air batteries could reach up to ~8kWh/kg, which is in the same range as jet fuel's 12ish. Aluminum is also denser than jet fuel, so per unit volume it could be even closer.

Re: Electric aircraft set to take flight by 2026 under new agreements

#220

Post by bertil » Sun, Jul 18, 2021, 7:47 PM UTC

hutzlibu wrote: post #140

bertil wrote: post #14

Earlier quoted context omitted.

Trains are great in many cases, but there’s some limit to tunnels and bridges: you can go from Stockholm to Berlin directly, but Stockholm to Helsinki is harder (that’s actually the destination that the plane is likely to cover); Manchester to Amsterdam is feasible by train in theory, but given the constraints around London and the Channel Tunnel, unlikely to loose its flight connection. Same for Aberdeen to Oslo. Ma…

"ekranoplane " Can't they fly only over flat surface and very close to the ground? That makes them quite unpractical in my opinion.

That certainly limits their universality, but you can imagine a network of fast trains when there’s ground and boats, or something faster on sea, when there’s none, to substitute to flying.

Ekranoplanes use the ground effect, which requires to be close to a flat surface, indeed, but the larger the place, the further you can be. Something the size of a 747 could be a couple dozen meters above the waves and fly smoothly above moderately rough sea.