151–160 of 165 posts
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I wonder why there is no fast London - Amsterdam train. It's not that much farther than Paris.
UK border security. On Eurostar journeys all border checks are done at the departure station, and only Paris, Brussels and Lille have the facilities for that. That said, it should be coming this year.
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Sure. How about LNG (liquid methane)? We have enough natural gas to last quite a while. In the far future, hopefully we will have mastered producing kerosene using algae.
LNG tanks are far from lightweight; to keep LNG at room temperature is about 320 atmospheres of pressure. Liquid propane on the other hand is about 8 atmospheres. Mind you at altitude it's around -50 ~ -60 C, but that will only reduce the pressure requirements to approx 100 atm. Also, LNG has about 60% of the energy density of kerosene. SO to use LNG you'd be taking a double whammy, lower density and heavier tanks.
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Based on another article they are not doing 100% electric. They are basically using battery's to replace the alternator/APU attached to the jet engine. That still adds up to a lot of jet fuel, but is only something like 5% total fuel savings.
That's a little more achievable than the "zero emissions airliner" their website promises and would explain why they're talking about going after the A320 market rather than the ATR one (And a 5% emissions reduction over a 10 year horizon is only half what engine suppliers aim for by improved jet technology, though if it's on top of that improvement it would still be very welcome) But if what they're building is an A…
Longer term, they would want to start using electricity for propulsion and ramp that up as batteries improve.
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Sure. How about LNG (liquid methane)? We have enough natural gas to last quite a while. In the far future, hopefully we will have mastered producing kerosene using algae.
LNG tanks are far from lightweight; to keep LNG at room temperature is about 320 atmospheres of pressure. Liquid propane on the other hand is about 8 atmospheres. Mind you at altitude it's around -50 ~ -60 C, but that will only reduce the pressure requirements to approx 100 atm. Also, LNG has about 60% of the energy density of kerosene. SO to use LNG you'd be taking a double whammy, lower density and heavier tanks.
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You've contradicted yourself by saying that batteries are both less and more dense than jet fuel...
LOL energy density is much much lower, but volumetric density is several times higher. Meaning, they take less space for same weight -> airframe can have smaller profile and have less air resistance.
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On the other hand, the majority of the cost of almost any flight is the fuel. Electricity won't be free, but should be considerably less than tonnes of kerosene(I'd love to hear how much less exactly) - which means that obviously airlines can pocket the difference as profit, and they do love that. There's already loads of short connections in EU, so an aircraft like that should be hugely attractive.
> airlines can pocket the difference as profit Air travel is intensely competitive in most areas, and customers generally have very little "brand loyalty" and buy almost entirely based on price. The difference in expenses should result in lower fares. And it is yet unknown whether the extra cost of flying tons of batteries around (they weigh the same when depleted, as opposed to jet fueled aircraft which become light…
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Speaking as someone with no aviation knowledge at all this seems like an awesome idea. The plane could take off with battery packs slung under the wings which are jettisoned and become drones, gliding down to a depot. I'm now waiting for someone who actually knows what they're talking about to point out the flaws. One that springs to mind is the logistics of collecting the drone-batteries and transporting them to be…
I would also add safety and the fact that 70% of our planet is covered in water/not easy to retrieve batteries from.
Though it might be best-suited to short hops between islands, islands and mainlands, or across deep peninsulas. That's a somewhat limited set of markets.
For travel between heavily-populated continental points, ground-based rail would almost certainly be more efficient and practicable, and even in the case of the suggested London-Paris route, there is a ground-based alternative.
Airlines that switch to electrics will have to resolve a logistical issue -- do you switch batteries between flights, or do you need to buy twice as many aircraft, so half are flying and half are charging? I suspect that battery-switching will be the answer, even though the batteries will be a significant percentage of the aircraft's volume.
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
Glancing at Skyscanner for this Sunday there are about 35 flights a day from London to Paris starting from £39 vs 14 trains starting from £151 single. The flights look like they are doing ok.
Currently the shortest LGW-CDG flight is 1h. There is LCY-CDG lasting 1h 20m. For both cities it takes 30 - 60m to get to the airport from central location and you should be there at least 1h before the departure (for a total of 2-3h non-flight time). This makes total travel 3h - 4h30m. For comparison, the fastest train is 2h 25m. I guess you need to travel to and from the train station too, but it's definitely more…
What you're saying. The only reason to take a plane vs taking a train for this distance is the price. Usually planes are way cheaper. But the hassle of taking a plane is really making it a tough sell as you say.
