90-seat Elysian airliner: 800-1,000 km range on batteries alone | Hacker News Reader

90-seat Elysian airliner: 800-1,000 km range on batteries alone

newatlas.com

22 pointsclouddrover23 comments

1000km is pretty good, but there are some caveats. There are still major technical hurdles, such as the problem of burning batteries. They will not have the mass budget to protect the battery as well as they do now. What can only be dangerous for cars in tunnels is deadly for an aircraft. It is well known that burning planes do not fly for long.

The wings and propellers suggest that the plane will be slower, well outside the transonic range. The study on the startup's website says they will fly at Mach 0.6 or about 650km/h.

At this speed, the fastest commercial trains are faster for the first 1100km. That's a problem if your plane can only go 1000km. You will have to compete directly with trains, which will definitely be cheaper to run.

Electric planes still have a place. Trains have high upfront costs, cannot realistically be built everywhere, and are unpopular in North America. In other parts of the world, however, with functioning long-distance public transport, this aircraft will have a hard time. It will be interesting to see what aircraft technology will be able to establish itself in the future.

> In other parts of the world, however, with functioning long-distance public transport, this aircraft will have a hard time.

Agreed, but I’d add that high functioning public transport often isn’t economical in areas of low population density or high geographical difficulty.

For example, electric planes could be really useful for hopping and the Irish Sea and the Scottish Highlands & Islands.

Theoretically bridges/tunnels with trains could do the same job but in practice the journey volumes make it hard to justify the capex required to build them.

I’m not convinced that turnaround time is as big of an issue as it’s made out to be.

The point of low turnaround time is to lower cost. But EV airplanes are likely to be much cheaper to operate, so they don’t need low turnaround time to be economically competitive.

If they take an hour to charge they could be moved to a separate area where they don’t incur high fees from the airport for taking up valuable space at the gate.

And the primary market for these planes is going to be small local airports, that don’t have gate fees as a factor at all. The main problem for those airports is they don’t get utilised enough because planes are too expensive to operate and too loud to have frequent take-offs/landing close to town anyway.

I’m also guessing that these planes will be able to charge fast enough to get to 20min turnaround time for many routes. They won’t be discharged to less than 20% when landing, and many routes can probably be handled with 80% charge. 20-80% charge in 20min is absolutely feasible.

Making the batteries easily swappable could be a way to address both the charging and safety issues: should a battery catch fire while the plane is in the air, the pilots could have the option of jettisoning the affected battery bank, worst case converting the plane into a glider.

I’m not sure that dropping flaming batteries from the sky will be very popular with those on the ground.

As a last option to save a plane, dropping a flaming battery is just fine. If this happens too frequently, battery packs will need adjustment.

I can fly 1000km with batteries alone too...

Just take a glider, fly it along thermals all day and night, and keep a watch battery in your pocket while you do so.

The longest continuous glider flight is over 3000km by the way.

The difference is gliders are slow. This electric plane will also be slow because it is half way to a glider.

Slower is OK if it’s faster than land based transport and can use local regional airports.

Some electric planes are much more quiet when taking off. They can also be cheaper to operate. They will probably enter markets where you might drive 10-30m to a local airport and fly directly to another local airport near your destination. Rather than driving an hour to a large international airport.

Norway is a perfect example of a good market. It has a large network of small local airports. The main issue for them is operating costs. Given the geography it’ll almost always be faster to fly, even if the plane is slower, but it’s often expensive. And having noisy planes taking off right next to small towns every hour would be annoying.

I dont understand why people are talking about charging times. You would think that swapping batteries would be a trivial fix for that problem. It could even be done by large batches of relatively-easy-to-handle battery packs. You could even preload all the luggage together with the battery packs in packages get hung/inserted in the plane from underneath in minutes.

Battery swapping didn’t make sense for electric cars because the battery itself constituted so much of the cost of an electric car.

It’s cheaper to buy two electric cars than to buy one + a spare battery, taking into account the labour cost of performing frequent battery swaps.

I’d guess similar economics applies to electric planes, although I admittedly don’t have a strong source to cite.

If it was such a no-brainer solution why nobody is doing it? Clearly there must be more to it.

I know very little about aviation. I thought that jet engines were way better for flight than propellers, but it seems that in order to provide power from batteries this plane is forced to use propellers instead.

Is that a major drawback? Or is that difference not as important as I ignorantly assumed?

Turboprops are more fuel efficient than jet engines with the trade off of slower cruising speed. On short distances this isn't a problem as less time to hit max speed when you take into account climbing and descending for landing.

ATR now owned by Airbus makes turboprop airplanes for regional airlines. They seem to be working on a hybrid electric model which should incorporate some electric motor features https://www.atr-aircraft.com/presspost/atr-paves-way-for-nex...

All you need to do to make a plan fly is move air backwards. Propellers and jets both do this. They are each more efficient at different weights and airspeeds. They aren’t fundamentally different.

Turboprops are awesome and underrated. They have some advantages over jet engines such as faster response times (they can angle the blades instead of having to rev up RPMs), easy reversing (no pushback mule needed), and higher efficiency. They fill a niche really well.

I wonder how long these will be allowed to fly after first battery fire if they use lithium chemistry. It is one thing to move burning car around, but passenger plane on most airports? It could take hours or even days to extinguish one and move to save location. Disturbing the normal operation for the whole time.

So even if there is not loss of life, the disruption of operations could be too significant for many of the bigger airports to allow operation.

What makes you think a battery fire is likely at all?

High quality EVs are already extremely unlikely to catch fire. Much less likely than ICE cars of similar model and age. And those cars are exposed to relatively rough conditions (accidents, debris on the road, etc) , and the battery packs aren’t closely monitored.

For a plane, the QA of the battery pack would likely be better to begin with. They’d have much stricter procedures for monitoring the battery packs for possible abnormalities. And they’re unlikely to be exposed to a physical accident.

By the time they hit the skies (2030+) our experience with batteries will also be better. It’s obviously possible to ensure a battery never spontaneously ignite. Most battery packs, by far, never do. We’ll probably have a better understanding of the triggers of freak spontaneous fires.

Even in the ridiculously unlikely event of a battery fire I’m pretty sure it can be handled. People make out EV battery fires to be impossible to handle but the fire departments in places with high EV concentration has it pretty much figured out now and consider EVs to be less problematic than ICE. (Norway, Netherlands)

I'm just considering couple hundred of these operating daily. Then if single one has to abort take off and evacuate at end of runway. That might close off relatively big airports runway for good bit. Likely causing significant secondary economic damage.

Also ensuring that everything works perfectly and never fails is not very simple thing.

When Ba38 crashed at Heathrow it was blocking the runway end for 3 days

  What makes you think a battery fire is likely at all?

I'm half kidding, but Boeing's experience with the 787. Their solution was more or less to just seal the battery off a bit better.

Oh the doubts.. anyway I think you can be sure in that industry that this would be considered ahead, and not suddenly realized after the first fire.

Curious for reference for that it would take days? There seems to be a lot going on in getting better to put such fires out efficiently (despite the eventual advances in different battery techs also).

Just extrapolating from electric cars. If those can flare up after fire has been put out after significant time. I don't see why even larger battery banks on plane would not do exactly the same thing.

Solutions with cars is either submerge them in water or cover them with fireproof blankets. But scaling those to larger size is quite a challenge.

Presumably they'll do everything to ensure that fire is localized to small part of a battery. There's much more space to separate them than in car. Maybe we'll even see some mechanism to eject batteries out as last resort, since fire is going to weaken airplane structurally anyway so it's better to do it in controlled manner.

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