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They discuss quite a bit of this in the video. I actually thought it was a decent walk through of why they're targeting the space they're targeting, and how th
by horsawlarway 12d ago
They discuss quite a bit of this in the video. I actually thought it was a decent walk through of why they're targeting the space they're targeting, and how they're thinking about exactly these problems.
Some items to consider from the video
1. short flights spend an large amount of energy simply having the engines running during taxi to/from the runway.
2. Take-off also consumes much more fuel than cruising.
3. 1 & 2 combine to push airlines to prefer larger & larger planes making longer trips when using fuel (it's how they're managing that 45.9 seat mile number - it get much worse for shorter trips).
4. They're already pushing the 400kwh/kg range for batteries (I believe he makes an offhand comment in the video that they're using 8 packs, with roughly the capacity/weight of 4 tesla battery packs - which would put their batteries in the ~4k lb range if we estimate by teslas pack weights. They are likely pushing to go lower than that. I think it's not crazy to consider they're targeting a production weight ~50% below your guess - in the high 3000s)
5. On top of fuel savings, one of his more compelling points is that maintenance on their engines will be much, much lower. Jet engines are expensive to service, maintain, and repair (thousands of parts, complicated designs, extreme operating conditions). Their motors are basically 450kg dc motors - it's a giant drone motor mounted on an airframe.
6. they seem to have quite a bit of interest from existing airlines (ex - united) so apparently this does seem compelling to them.
7. He quotes a $5 take-off cost in electrical power. Something like an Embraer ERJ-135 uses ~20 - 30 gallons of jet fuel for the same thing (~$100). If they target a plane that's doing very frequent takeoffs/landings, operating costs could be considerably lower, not just lower.
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Personally - I don't know if they'll make it work, but it's definitely an interesting play, with more real thought put into it than most attempts I've seen.
- class3shock 12d ago1-3. Agreed 4. Remember my predicted number is on the low side of how much juice they would need. Of course they get much better efficiency than a conventional jet on taxi and takeoff, so maybe it ends up being closer to what you are saying. I wish they had some more hard data. 5. Yep, commented on this in another post but even just removing takeoff wear and tear on a conventional engine would be big. 6. I would take that with a big dose of salt. United has a deal with Boom (a complete fraud of a company in my view) to purchase planes. So maybe not the best metric. 7. I haven't done the math but the $5 takeoff doesn't pass the smell test for me. $5 doesn't buy much juice (50 kWh? So like a gallon of jet fuel?) and getting a 30k+ lb plane to cruising altitude is not trivial. "Personally - I don't know if they'll make it work, but it's definitely an interesting play, with more real thought put into it than most attempts I've seen." Totally agree, which I never thought I would say about an aerospace startup.
- mdnahas 12d agoA businessman I talked to said that United is investing in smaller airplane manufacturers in hopes of breaking the Boeing-AirBus duopoly. Thus, giving commitments here and to Boom Supersonic.