Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Startup Announces Plan for 150-Seat Battery-Powered Plane

electrek.co

Post reply on HN
Print view View original

11–20 of 27 posts

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#11

Post by dexterdog »

logicallee wrote: post #9
kogepathic wrote: post #3

Earlier quoted context omitted.

> Airplanes can be used on fixed trips of known distance, and shooting for the 150 passenger size seems ideal for the limitations that electric would entail Yes and no. The major problem for electric planes (apart from the fact that the energy density of the best batteries is piss poor compared to Jet-A) is the weight does not decrease throughout the flight. This means you need more robust landing gear as the MTOW an…

I find it very hard to believe that landing gear isn't fine with landing under full starting weight -- after all what if you need to land shortly after taking off for some reason? (return to leaving airport.) So I "plane" don't believe it's an issue. Regarding fuel weight not decreasing - could hydrogen fuel cells be burned and the resulting (h2o, water vapor) simply be left as contrails? Reference: https://www.quora…

First, that would be an emergency landing. Second, they would likely dump the fuel.

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#12

Post by dexterdog »

kogepathic wrote: post #3
djrogers wrote: post #2

This is so clearly a great opportunity for electric tech - Airplanes can be used on fixed trips of known distance, and shooting for the 150 passenger size seems ideal for the limitations that electric would entail. Think SF-LA, there are probably 1000 flights / week between these two areas, and some of those could be handled by a plane like this.

> Airplanes can be used on fixed trips of known distance, and shooting for the 150 passenger size seems ideal for the limitations that electric would entail Yes and no. The major problem for electric planes (apart from the fact that the energy density of the best batteries is piss poor compared to Jet-A) is the weight does not decrease throughout the flight. This means you need more robust landing gear as the MTOW an…

Making planes is not hard. Making big, safe planes is very hard.

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#13

Post by scrooched_moose »

logicallee wrote: post #9
kogepathic wrote: post #3

Earlier quoted context omitted.

> Airplanes can be used on fixed trips of known distance, and shooting for the 150 passenger size seems ideal for the limitations that electric would entail Yes and no. The major problem for electric planes (apart from the fact that the energy density of the best batteries is piss poor compared to Jet-A) is the weight does not decrease throughout the flight. This means you need more robust landing gear as the MTOW an…

I find it very hard to believe that landing gear isn't fine with landing under full starting weight -- after all what if you need to land shortly after taking off for some reason? (return to leaving airport.) So I "plane" don't believe it's an issue. Regarding fuel weight not decreasing - could hydrogen fuel cells be burned and the resulting (h2o, water vapor) simply be left as contrails? Reference: https://www.quora…

The difference is fatigue. I'm sure the landing gear can support the full weight, but how many times?

The gear may be rated for 20 uses at full takeoff weight or 100,000 uses at empty weight.

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#14

Post by phmagic »

The plane does look sexy.

I'm not clear on how this works out economically.

Gas turbines are more efficient than electric at high altitudes and long distances. So the regional hops are where this could make an impact.

IMO regional hop planes are less efficient at moving cargo than trains (or hyperloops). America just doesn't like high speed trains for some reason.

Between trains and jet turbine planes, I'm not seeing where electric passenger planes like this make a huge image.

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#16

Post by SigmundA »

bsilvereagle wrote: post #7

" If batteries don’t get dramatically better in the next decade, we design our plane as a hybrid with electric motors, like a Volt. It still has great cost savings as compared to today’s planes, and it doesn’t require massive battery advances. If batteries do get a lot better in the next decade, our plane is fully-electric and has fantastic cost savings. See chart #2 below; a near-future jump to a chemistry like Li-M…

Seems like this would be a step backward in efficiency. Direct mechanical drive is more efficient than double conversion at cruise speeds. Even the Gen1 volt connected engine to wheels at highway speed because it was more efficient, Gen2 they went to a more conventional hybrid design like a Prius with mechanical power splitting because its more efficient even at lower speeds.

Airplanes are even simpler using variable pitch props the ICE just runs at it most efficient rpm with no or minimal transmission and nearly zero mechanical losses.

Also a hybrid design is heavier than a direct mechanical and airplanes would seem to not benefit from hybrid advantages such as regenerative braking and 0 rpm torque.

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#19

Post by daenney »

dexterdog wrote: post #11
logicallee wrote: post #9

Earlier quoted context omitted.

I find it very hard to believe that landing gear isn't fine with landing under full starting weight -- after all what if you need to land shortly after taking off for some reason? (return to leaving airport.) So I "plane" don't believe it's an issue. Regarding fuel weight not decreasing - could hydrogen fuel cells be burned and the resulting (h2o, water vapor) simply be left as contrails? Reference: https://www.quora…

First, that would be an emergency landing. Second, they would likely dump the fuel.

They wouldn't, necessarily, be able to dump fuel. Most modern short to mid-haul aircraft like all of the Boeing 737's and the Airbus 320 series don't have a fuel dump system. It's only long-range twin-jets that are likely to have a fuel dump system and in some cases that's actually depending on what the customer ordered.

> (a) A fuel jettisoning system must be installed on each airplane unless it is shown that the airplane meets the climb requirements of §§25.119 and 25.121(d) at maximum takeoff weight, less the actual or computed weight of fuel necessary for a 15-minute flight comprised of a takeoff, go-around, and landing at the airport of departure with the airplane configuration, speed, power, and thrust the same as that used in meeting the applicable takeoff, approach, and landing climb performance requirements of this part.

http://www.flightsimaviation.com/data/FARS/part_25-1001.html

Re: Startup Announces Plan for 150-Seat Battery-Powered Plane

#20

Post by jcoffland »

saosebastiao wrote: post #10

I get it, fuel costs are huge for airlines. But fuel costs are still small beans compared to capital utilization. I hope they have a feasible plan for recharging and getting back in the air without significant delays. That is a very significant amount of energy to shove into a plane in such a timeframe. If recharge times are anywhere close to an hour, this idea is DOA.

You could swap batteries.
Post reply on HN