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Startup Announces Plan for 150-Seat Battery-Powered Plane

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

#21

Post by logicallee »

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.

This doesn't pass the smell test for me. The vertical velocity when it lands it not very great - if landing gear has no trouble supporting the plane during taxi off under full weight, I find it preposterous (and reckless) that it would be insufficient for landing. The idea that planes routinely dump fuel if they have to circle around and land immediately after take-off is absolutely ridiculous to me: if there is nothing wrong with a plane, highly combustible fuel is far safer inside than outside of it.

I found your suggestion so ridiculous I Googled "do planes dump fuel" and got this top answer

http://aviation.stackexchange.com/questions/29232/do-airplan...

"Do airplanes dump fuel before landing?"

For which Google picked the summary: "There have been many explanations given but ultimately the answer to your question is "No, aircraft do not dump fuel prior to landing unless it is absolutely necessary.""

Reading that page: as a rule fuel is not dumped!

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

#22

Post by saosebastiao »

jcoffland wrote: post #20
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.

That does seem to be the current model for fast recharges. It's not out of the question, but these are going to be extremely big batteries and the planes, batteries, and auxiliary equipment need to be designed for it up front. The thing with planes is that design is extremely expensive and design costs are expected to be amortized over a long lifecycle, which means that a technical constraint today could end up being very costly if the constraint goes away in the near future.

Wright Electric likely knows all this and is working on it...a partnership with a low cost airline would surely inform them of what is needed for success. I'm just complaining that the article is not very substantive.

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

#23

Post by nradov »

logicallee wrote: post #21
dexterdog wrote: post #11

Earlier quoted context omitted.

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

This doesn't pass the smell test for me. The vertical velocity when it lands it not very great - if landing gear has no trouble supporting the plane during taxi off under full weight, I find it preposterous (and reckless) that it would be insufficient for landing. The idea that planes routinely dump fuel if they have to circle around and land immediately after take-off is absolutely ridiculous to me: if there is noth…

You're not seeing the whole picture. Airliners don't routinely dump fuel during normal operations. However, if there's an emergency and the pilots decide to divert they will often dump fuel (if possible) or simply fly in circles to burn off enough to bring the airplane down to a safe landing weight. Safety isn't just a matter of preventing the landing gear from collapsing. A higher weight means a higher landing speed due to stall limits and thus a longer stopping distance and greater risk of brake failure or runway overrun.

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

#24

Post by jcoffland »

saosebastiao wrote: post #22
jcoffland wrote: post #20

Earlier quoted context omitted.

You could swap batteries.

That does seem to be the current model for fast recharges. It's not out of the question, but these are going to be extremely big batteries and the planes, batteries, and auxiliary equipment need to be designed for it up front. The thing with planes is that design is extremely expensive and design costs are expected to be amortized over a long lifecycle, which means that a technical constraint today could end up being…

You are right. Weight distribution would be an important factor so you cannot just swap out a big block of battery on one end of the plane. Perhaps a long tube running down the plane. You push charged batteries in one end and pull discharged ones out the other. The track they run on connects them to the electrical system.

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

#25

Post by ryanwaggoner »

Aviation as a field is littered with dozens (hundreds?) of startups that have blown through millions and decades trying to build certified aircraft and going bankrupt in the process.

Not the first to say this, but there is zero chance that this startup designs and builds a certified electric airliner in the next decade. I highly doubt we'll have these in 20 years. In ten years, we might have battery technology where it starts to make sense, but the most experienced builders of large aircraft in the world generally spend at least a decade and billions of dollars developing new planes. And this will be with completely untested technologies, new safety procedures, engines, etc. Boeing spent $32 billion bringing the 787 to market. On the smaller end, Bombardier spent ~$5 billion on the C series, which looks comparable to this, and I'd expect costs on this to be MUCH higher since it's a lot of new and untested tech, instead of iterating on decades of prior experience.

This is either appallingly naive on the part of this team and / or their investors, or this is an acquisition play. I doubt the latter makes sense, and I wonder if this is just VCs not having any knowledge of the field or how unrealistic this is.

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

#26

Post by logicallee »

nradov wrote: post #23
logicallee wrote: post #21

Earlier quoted context omitted.

This doesn't pass the smell test for me. The vertical velocity when it lands it not very great - if landing gear has no trouble supporting the plane during taxi off under full weight, I find it preposterous (and reckless) that it would be insufficient for landing. The idea that planes routinely dump fuel if they have to circle around and land immediately after take-off is absolutely ridiculous to me: if there is noth…

You're not seeing the whole picture. Airliners don't routinely dump fuel during normal operations. However, if there's an emergency and the pilots decide to divert they will often dump fuel (if possible) or simply fly in circles to burn off enough to bring the airplane down to a safe landing weight. Safety isn't just a matter of preventing the landing gear from collapsing. A higher weight means a higher landing speed…

But we're not actually talking about emergencies here at all, but rather "by-design" in which nothing is wrong. And a future design at that!

I hope you can see why I am skeptical that a future landing gear for electric airplanes would not be able to support the fully loaded landing weight, which is not reduced as the batteries are depleted.

The idea that landing gears just "can't" support all that weight seems silly to me. The solution can be as simple as having twelve wheels instead of six, or another set of shock absorbers, or something short of "well sorry, you'll never build a landing gear that lands safely at that weight. Can't be done."

Note that I focused on just the weight the landing gears support - your other observations can remain on-point. I just don't buy that particular argument, just about the landing gears.

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

#27

Post by dexterdog »

logicallee wrote: post #26
nradov wrote: post #23

Earlier quoted context omitted.

You're not seeing the whole picture. Airliners don't routinely dump fuel during normal operations. However, if there's an emergency and the pilots decide to divert they will often dump fuel (if possible) or simply fly in circles to burn off enough to bring the airplane down to a safe landing weight. Safety isn't just a matter of preventing the landing gear from collapsing. A higher weight means a higher landing speed…

But we're not actually talking about emergencies here at all, but rather "by-design" in which nothing is wrong. And a future design at that! I hope you can see why I am skeptical that a future landing gear for electric airplanes would not be able to support the fully loaded landing weight, which is not reduced as the batteries are depleted. The idea that landing gears just "can't" support all that weight seems silly…

I was specifically talking about an emergency situation. Planes don't do early landings when nothing is wrong.
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