I Sing the Airplane Electric
flyingmag.com
flyingmag.com
Apparently, the entire setup is doable for less than $40K. Given the right circumstances (like, an airport at both ends and living in a place with generally nice, warm weather), it could be a fantastic tool for an affordable, fast commute.
Here's another story by Gabriel about completing a 100-mile journey: http://inspire.eaa.org/2020/01/09/99-miles-on-batteries/ (with recharging stops).
It looks like the maximum range of his setup is 60-miles, but with what he considers a "safe" amount of margin, he limits his trips to 40.
I understand the attraction to owning your own plane and buzzing merrily above the wheel-bound masses below on the daily, but I have to think it's a bad idea (avgas or electric). I think of all the times I've overslept, needed to be at the office unexpectedly, forgot to put some air in the car tires, should get that warning light looked at, etc... phrases that are usually at the start of an NTSB report.
The beauty of airlines and charters is that you're paying them, at least in part, to tell you "no, we're not flying right now." Turns out it can be hard to do for yourself when your job depends on it.
Small electric planes with lower per-hour operating costs are also a game-changer for flight schools and their students. Cheaper pilot licenses should translate into increased supply of qualified labor and lower the costs of starting/operating an airline.
How similar are EV airplanes and ICE powered ones? Aren't there a number of factors that vary from motive power and availability to weight/form factor that make training on an EV not sufficient to training on "the real thing"?
> I think the grand idea is that with improvements to battery density and weight this will spill into commercial aviation market.
That's a pipe dream for 2 reasons:
1) battery density is still a small fraction of fuels
2) thus small trainers are about the weight limit you'll see for electric aircraft. There is no path for airliners to propel with batteries.
3) Most of the small electric airplanes have been destroyed in battery fires. So aviation-grade batteries will be needed, and anything certified will be very expensive.
> Small electric planes with lower per-hour operating costs are also a game-changer for flight schools and their students.
"lower per-hour operating costs" would be nice, but fuel is not the dominant cost for flight training, and is not a game changer. In addition, most of the small electric planes you have read about were destroyed in battery fires, killing the pilots.
> Cheaper pilot licenses should translate into increased supply of qualified labor and lower the costs of starting/operating an airline.
No, you're not going to see cheaper pilot licenses (unless you personally open some kind of flight school as a charity), and in the US, the 1,500 hour rule means operating an airline will be expensive. Almost all of the US "regionals" have already shutdown due to a shortage of ATP holders.
It gets old reading aviation news on HN because the fanbois can't separate SciFi from reality. Aviation is an expensive, regulated industry, and will only become more that way.
So let me explain what the game changers are ...
For amateur non-IFR practise and commuting, combining a Sport Pilot or Private Pilot license ($10,000+) with an electric LSA (under 1,320 pounds) plane and free tie-down would be a game-changer for non-commercial use.
(There's no affordable airport access in the Bay Area since tie-downs start at $500/month, and hangars at $1,000/month. No municipality will let you "take off and land" on your driveway in any urban area.)
Otherwise, you're looking at ultralights (under 254 pounds), which is not what most people consider a safe way to commute, but you could trailer. There is one all-metal ultralight, the Hummel, that looks like an airplane, so it is possible to build one for ICE. (See below why that doesn't include electric.)
https://flyhummel.com/ultra-cruiser/
Note that ultralight weights don't include fuel or pax, so it's that weight plus fuel. (LSAs gross weight is 1320 pounds, so that includes fuel and pax.) However, batteries would subtract from the empty weight, making those categories useless!
https://en.wikipedia.org/wiki/Light-sport_aircraft
What I described above is non-experimental US aviation. If you're clever, there are workarounds using experimental aircraft that can help with the weight limits. However, you can't do any commercial activities, and insurance may not be available for carrying passengers.
So instead of the SciFi nonsense, please follow the above to create a reality-based plan, instead of "Gee-whiz, I can't wait for electric airliners!"
In other words you should always be willing(and able) to cancel a flight under any circumstances or areas of caution.
Checklists are key, but the pilot must be willing & able to take appropriate action when a checklist item fails or cannot be completed -- i.e., stand down & cancel, instead of "it should be fine...".
That failure to cancel is two of the three items usually needed for a crash (the failure itself and the bad pilot decision).
Ok, going 40mi you have only so much weather than can go wrong, but I've had friends trapped at an airport due to weather, leave their plane and drive/fly commercial home. It's a fun hobby though. :D
It's definitely not practical for most but it would be great. And not having much of a precheck would be really nice.
> Taking the preliminary 2013 fatality rate in general aviation of 1.05 fatalities for every 100,000 hours of flight time and scaling it up to 2 million hours gives a comparison rate of 21 general aviation fatalities per every 2 million hours. This suggests that stepping on a private plane is about 19 times more dangerous than getting into the family sedan.
[1]: https://www.livescience.com/49701-private-planes-safety.html
You also get more options for blade types. Like ducted fans.
In short, your plane doesn't have to be designed around a fat gasoline engine and tanks. There's still constraints, but you get much more creative freedom.
I expect when we see planes designed around the motor/batteries we'll see aerodynamics get electric planes into GA territory.
EDIT: aerodynamic efficiencies. [1] Yes there's that tractor/pusher Cessna, no one liked it.
You can package things however you want, even in weird shapes. Not "has to allow liquid to flow downhill, even in rate 2 turn". I'll bet there's still wins to be found even with putting batteries in wings.
This is true for Bye's eflyers, the Eviation Alice, the Pipistrel models, etc. These have modest but usable ranges (currently advertised) and are far enough in the development process that they might hit the market in some modest numbers in the next few years. But that's with battery technology of basically a few years ago. There's obvious room for improvement by simply updating the battery technology. 2-3x over the next decade is not an unreasonable expectation; the biggest hurdle is certification.
The real thing to look for with electrical planes is range & operational cost. Yes it's annoying to not be able to fly 5 ours straight. But 2 hours is still pretty good. This would require doubling the power/kg for this plane, which sounds like it should be feasible; if not now than maybe in a few years. Also, turning a 100$ hamburger into a 5$ latte flight is going to be quite literally be the difference between being able afford to fly or not at all for a lot of people. GA flight is a really expensive hobby currently.
I think what will happen is the experimental market exploding pretty soon. There's a critical mass of technology coming on the market and it's going to be very tempting for people to start building kit planes they can actually afford to fly. There are some fine examples of some daredevils on youtube flying some DYI contraptions already.
http://thundergull.com/specifications.htm
It's got 95sqft of wing and a top speed of 63mph. Drag is usually with velocity squared so going 1/2 as fast might only require 1/4 as much power.
They state in the article that it takes 10kw to fly level. With 100sqft and an average 10W/sqft you're at 1kw. But cut the speed down to 30mph (2500W) and double the wing area (2000W) and you're very nearly at breakeven. The 11kw battery might then last you 10+ hours after accounting for the power required to climb out.
Yes it'll end up being much more of a power glider than a "proper" airplane but that might be a lot of fun.
Or ~40MPH (2/3 the speed) and double the wing size.
Turns out that this is a thing: https://www.solar-flight.com/
Yes, changing types will require some training, but it's a big savings if you can get your PPL in a plane with an operating cost of $1/hour. If you look at vendors that are selling production electric aircraft, they claim 70% savings on training operations. That's a big deal. (Link: https://www.pipistrel-aircraft.com/aircraft/electric-flight/...)
Learning to fly at its most basic is much more than just stick-and-rudder skills. There is a lot of information to learn, procedures, airspace, radio work, etc.
It's best to learn how to fly in the simplest safe aircraft possible. Then when you have to learn to operated a very complicated machine you don't even have to think about the flying part.
Complex aircraft are also much more expensive per flight hour, so it makes sense to learn on the cheapest safe thing you can fly then let your employer foot the bill for the type rating.
Also, one specificity of ultralight flying, or at least the way I was taught, is to not trust the engine, no matter how reliable it is supposed to be. One aspect is to make the final approach unpowered. Of course, the engine is still running, but ideally, you should pull the throttle all the way back and leave it here, as if the engine had failed. This is in contrast to the 3° slope commonly taught in general aviation.
Of course, a pilot who only flew on an electric plane needs some time with a flight instructor in order to learn the quirks of gas engines, but that should be quick compared to the time it takes to actually learn how to fly.
Of course nobody's going to be commuting in a sailplane, but they're awesome for pure fun and learning piloting skills.
They're optimized for energy efficiency? Yes? What does this gotcha response even mean?
For plane designed from ground up as electric fact that jets land lighter than take off is not relevant.
It is only relevant if you want to retrofit electric engine on jet engine optimized chassis - which is not only possible way.
Bit more info on how thought process goes: https://spectrum.ieee.org/aerospace/aviation/how-i-designed-...
These are constraints that can be designed around, and you have more freedom to do so when designing from scratch, but doing so is not a optimization, it is a straightforward trade-off between weight and duration. There's no optimal hump on that line.
Hydrogen has a specific energy of 120 MJ/kg, while Kerosine has 46 MJ/kg. According to the abstract of the paper being discussed here, the new material has a deliverable capacity of 14% by weight, corresponding to about 17 MJ/kg - only a bit better than 1/3 that of kerosine, but considerably better than lithium ion batteries, which apparently achieve less than 1 MJ/kg, while the best-performing lithium-sulfur batteries are at about 1.8 MJ/kg.
In addition, we must deal with this material only losing 14% of its weight as its hydrogen is used up, while kerosine loses all of its weight - a combustion-powered airplane becomes more efficient as its fuel is consumed.
Furthermore, to get that 14% deliverable capacity, you have to start with it at 100 bar, so the tank containing it will have a substantial weight.
So we have progress here, but not yet a substitute for liquid hydrocarbons.
Between the fuel and the cells, batteries are just so much easier to operate once they're out in the field, there's no comparison.
Also, Li-S still has too low of energy density for airplanes, and given the long recharge time problem batteries fundamentally are a no-go in aviation.
Recharging time isn't an issue, just have the batteries swappable.
I'm particularly curious about how this would work with a hybrid glider or other aircraft with long glide paths where you could use the electric to get up to elevation and glide the rest of the flight.
I think you might see rentals come from $155/hr to $125/hr. I doubt you'd see them go under $100/hr, and I'm not sure that's enough of a difference to drive a material increase in student traffic or affordability.
Believe me, I wish it would. I started flying almost 25 years ago and it was much nicer when the airports were busy and when trade professionals (plumbers and electricians) could afford to fly. Now, I mostly see doctors and tech people at the airport as new student starts and that's not enough to really sustain vibrant airport businesses.
Engine overhauls every X,XXX hours was another, but I'm not sure if you need an engine overhaul on an electric plane. How does battery replacement stack up against fuel tank replacement/ leaks? This is all up in the air, but based on the difference in ICE car maintenance versus electric, I'm pretty optimistic that there will be more savings than just the actual fuel costs.
But even you ignore other potential savings, just fuel savings alone drops prices by 35% using your numbers which is a pretty big savings.
That's why people talk about the 100$ hamburger. Because if you add it all up that's what you are spending per hour roughly.
With electric, you fly way cheaper than that because the components are cheaper, more durable, and way fewer in number and there is just a lot less that goes wrong with these planes. That and the fact that electricity is dirt cheap. This ultra light sounds like a pretty cheap thing to fly.
Times have changed.
The founder (a fighter pilot) originally built a civilian fighter jet with Israel Aerospace Industries years ago. He also built an advanced solar electric UAV which DARPA is using to "ambitiously" try to recharge drones with a laser.
The commercial version of this should probably "idle" the propellers at 30 RPM or something... fast enough to notice, without burning much power.
Battery energy density is very less, but having a constant speed small, optimised IC engine to generate electricity from fuel could increase range and capacity of these planes.
So if you have to keep it, you're trading a bit of efficiency for a lot of complexity.
(outline of a launch: aircraft and tug are connected by cable before launch, both lift-off, gain altitude, cable is detached, aircraft moves on and tug returns to launch site)
[0] https://www.lilium.com [1] https://en.wikipedia.org/wiki/Lilium_Jet