NASA Partners With General Electric To Advance The Future Of Electric Flight (zdnet.com) 79
"Electric flight is becoming a tantalizingly close reality for shorter-range service," writes ZDNet. "But increasing passenger carrying capacity and flight times to economically accommodate longer routes will require a major rethink of crucial components."
pgmrdlm quotes their report: GE is partnering with the NASA Advanced Air Vehicles Program on a new generation of inverter using GE's silicon Carbide technology. The project aims to deliver a next gen inverter that provides significantly increased power density over existing technology but is small enough to support electric flight."We're essentially packing 1 MW of power into the size of a compact suitcase that will convert enough electric power to enable hybrid-electric propulsion architectures for commercial airplanes,"says Konrad Weeber, Chief Engineer of Electric Power at GE Research. "We have successfully built and demonstrated inverters at ground level that meet the power, size and efficiency requirements of electric flight. The next step is to build and demonstrate one that is altitude ready...."
GE makes an ideal development partner for NASA because it's a vertically-integrated, one stop shop. GE designs everything from chips to system level architecture, which makes optimizing a final design to conserve space and weight much more practical over cobbling together a system from multiple contractors.
pgmrdlm quotes their report: GE is partnering with the NASA Advanced Air Vehicles Program on a new generation of inverter using GE's silicon Carbide technology. The project aims to deliver a next gen inverter that provides significantly increased power density over existing technology but is small enough to support electric flight."We're essentially packing 1 MW of power into the size of a compact suitcase that will convert enough electric power to enable hybrid-electric propulsion architectures for commercial airplanes,"says Konrad Weeber, Chief Engineer of Electric Power at GE Research. "We have successfully built and demonstrated inverters at ground level that meet the power, size and efficiency requirements of electric flight. The next step is to build and demonstrate one that is altitude ready...."
GE makes an ideal development partner for NASA because it's a vertically-integrated, one stop shop. GE designs everything from chips to system level architecture, which makes optimizing a final design to conserve space and weight much more practical over cobbling together a system from multiple contractors.
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Like a buddy of likes to say, you can't spell garbage without GE.
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When was the last time you flew on a commercial airliner? Did it have GE Aviation jet engines on it?
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21 years ago, and I was the one doing the flying (yay flight school.) It had Rolls Royce turbines.
When was the last time you touched actual airplane controls?
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For me, that would be yesterday. Beechcraft Bonanza. V Tail.
I don't trust them in Aerospace. (Score:2)
Ethiopian Airlines went into the ground exactly 11 days after GE Aerospace fired me for being a boyscout and going "WHAT THE FUCK" on the project I was hired for. I have shared every single article about the MAX8 with her and other friends I've vented to with a "Yeah, exactly this but at GE and slightly worse because it was military". I'm feeling slightly vindicated.
But don't worry it was for a military project and "if it kills someone, that's what they signed up for". (Literal quote from someone on my firs
Electric airplanes and wind (Score:1, Troll)
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Why all this fuss about special technology? It's already on the air, they should just use wind power.
say again?
Re: Electric airplanes and wind (Score:1, Troll)
Speed? (Score:2)
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It is not just battery weight that is a problem. Right now, we are not even allowed to bring E-bike batteries on passenger airplanes. How far away from flight qualified whole-aircraft battery packs are we? I would guess at least 5 years. Maybe 20 years. Maybe never.
I can't see how jets can ever be replaced, nor jet fuel, for long-distance flights. Especially over oceans, where building rail infrastructure is impossible. We could maybe learn to make jet fuel from CO2 in the atmosphere using solar electricity
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There is a direct connection between weight and hazard.
See also "energy density".
As long as long, energy dense carbon chains in the form of gasoline are safer than energy stored in batteries...
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Even if electric aircraft are never good enough for long-distance flights, they could still be decarbonized via biofuel or electrofuel.
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16 years ago the Lange Antares 20E was flight certified with a 42kWh lithium battery.
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The Douglas DC-7 had a cruising speed of 580kph (360mph) whereas a Boeing 737 has a cruising speed around 900kph. Even assuming that a modern design will be a bit faster than an aircraft designed in the 1950s it seems likely that electric powered aircraft will be a bit slower than we're used to. Not a big deal I think even on transcontinental or transatlantic flights. Transpacific and other really long flights would presumably be even more tedious than they are now.
Caveat1: I'm in no way, shape or form
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Caveat2: I'm a bit dubious about battery energy density(technically "specific energy"?). IIRC, Lithium-ion batteries are not all that far from their theoretical energy density limits. And Current Li-ion batteries are pretty heavy. That's why a Tesla Model3 weighs more than a Toyota Camry despite the latter lugging around a fairly massive ICE and transmission. I'm told that on paper, some battery chemistries -- especially those that use atmospheric Oxygen as one of the reactants -- can approach fossil fuel energy densities. But I'm pretty sure that we can't build them today even in the laboratory and there's no guarantee that fossil fuel energy density batteries won't come with fossil fuel explosion potential or other drawbacks.
The situation is actually worse than that. Not only is the battery heavy so diminishing returns are quickly reached as the aircraft becomes larger, but the battery weight is constant while fuel is burned lightening the aircraft as it travels considerably extending its range. The total weight of fuel cannot even be replaced with a battery because large aircraft cannot land safely with a full load of fuel and cargo; they have provisions to dump fuel if it becomes necessary.
Megawatt Inverter? (Score:2)
Maybe I'm missing something, but why do they need a megawatt inverter when the weight of batteries a plane could conceivably carry would be in the sub megawatt-hour range?
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100 kW is not enough power to take off unless the plane is small (like 4 passengers or something). So if you can't be in the MW range, might as well forget it. Cruise will need less power. Take-off is where the peak power delivery needs to occur.
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100 kW is not enough power to take off unless the plane is small (like 4 passengers or something). So if you can't be in the MW range, might as well forget it. Cruise will need less power. Take-off is where the peak power delivery needs to occur.
"We're essentially packing 1 MW of power into the size of a compact suitcase"
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Yeah. I guess I should have quoted the parent. In my mind here is how the conversation went:
why do they need a megawatt inverter?
100 kW is not enough power to take off unless the plane is small (like 4 passengers or something). So if you can't be in the MW range, might as well forget it.
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Why don't they just use inductive power delivery?
I Qi'd! I Qi'd!
Okay, I'll see myself out.
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For reference the original Nissan Leaf had an 80kW motor.
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So let's use MLAs to get planes up to takeoff speed. You could even tow them aloft, then land the tow plane at another airport to recharge.
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Automotive-style li-ion batteries start at around 1kW/kg and go up from there. Power is not a problem. Energy is the limiting factor, which limits electric airplanes to regional transport at present.
As for the article: silicon carbide MOSFETs seem to be the future. The old Model S and Model X (before the Raven update) used IGBTs, but the new Tesla powertrain uses SiC MOSFETs.
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You are not getting Rei's point. Batteries have both a POWER DENSITY and an ENERGY DENSITY. From Rei's answer, Rei clearly understands both. You, on the other hand are comparing Rei's power density specification to energy density of current batteries. In actual fact, high power density is not needed in battery packs that drain slowly. But high power density is very important in small EV battery packs and power tools and vapes and such. Because very high power is needed. The cells designed for highest energ
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Teslas have about 1kW/kg at the pack level, higher at the cell level. Jack Rickard measured Model 3 cells at 247Wh/kg. Factory Mode reports the full pack energy at 76kWh, and thus the cell contribution to pack mass is 307kg (not to be confused with the full pack mass, which is 480kg). Factory Mode lists the hardcoded max power output at 370kW (which corresponds well to the max power output of the motors in Model 3 Performance). But it also lists max discharge current at 1200A and max brick voltage at 409
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Ed: Forget that first line, I wrote that wrong.
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I believe that when I see an electric locomotive using them instead of IGBT. Railroad always has been the early adopter of promising electric tech.
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Maybe I'm missing something, but why do they need a megawatt inverter when the weight of batteries a plane could conceivably carry would be in the sub megawatt-hour range?
RTFA?
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I doubt the inverter is limited only to induction motors. The control algorithm is different for BLDC (or PMAC) and induction motors. But the power switching architecture is exactly the same and the power loss in the inverter is the same (only depends on motor current). Any extra power loss in an induction motor would be inside the induction motor, not the inverter.
Switched reluctance motors can be driven with fewer switching elements, but they are also compatible with the switching architecture used for in
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GE is bragging about the benefits of the Si Carbide switching devices more so than any finished product. You are kind of missing the point.
No, I have not missed the point. Silicon Carbide MOSFETs have three main advantages. 1: somewhat Higher voltage (1200V vs 1000V). Useful, but would be equally useful for PM or reluctance motor. 2:somewhat lower on resistance. same as for number 1. 3: much higher switching speed. This is only valuable for applications that require very high switching speed, such as AC induction motors. Even with this advantage, the reluctance motors are still superior. So much so that a "standard" reluctance motor using regular silicon MOSFETs is going to have better efficiency than an AC induction motor and controller using SiC MOSFETs. GE as usual, is hyper focused on the wrong thing, or at the very least has ignored important parts of the overall design. Using their new SiC MOSFETs, a power controller for a reluctance motor will be significantly smaller and more efficient than the equivalent power controller for the equivalent AC induction motor.
You want this to be about the motor type. But it is not. It is about the type of semiconductor being used to control the motor. Silicon Carbide can run at much higher temperatures than IGBT's or MOSFET's. This is a big advantage all by itself. But ultimately, the whole article is just a press release put out by GE to tout their Si Carbide switching devices. I don't attach much importance to it.
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The significance of SiC or GaN power transistors versus silicon ones is the gain in power density that higher voltages, higher currents, higher efficiency, and faster switching speeds allow.
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But the power switching architecture is exactly the same and the power loss in the inverter is the same (only depends on motor current)
That is absolutely incorrect. It is a common misconception, but a misconception nonetheless. An AC induction motor must have a power controller that switches many times per pole in order to generate a reasonably accurate AC waveform. This is 100% necessary because the AC sine wave is what transforms power into the rotor. If the waveform is imperfect, then the efficiency of the motor drops as it induces parasitic current loops in strange places. This effectively means that the switching frequency must be in the 500k to 1M range, and as such will suffer relatively high switching loses. A reluctance motor only needs to switch twice per pole, and as such can typically operate in the 10k to 50k range, cutting the switching loses by 90% or more. That is why Tesla has switched to a hybrid PM / reluctance motor design for the model 3, and is likely to do the same for the roadster. It makes the motor and controller smaller and more efficient, meaning you can push far more power through them for the same amount of cooling.
I am not sure where you are getting your information. But typical switching frequencies for control of brushless DC and induction motors are from 5kHz up to maybe 20 kHz. There is not much reason to go any faster than that in most applications. I suppose that if you had a high pole-count motor and you needed to spin it very fast, you might need to up the PWM frequency. But that is a specialized application. This is stuff that I work with regularly.
I admit I am not an expert on reluctance motors, but you you
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How you come to 500k to 1M is beyond me when a normal car has a motor that rotates with about 6000 rpm max.
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Pouch cells offer lower weight and cost so aircraft would likely want to use those. The lack of a metal housing and ability to pack them more densely is a big advantage.
Tesla is more focused on high performance batteries so are sticking with cylindrical cells, but for lower cost and weight pouch cells are the way forward.
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Maybe I'm missing something, but why do they need a megawatt inverter when the weight of batteries a plane could conceivably carry would be in the sub megawatt-hour range?
The summary stated this was for electric hybrid aircraft, they do not intend to fly the airplane with battery power alone. With that in mind consider the use cases.
One such case, an aircraft with a typical kerosene burner engine under each wing and an electric center line "booster" propeller for take-off and other critical stages of flight. The battery, or other electrical storage, only needs to store enough energy for managing a single engine loss on takeoff. Maybe there isn't any electrical storage for
Flight - electric or not, who cares? (Score:2)
Human's ability to fly, not as a special occasion, but on a regular basis — like to work and back — is long overdue. It does not need to be electric — gasoline, kerosene, diesel, alcohol — whatever works.
Re: Flight - electric or not, who cares? (Score:2)
I dont believe we canâ(TM)t work out the safety problems with hydrogen. Hydrogen has greater energy density than jet fuel, powers the strongest rockets, and could work in jet engines, if it could be stabilized somehow.
https://www.nasa.gov/topics/te... [nasa.gov]
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I dont believe we canâ(TM)t work out the safety problems with hydrogen. Hydrogen has greater energy density than jet fuel, powers the strongest rockets, and could work in jet engines, if it could be stabilized somehow.
https://www.nasa.gov/topics/te... [nasa.gov]
This too
https://newatlas.com/nasa-chee... [newatlas.com]
Comment removed (Score:5, Informative)
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Specific energy, not energy density.
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The electrolysis method of hydrogen production has a phenomenally bad efficiency. ...
It is about 70% efficient.
Considering that burning fuel in an ICE is only ~20% efficient, that is pretty good
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if it could be stabilized somehow.
You mean like by attaching a carbon to every 4 hydrogens? That sort of thing could work. ;)
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Hydrogen does not have a higher energy density than jet fuel.
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Hydrogen does not have more joules per kg than kerosene? I don't think that can be right. I am pretty sure that reacting hydrogen with oxygen is the most energetic reaction you can reasonably have (unless you are willing to build a hydrogen/fluorine rocket).
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"Human's ability to fly, not as a special occasion, but on a regular basis — like to work and back — is long overdue."
Patience grasshopper. If we gave average humans flying cars, no structure or living entity on the surface of the planet would be safe. Before you can have your flying car, "they" have to solve all the problems of navigating autonomous cars. Then they have to solve them again along with a few additional problems in three dimensions. And we'd probably need a new -- much enhance
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"Human's ability to fly, not as a special occasion, but on a regular basis — like to work and back — is long overdue."
Patience grasshopper. If we gave average humans flying cars, no structure or living entity on the surface of the planet would be safe. Before you can have your flying car, "they" have to solve all the problems of navigating autonomous cars. Then they have to solve them again along with a few additional problems in three dimensions. And we'd probably need a new -- much enhanced -- Air Traffic Control infrastructure. Not impossible. But it'll probably take a few decades, ... at least.
If you bought a flying vehicle today that could take off and land in your driveway and at your job, it'd cost a fortune, would require a pilot's license, the cost of the insurance policy would be eye watering, and you wouldn't be allowed to fly it anywhere near critical infrastructure -- which would effectively ground most us. A nifty inverter isn't going to solve any of those problems.
They are talking about commercial flights. Somewhere in between taking off from your driveway, and the ordeal that is going to the airport.
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Oh, wow, thank you for condescending to explain... Just who are these omniscient benevolent you, who cannot give the unwashed us the flying cars for our own good?
Ah, so you have the actual chassis, the engine, the fuel all figured out — just waiting for the autonomous part to work? Why, then, are you wasting your time with the autonomous surface vehicles? Making a regular car drive itself — on the imperfect road
What will be the power source? (Score:3)
We are tantalizingly close to electric flight as long as we don't need large, flight-qualified lithium ion (or polymer) batteries.
Considering the increasingly strict rules about lithium ion (or polymer) batteries on commercial flights, it seems rather unlikely that we can have 1 MWh lithium ion (or polymer) batteries any time soon that are flight qualified and light enough.
But electric motors may still have advantages, even if the electricity comes from a combination of a fuel-burning generator and a small, high-power-density battery pack.
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There seems to be a fundamental failure to understand energy density amongst the general public.
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There seems to be a fundamental failure to understand energy density amongst the general public.
That may be, but his points are still valid.
As for energy density, yes, it's a real-world limitation determined by physics, but we haven't gotten anywhere near the limit of battery technology.
The whole idea of flight itself was ridiculed until technology advanced far enough to make it a reality.
Flying? It was absurd notion! You might as wish you could somehow go up a hill at 50 miles per hour!
And yet now we routinely fly wherever we want and drive up hills at 50mph without a second thought.
I think electric
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/crotchety old man voice : "If man were meant to fly god would have given him wings!"
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But electric motors may still have advantages, even if the electricity comes from a combination of a fuel-burning generator and a small, high-power-density battery pack.
I have always thought this was an interesting hybrid solution.
You can get a gas engine to generate a LOT of current if that's all it's doing, that is, if it's only turning a generator and not being used to directly move a vehicle or perform some other physical task.
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We are tantalizingly close to electric flight as long as we don't need large, flight-qualified lithium ion (or polymer) batteries.
Considering the increasingly strict rules about lithium ion (or polymer) batteries on commercial flights, it seems rather unlikely that we can have 1 MWh lithium ion (or polymer) batteries any time soon that are flight qualified and light enough.
But electric motors may still have advantages, even if the electricity comes from a combination of a fuel-burning generator and a small, high-power-density battery pack.
Let me just preface this by saying "this is real" :
https://xnrgi.com/ [xnrgi.com]
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This may be the use case for fuel cells.
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Jet
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Fossil aircraft have wings full of flammable liquid and their engines are powered by explosions.
Flight qualification for aircraft batteries won't be a problem. The issue with passenger's lithium batteries are that they are not tested to any rigorous standard often not designed with any kind of fire safety in mind. Oh, and paranoia about terrorism of course.
Sounds very interesting (Score:3)
I think there's definitely a future in electrically-powered flight. There are tremendous advantages if it can be done.
Refueling costs drop to almost nothing compared to using jet fuel. All of the infrastructure needed for handling a highly volatile liquid fuel goes away, along with all the attendant safety issues.
Electric motors are much, much simpler than internal combustion (IC) engines or commercially-used jet engines. Very little maintenance is required for an electric motor, and the maintenance costs are far less.
They're also much less prone to failure, including catastrophic failure. As for length-of-service, it's no problem to run a quality electric motor 24/7 for years nonstop. I don't know of any IC engine that can do that.
Electric motors require almost no warm-up period, lubrication is dead simple, and cooling is simpler as well.
Economy of operation is far better than gas or jet engine in both the short- and long-term.
Vibration and noise are almost nonexistent in electric motors compared to gas or jet engines.
Electric motors have damn near every advantage over internal combustion engines except for power. Pound for pound, internal combustion engines have the clear advantage there (at least for now).
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https://newatlas.com/nasa-chee... [newatlas.com]
The Most Awesome Taser! (Score:1)
."We're essentially packing 1 MW of power into the size of a compact suitcase that will convert enough electric power to enable hybrid-electric propulsion architectures for commercial airplanes,"says Konrad Weeber, Chief Engineer of Electric Power at GE Research.y
Now if you could hook that suitcase into a Taser, I want one.
Excellent for walking around and zapping random folks.
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Now if you could hook that suitcase into a Taser, I want one.
Excellent for walking around and zapping random folks.
If you hit a person with 1MW of power they'll pretty much disappear into a carbonized cloud of dust.
Actually, now that I think of it, that would be a pretty handy gadget to have.
This is just a press release from GE (Score:2)
This isn't really a news story per-se. This is just a general electric press release that ZD net picked up and published as a story. That is a standard journalistic practice. They call it "re-writing" the press release, even though they don't always do much re-writing and just publish it almost verbatim.
The press release is always written in a news story format to facilitate the process of publication.
Here is the original press release:
https://www.ge.com/research/ne... [ge.com]
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This isn't really a news story per-se. This is just a general electric press release that ZD net picked up and published as a story. That is a standard journalistic practice. They call it "re-writing" the press release, even though they don't always do much re-writing and just publish it almost verbatim.
The press release is always written in a news story format to facilitate the process of publication.
Here is the original press release:
https://www.ge.com/research/ne... [ge.com]
The definition of news.
Question (Score:2)
Genuinely curious here.
That 1MW table-top inverter they are talking about. What kind of efficiency specification do they have to meet and what can they achieve?
It wouldn't take much percentage to melt everything down. There is only so much heat you can pump out of a device that size.
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One of the properties of silicon carbide is that it can operate at very high temperatures. However, yeah, for sure, they need to deal with cooling. Even 1% power loss in the inverter is 10kW of power that has to be dissipated as heat. Doing that in something the size of a suitcase will be difficult without liquid cooling.
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Hope they plan on redundant cooling. Or one inverter per "engine" at least. Some shitty cooling pump part breaks and all the engines stop.
Or GE could partner with (Score:1)
Or GE could partner with an aircraft firm, or even with itself, and leave the taxpayer out of it.
A radical concept, it's true.