From the “ultimate range anxiety” department.
NEW YORK (Reuters) – A Seattle-area startup, backed by the venture capital arms of Boeing Co (BA.N) and JetBlue Airways Corp (JBLU.O) announced plans on Thursday to bring a small hybrid-electric commuter aircraft to market by 2022.
The small airliner is the first of several planes planned by Zunum Aero, which said it would seat up to 12 passengers and be powered by two electric motors, dramatically reducing the travel time and cost of trips under 1,000 miles (1,600 km).
Zunum’s plans and timetable underscore a rush to develop small electric aircraft based on rapidly evolving battery technology and artificial intelligence systems that avoid obstacles on a road or in the sky.
In a separate but related development, Boeing said on Thursday it plans to acquire a company that specializes in electric and autonomous flight to help its own efforts to develop such aircraft.
Several companies, including Uber Technologies Inc [UBER.UL] and European planemaker Airbus (AIR.PA), are working on electric-powered self-flying cars.
Zunum does not expect to be the first to certify an electric-powered aircraft with regulators. Rather, it is aiming to fill a market gap for regional travel by airlines, where private jets and commercial jetliners are too costly for many to use.
…
Electric-vehicle batteries, such as those made by Tesla Inc (TSLA.O) and Panasonic Corp (6752.T), would power Zunum’s motors, although Zunum has no commitment with either company. A supplemental jet-fuel engine and electrical generator would be used to give the plane a range of 700 miles and ensure it stays aloft after the batteries are exhausted, Knapp said
…
Current battery technology can only power the plane for about 100 miles so a gas-powered engine would be used to generate electricity to power the motors for additional range.
Full story here.
Once again, fossil fuel power is used for reliable power. Dr. Roy Spencer quipped on his Facebook page:
I’ll bet they won’t even be able take off on battery power alone… and why would you use a gas powered engine to charge the batteries in-flight? I’ll bet the efficiency of that is way below a jet engine burning the fuel directly.
Looks like this is more for publicity show than anything else, we’ll see if it actually works or if the fleet will end up in the hangar most of the time like the much ballyhooed LAPD electric police cars that sit mostly idle.
Interestingly, and suggesting low confidence in the project, neither Boeing nor Jet Blue has anything about this electric plane on their press release sections of their websites here and here.
Bullshit!
Why?
Gets my vote for most astonishment-charged expressive momosyllable of the year so far and sets a very high bar to clear. Gratters Bob.
We have a saying about these sorts of projects in the aerospace industry:
“A bad idea whose time has come.”
From an energy usage position this confuses me. For aircraft, weight is paramount. The weight fraction between vehicle and what ever you are transporting (payload) is held very tightly for efficiency. Adding merely yet another energy conversion seems ill-considered. The chemical energy from the fuel is first converted to mechanical energy via combustion. This is where most jet propulsion gets it thrust, form the by-pass turbines and expansion of the heated air. Most aircraft stop here as they are already working. This Rube-Goldberg of an idea simply adds 2 more middle man steps. It takes the energy used for thrust and converts it to electrical energy (via turbine?) which must then convert it back into mechanical energy via an electric motor which then provides thrust and propulsion for the aircraft. So all they have managed to accomplish is to add the unnecessary weight of batteries and electric motors while reducing the overall energy usage efficiency. “It may be more inefficient, but it is heavier.”
Where did these fools study engineering? What was their source textbook, “Popular Mechanics”?
They could completely Rube it out and place stationary bicycles in the passenger cabin so they can peddle their way to generating electricity
extension cords are not that long!!!!!
hey rocketscientist, butt butt butt, isn’t some one gonna invent a supper dupper capacitor or some thing???
This was my first thought as I read this, why add another power loss to the equation?
Passengers would definitely have to help with power production, better than the gym!
https://www.youtube.com/watch?v=M1BnQNI_4CY
James Bull
Color me skeptical.
Another issue that comes to mind is every battery I know of suffers voltage drop in the cold. Most passenger planes are designed for altitude where drag is decreased and …. where it’s cold…
The only solution I see is to use really long extension cords. Maybe connected to a wind turbine.
I guess steve martin started the guide to being a United Statesian
Criticize things you don’t know about Then add
Two word foreign policy: “bomb it”
Related is, never learn a lesson, always double down and never change your tactics We just didn’t do it hard enough.
Economic ignorance is bliss because we can always spend our way to wealth.
Cost benefit studies are for wimps.
I’m sure there’s more
every battery gets warm when delivering current.
This is not the problem. The problem is the likely 45 minute duration on standard battery technology.
Depends on how fast the current is being drawn.
“The only solution I see is to use really long extension cords. Maybe connected to a wind turbine.”
Even better, if they mount the wind turbine on the plane it will be able to charge the batteries directly. won’t it?
Not disagreeing that current goes up (and heat) as voltage drops but it doesn’t help the useful energy life. And then try to charge a heated up battery.
catweazle666 says January 19, 2018 at 2:09 pm:
“Even better, if they mount the wind turbine on the plane it will be able to charge the batteries directly. won’t it?”
Exactly, and don’t forget the regenerative energy at descend, they will have even more energy then when they left. If they add solar panels on the wings one can take a flight just to charge his phone batteries for free..
I can see a problem here in that basically it’s turning a twin into a single, which limits the places it can fly with passengers, like over water.
I think you’ll find that hybrid electric have a number of advantages in terms of fuel efficiency as well as emissions. There are issues with power to weight ratios that need to be addressed.
Boeing has had its own work stream on hybrids that continues to today with NASA http://www.boeing.com/features/innovation-quarterly/aug2017/feature-technical-sugar.page
The regenerative braking system should be interesting.
Hybrid drivelines reduce energy usage during idle and recaptures a portion of braking energy. I don’t see a lot of saving for aircraft.
Maybe if they equip it with wind turbines..
good one
Hybrid works when stop and go consumes the bulk of the energy. Hybrid recovers kinetic energy which is wasted as heat and brake wear.
No stop signs in the air. Turbofan engines are already very efficient and light. Generators are heavy. Yes, electric flight is possible and capable on the scale side but hobby pilots don’t spend but 15 minutes or so in the air. And the cargo in such craft is the powerplant.
There is a reason piston power is relegated to the sub 400 HP range, above that weight matters as equivalent power weighs half as much. A PT 6a turboprop weighs about 400 pounds with prop yet has 700 HP. So even though it consumes 35 gallons per hour, its 400 pound weight savings of a 1300 cubic inch radial means two hours of flight more than the piston.
Weight is everything in flight. Generators are heavy.
“Generators are heavy.”
But the faster you spin them, the smaller they can be. Some of the micro turbine CHP plants have +50kw output from a relatively small generator.
Does it make any sense to use a smaller faster fixed speed turbine to power a larger slower fan as a series hybrid?
“Generators are heavy.” And so are batteries.
Regenerative breaks are least effective when the car is moving slowly. In stop and go traffic regenerative breaks will recover very little energy and save close to nothing in terms of break wear.
The faster the generator spins, the more shielding it will require to protect passengers in the event the turbine should fail catastrophically.
This essentially attempting to fly the aircraft using an APU (auxiliary power unit) powering an eclectic fan. APUs are used when the power needs for the electronics and avionics exceed the ability of EMAD (engine mounted auxiliary drives) to supply it. APUs are small jet engines specially designed for electrical generation.
The numbers just won’t add up in its favor.
@rocketscientist
APU’s are generally used to provide electric power and bleed air starting aircraft systems, and starting the main engines. Once the main engines are up the APU is generally turned off. Some aircraft are designed to provide power to ground crews as well – with minor modifications, for planes that land in less developed places. Fact is in the start up logic for the APU, there is frequently a WOW discrete check to make sure the aircraft is on the ground. Even the FADEC for the APU is frequently turned off during flight.
There are some APU’s I know that can be used in flight under extraordinary circumstances. 787 APU can be powered in air (especially) should one of the engines go out. I am not sure if this applies to all Twin engine aircraft rated for 3 hour ETOPS (the max distance an aircraft can be away from the nearest airport on oversea flights) and without it, it may only be allowed a 2 hour ETOPS. Military aircraft are different animals, and may, as you suggest run in the air – I am more familiar with commercial craft.
The benefit lies as I understand it from being able to size and run the turbine at constant optimum speed and use the electrics for take-off and landings. For a bit more on this and solving the weight issue see https://www.victoria.ac.nz/news/2017/06/wellington-scientists-getting-hybrid-planes-off-the-ground
HAS, the VUW paper indicates that high temperature superconductors would be required for their concept, but that would just introduce even more weight. Wikipedia states
Even at 203K substantial refrigeration machinery would be required to maintain the transition temperature.
“Even at 203K substantial refrigeration machinery would be required to maintain the transition temperature.”
Operating temp is ~30K. Basically its a solved problem. Having got it to the operating temperature, you just need to maintain it there. If you look at the link below (https://www.neri.org.nz/resource/Files/500kW%20Flywheel%20Energy%20Storage%20CFW01.pdf) you’ll see the cryocooler weight overhead is 3% in a high speed fly wheel. This is next to nothing compared with the power and energy density gains from the superconducting magnet.
Part of the novelty is the flux pump mentioned that allows the superconducting coil to be excited through the cryostat wall, so no thermal losses along current leads.
@HAS Turbines do run at fairly constant speed. They aren’t like car engines. I think you mean the turbine could be set for optimal power output per unit of fuel?
Marque2 thanks, I was being lazy and didn’t check the reason. “Analysis and design of hybrid electric regional turboprop aircraft” Voskuij et al https://link.springer.com/article/10.1007/s13272-017-0272-1 note: “A second approach to the use of batteries for propulsion is to provide additional power in specific mission phases such as take-off and climb. By doing so, the conventional gas turbines can be optimized for a single flight condition (cruise). As a result, they can be smaller (lower weight) and more efficient.”
While that can be true for ground transportation, I just don’t see the advantage for air travel.
The Norwegians have announced they plan to introduce electric planes on all routes under (if I recall correctly) 1.5 hours.
Yes, unfortunately we have some sufferers of delusions of grandeur here also….
Cue yet another round of massive tax payer funded subsidies to prop up the latest useless green mania.
Under 1.5 hours could simply equate to under 100 miles with Tarmac Time included or under 300 miles air time.
NorwegianSceptic writes: “unfortunately we have some sufferers of delusions of grandeur here also ”
If you have some data, reports and/or URL’s on this I’d enjoy reading your user contributed post on this.
“Current battery technology can only power the plane for about 100 miles….” Yeah, that should suffice!
“based on rapidly evolving battery technology”
If batteries are rapidly evolving, why do the newest cell phones last only a little longer then the one I had a decade ago?
~¿~
Well certainly. Just takes 4 stops to fly from San Francisco to Los Angeles and 4 overnights to recharge
“Good morning ladies and gentlemen, this is your captain speaking. Pleast fasten your seat belts and start pedaling so we can take off this glorious Monday. We will be departing SFO as soon as you’ve generated enough electricity to power the fans. We will be stopping in Modesto, Fresno, Bakersfield, and Santa Monica to recharge and will arrive in LAX on Friday. Please remain seated and pedaling while the plane is in flight.
Thank You for flying Air Musk”
@Bryan A
Reminds me of the Kangaroo route. Quantas created the first flight path from Sydney to London, it took 7 stops to get to London in 1947. Quantas recently sent out a press release how proud they were to be able to use a 787 to go from Perth to London in just one stop.
Yes I agree, seems a bit backwards. With all those stops it would be quicker to drive to the destination. Even 1 stop, I can easily go 100 miles in about 1.75 hours and be exactly at my destination. Even if this plane is 3x faster than my car, by the time I drive to the airport, board the plane, take off, land and find a taxi (Lyft) on the other end and drive to the location I desire – I think it would take more than 1.75 hours.
I suppose it would work for transfers. San Diego to LAX, and then transfer to an international flight.
I would be interested to see how they incorporate supplementary hydro-electric power generation.
Extension cords……
On established flight routes, set up electric cables suspended through the sky and have these “hybrid ecobirds” fly back and forth along the cables as they make their rounds, just like cable cars of yesteryear or current train routes in Norway.
Having so many suspended electric cables suspended through the sky would explain the need for the “artificial intelligence systems that avoid obstacles on a road or in the sky.”
Passengers can be charged extra to feel morally superior in their loopy-loop path as they follow the electric sky cables–the motion should be similar to that of a roller coaster and so much fun.
/s
RS spoke above about APUs providing electricity. Some can also provide hydraulic power.
So these guys think they can fly about 100 miles on electric, and Norway expects to be able to fly 1.5 hours (~400-600 miles), I say wait for the Norwegian plane.
why not use blimps?
Firstly one must delineate between the 2 classes of LTA (lighter than air) vehicles. They are class “A” rigid (zeppelins and the like that possess skeletal frames and structures with internal buoyancy bladders) and class “B” limp which require internal pressure to maintain their shapes.
(Which is BTW why they are called “Blimps” from “B” limp)
LTA vehicles have one important drawback and Blimps in particular. Volume. They require a certain density to perform (transport payloads). As they travel about and change altitude the volume of the buoyancy bladders wants to remain the same, yet the internal pressures are changing. and hence densities. To compensate for this they incorporate internal bladders called ballonets and are used similarly to the way a fish uses its swim bladder, for buoyancy regulation and control. As they rise they pump more air into the ballonets and increase their density and weight.
The problem exists when LTA vehicles attempt to traverse high mountain ranges. They need to vent the main bladders so as to avoid over pressurization, and can climb up relatively easily. The issue is when they attempt to descend the other side of the mountains. They need to replenish the loss of volume and would need to carry large amounts of reserve gas to keep themselves from losing displacement and dropping like a limp balloon.
…”why not use blimps?”
Yeah… and we could fill them hydrogen. And sell reduced-price tickets to card-carrying Liberals and Democrats.
Yeah!!
Blimps are better than ten ton flying car batteries.
Well I won’t be flying Norwegian Air anymore.
“The Norwegians have announced they plan to introduce electric planes on all routes under (if I recall correctly) 1.5 hours.”
Wonder where they plan to buy those. Norway has no aircraft manufacturing capability whatsoever.
For a small propellerdriven plane this might make some sense. You need a big engine just for takeoff. Once airborn with wheels and flaps retracted, the big engine is just ballast. If you could eliminate the starter motor and use a lighter engine then maybe the weight of the electric motor and the extra battery for a few minutes of takeoff will not add to the total weight. This will also give some extra safety in case of engine failure. For a range of 100 miles I think the battery would have to be quite large and make this less useful. An empty battery is also useless ballast, while an empty fuel tank weighs very little. Just a thought!
I tend to (partly) agree with Kai. A fossil powered engine running electric engines via a generator is definitely a superior concept in many cases (e. g. railways, ships). The problem with aircraft is, as he says, the weight of the installation. However there has been a lot of progress in small, light turbines (to a large degree driven by cruise missile requirements). However battery technology is anything but “rapidly evolving” and faces strict limitations based on basic natural laws. But a smaller battery allowing brief power surges such as during take off or emergency maneuvring might be feasible. There would be problems though, for example a rejected takeoff might require a lengthy charging session before a new try.
Hybrid cars work very well in cities where conventional cars use most of their energy starting and stopping. Apparently some folks think the same concept could work for aircraft.
“while for the descent the engine is shut down and the fans windmills to recharge the batteries”
That would require some drastic re-writing of rules. Shutting down engines in non-emergency situations is not permissible. In this case it is even worse since a go-around, or even a normal landing, would be impossible if the engine fails to re-start.
tty – “A fossil powered engine running electric engines (sic) via a generator is definitely a superior concept in many cases (e.g. railways, ships).”. Railroad locomtives and large ships typically use a diesel engine to provide electricity to power an electric motor . But it has nothing to do with energy consumption.
An electric motor shaft produces a circular motion that can directly connect to the wheel axle without using gears. A diesel engine produces an up and down motion that has to be converted with gears to a circular motion. There simply are no existing metals gears that can withstand the kind of stress needed to power a locomotive or a large ship. At least that is my understanding as to why this wasteful double engine/motor system is used on heavy loads.
“There simply are no existing metals gears that can withstand the kind of stress needed to power a locomotive or a large ship. ”
Nonsense Iowa class battleships and Midway class carriers used geared steam turbines at 56,000 hp per shaft with 1942 technology and Forrestal class carriers went to 70,000 hp per shaft ten years later.
With trains, the advantage is the low end torque of electric motors is very high.
Wind milling your engines to create power is like trying to lift yourself with your own boot straps. Where does the energy come from to power the flight forward? This is like placing a fan on the transom of a sail boat so that it can blow onto the sail to produce motion.
Really????
“A diesel engine produces an up and down motion that has to be converted with gears to a circular motion.”
A diesel engine’s up-and-down pistons turn a crankshaft in a circular motion. A diesel-electric locomotive drives the alternator directly from the crankshaft, so no gears are involved in the electrical generation. There are, however, gear boxes between the electric motors and the drive axles.
[? .mod]
“Where does the energy come from to power the flight forward?”
During descent you convert energy of position into kinetic energy. Windmilling the engines will result in a steeper descent with a greater sinking rate. It is perfectly practicable.
You are right, taking off is the issue. Better solved with some sort of catapult (no kidding, this is used by air forces and for glidders, and work upon for commercial planes), In any case, you have rather extra cargo or passengers than useless weight, so for battery to economically fly you need it to weight less than the fuel it replace. While, as you point out, “An empty battery is also useless ballast, while an empty fuel tank weighs very little”.
The just need to put the aircraft on a downward sloping ramp to pick up some momentum before takeoff. They could even mount it on a rocket-sled to get it moving then drop the sled after takeoff (See V1 rocket, “When Worlds Collide” or “Fireball XL5”).
@RicDre
The concept I saw (internet is your friend) are indeed the kind you mentioned. You may add towing: a high powered aircraft tows the long range, cargo/passenger filled, aircraft at high enough speed and altitude, then goes back at airport to do it again with next.
Now, it is easier to get the idea (and even make it work for gliders), than to have it work for real for airliner.
What about using JATO (Jet assisted take-off)?
It’s called the Space Shuttle.
JATO existed long before the shuttle. End of WWII.
I remember seeing a video of a small missile we worked on being launched off the deck of a Navy ship using 2 bottle rockets strapped to it (JATO). When one of the bottles didn’t ignite the deck area got really exciting really fast! I’m sure the Captain had a stroke when he saw a missile spinning around on the deck with no way to shut it down except let it run out of fuel – hopefully before directly impacting any critical structure.
That was one of the fears they had with the shuttle. That only one of the bottle rockets would fire.
Operation Deep Freeze in the 1950s used JATO fitted DC3s to take heavy loads from Invercargill at the south of New Zealand to McMurdo Sound in Antarctica. Stories have it that a DC3 on the runway approached V1, the button was punched—and the bottles failed to fire. Apparently the DC3 trundled off the end of the runway and came to a halt in marsh.
Electric planes are one thing. Battery powered are another. I can envision turbine electric, but batteries add an entirely new weight and logistics complexity.
Turbines are becoming smaller and smaller and the gearboxes for propellor driven aircraft are an enormous proportion of the weight. If electric motors are comparable in weight and the power losses from the turbine to the generator to the drive motors keep reducing to a competitive level, then why not? To call this configuration “green” well…perhaps that’s just to comply with requirements for grants.
You are going to need a turbine/generator combination capable of creating enough power to get the plane airborne. This means that the output of the turbine is going to be pretty close to whatever you needed to get the plane airborne in the first place, plus enough to overcome the losses in the generator and electric circuits.
If you posit a battery to provide extra power during takeoff, that does mean you can shrink the size of the turbine, but you are adding the weight of a battery that your plane has to carry all of the time.
I just don’t see how the claimed increases in efficiency are going to be enough to compensate for the weight of all that extra equipment.
“There are issues with power to weight ratios that need to be addressed.”
You’ll pardon me if I don’t hold my breath?
Emissions? Warren Blair is right. I get so tired of these virtue signalling boondoggles.
The next step is to launch it with a giant rubber band and plaster the top wiith solar panels to promote eco-sales. It might be highly dangerous and have a very limited range and huge potential for risk on take-off, but what the heck, it’s just what the Greenie CAGW gang wanted.
Wait a minute! The electric plain already exists. It has flown around the world. There are a few slight drawbacks, such as a maximum speed of 60 mph and a passenger load of zero, but it’s a start.
They want it for other suckers – not for themselves. They want to be on an Airbus A380 business class drinking gin and heading for the latest climate conference in some exotic location.
I thought hydrogen was best for planes due to its weight vs power ratio being better than jet fuel.
Contrariwise. Hydrogen has very low power density per volume. Hydrogen powered aircraft are perfectly feasible, but would be HUGE. Indeed so large that airports would have to be completely reconstructed.
Type hydrogen into Google plus Hindenburg. Hydrogen didn’t work out too well. Didn’t work out to well for many other “airships” before then either.
@Les Francis Hindenberg didn’t burn up from the hydrogen. The outer skin was highly flammable, made out of cotton and nitrates (basically similar to gunpowder) While the exact cause of what started the fire is unknown – it is known that the frame didn’t disperse static well, and any spark could have caused the ignition. Inside the bladders, with 100% hydrogen, there was nothing with which the hydrogen can combust.
Note too, all the yellow flames you see in the videos are indicative of carbon fires. Hydrogen fires are too high a frequency to be visible to the eye. When the skin burnt, the hydrogen probably burnt off relative slowly as it mixed with the oxygen outside the airframe.
I read somewhere that the aluminum compound that the skin was doped with (to reflect sunlight) was similar to thermite, and once it lit up there was no stopping the fire.
Nitrate dope is still obtainable…
http://www.aircraftspruce.com/catalog/cspages/dopesthinnrsolvents.php
What is this ‘rapidly evolving battery technology?’
I reckon the only aircraft that may sensibly be able to use electric power today are airships.
No. An airship has strictly limited lift capacity, it certainly can’t afford to carry heavy batteries.
tty: ..”An airship has strictly limited lift capacity”..
True for Blimps (gas bags) not so rigids. Lift capacity is displacement ,(volume) double the dimensions —> 8X lift.
Mike
Strictly limited per volume. Double dimensions -> Quadruple drag.
There is yet one more limiting factor in merely “scaling things up”, namely strength of materials. There is a universal limit know as the square-cubed limit for materials. It is limited by the fact that weight (mass) rises with the cube of dimension (volume) while strength which relies on cross-sectional area only rises with at the square of dimension (area).
This dictates that load (weight) rises much faster than strengths as things get scaled up. So eventually as things get enlarged it will grow to the size where it collapses under its own weight.
Yes indeed! The Airship!
Lift is free, carbon composite rigid hull, vectored thrust motors, Helium lift Hydrogen fuel (+ lift), all available off the shelf technology today. Point to point at 150+/- knots anywhere on the planet (almost). No runways airports needed.. huge upper surface area for solar panels (optional extra).
“all available off the shelf technology today”
Could I please get the name of companies who own autoclaves big enough to cure carbon composite airship hull members?
Also the companies who would undertake to construct such hulls. Rigid airship hulls are rather complex to put it mildly, and as a matter of fact nobody but the Zeppelin company ever managed to build even reasonably successful ones.
one word: Balsawood. 😉
RS spoke above about APUs providing electricity. Some can also provide hydraulic power.
So these guys think they can fly about 100 miles on electric, and Norway expects to be able to fly 1.5 hours (~400-600 miles), I say wait for the Norwegian plane.
150 knots. Not likely, or, probably, possible.
Sorry, the first comment here is out of place – it was a comment about supplying hydraulic power and should have appeared earlier.
“one word: Balsawood.”
Wooden rigid airship structures have been tried. It didn’t work very well:
https://en.wikipedia.org/wiki/R31-class_airship
@ TTY
List of companies capable of autoclaving airship parts:
Northrop-Grumman
Boeing
Lockheed-Martin
Aerospatiale
There are undoubtedly more.
BTW a rigid airframe LTA is being built in Tustin CA currently. It would be safe to assume that somebody is building the composite parts.
The frames and members are NOT continuous stem to stern. Too impractical to ship and handle for assembly.
The airframe is made up of lots of smaller pieces that are bolted together.
Glued might be more appropriate for composites.
Perhaps they will come up with a way to 3D print them whole.
This electric plane thing is completely nuts. I own a small 4 seat plane, it burns 15 gallons of gasoline per hour. An hour flight is minimum reserve you want on top of your planned journey before taking off. After the batteries are exhausted they are dead weight. I don’t get where the CO2 saving is supposed to come from.
And a purely battery-powered aircraft could never even be licenced under existing regulations. Remember the “alternate plus 45 minutes” rule. A battery-powered aircraft would probably be in violation of this even before takeoff. Hence the need for a fossil-powered extra engine.
It’s a hybrid.
Exactly. And it has to be able to fly without the batteries. So why have them?
spot on, tty.
batteries are just dead weight
Batteries allow you to use a smaller turbine for the generator. The battery provides extra power during takeoff.
Of course the battery is still dead weight for the rest of the flight. It’s an open question whether the savings in turbine/generator weight will be less than the weight of the battery and the electronics needed to manage it.
Maybe they are looking ahead to the time when the CO2 boogieman has disappeared and something else takes its place.
Using an electric motor to wind up a large rubber band which would drive a propeller, that would power a balsa wood plane I had several as a child, the only disadvantage I found with all of them was that the wings used to fall off when they nosedived.
“After the batteries are exhausted they are dead weight.”
At that point, the batteries can simply be detached from the fuselage and dropped into the nearest battery-recycling pond. The benefits of Green-think go on and on.
/s
LOL SPLASH.!!
heads up 150lb a/c batteries enroute LOL
Maybe the solar cells on the wings (j/k)
“The planes eventually would fly solely on battery power, and are being designed to fly with one pilot and to eventually be remotely piloted, he added. ”
Well I don’t know about you guys, but I regard the pilot of a plane the best insurance against crashing the show. Wont catch me going on any plane with only a remote pilot.
Cheers
Roger
http://www.rogerfromnewzealand.wordpress.com
That depends. It was probably more true in the past when airline pilots were usually the pick of ex-military pilots with superior piloting skill and safety consciousness (in accordance with the old rule: ”there are old pilots and bold pilots but no old, bold pilots”).
Today pilots sometimes lack the experience to handle unexpected situations when the autopilot gives up and gives the authority back to the pilot. A very good example is the AF 447 crash. I have discussed this with several military and ex-military pilots and they all agree that a pilot with practical experience of flying at (and occasionally getting beyond) the edge of the envelope would immediately have realized that they were in a stalled condition and gone nose-down and full power.
Of course there was additional circumstances involved, such as a positively dangerous stall-warning logic and inferior pitot tubes (before this crash I thought that pitot tubes without heating had gone out of use in the 40’s, I’ve certainly never seen one).
I was told by somone who designed (until recent retirement) fly by wire software to provide controls with ‘feel’ that once the experienced pilot woke up they did that but were 500′ too low to recover.
tty Not the same circumstances, but the pilot of US Airways 1549 in 2009 landing in a river
Yes, this is a good example of a very skillful pilot doing something that an autopilot almost certainly could not have managed. There are many others: Air Canada 143, UA 232 and AA 96 for example.
The pilot is certainly not the insurance, it is the cause of most crashes, whether on purpose, just by mistake, or other failure (medical condition, hijacking,…). And, actually, in modern commercial aircraft, the pilot do not really pilots anymore, computers do it all.
The sooner the pilot disappear, the better for the safety. Even more so if he is remote, though
Actually computers do it mostly, but not all, as in the case I mentioned above. There is no problem with autonomous operation on long transoceanic routes. The difficult bits are takeoff and landing. One must also realize that in large parts of the World there is nearly zero ground infrastructure. The US by the way is somewhat primitive in this respect, with a large proportion of domestic airports with limited facilities plus the problem of flying in “indian territory” with large numbers of private aircraft operating on “see and be seen” basis.
And actually pilot error is very rarely the only, and not often the main, cause of a crash. With modern aircraft it usually takes a whole series of circumstances to cause a crash, and most of these would be operative with an autonomous aircraft as well.
The one type of crash that would definitely be eliminated is pilot suicides. However this is largely confined to moslem pilots, though this is hardly ever mentioned.
“The difficult bits are takeoff and landing. ” Indeed. And the more difficult the bit, the less humans are reliable. Remember that training (to be a pilot, or whatever) is nothing but turning part of our brain into a machine that will, without even thinking about it, execute needed operations, as defined by the operating manual, and by ignoring what his own senses and every day habits are telling him (plane’s artificial horizon is right, pilot’s vestibular system is wrong). A machine will do it better, even without ground infrastructure.
I agree with you, “With modern aircraft it usually takes a whole series of circumstances to cause a crash, and most of these would be operative with an autonomous aircraft as well”, but the main point is rather: would a pilot prevent more crash that he would contribute to? And the answer is: no. Even if a decision could reverse a looming disaster, a man reaction time is higher that a machine’s a few hundreds milliseconds when he act purely in reflex, several seconds when he has to think on information readily available, and even more when he needs to gather information on multiple displays. In emergency, that’s seconds lost just when you cannot afford.
An additional impediment to autonomous flight is that the FAA has not yet issued regulations covering autnomous flight in the National Airspace System (NAS). The rules recently issued cover altitudes up to 400 feet, and the aircrafdt controller must be within line-of-sight of the aircraft (hence, not autonomous).
The FAA takes flight safety very seriously, and has been looking into integration of autonomous and remotely-piloted aricraft into the NAS for at least a decade. I don’t expect to see any regulations soon.
paqyfkyc,
I don’t know, the transoceanic airbus losses have been flight control failures in the fly by wire computer system. In an Airbus the pilot does not fly the plane, the computer flies the plane in accordance with inputs from the pilot. If the fly-by-wire computer fails there is no control whatsoever, and if the computer introduces porpoising the wings will eventually break.
In particular I am thinking of the flight from South America that crashed in the middle of the Atlantic. The debris field indicated the plane broke up in flight. The only things I can think of that can cause that is extremely violent thunderstorm turbulence way beyond the usual or flight control induced uncontrolled porpoising.
In my Air Force days, most crashes were caused by overly bold pilots exceeding the flight envelope, pilots losing situational awareness on fellow flight members causing a mid-air collision, or unexplained “controlled flight into the ground” probably caused by target fixations. There were only a very few that I can think of where the airplane broke and caused the crash in military operations. Redundancy is built into almost everything in aviation, but I can think of about 20 cases where a catastrophic failure of the aircraft was brought home safely by astute pilot actions.
OweninGA, I don’t agree entirely with paqyfelyc, but in the particular instance of Air France 447 the pilots destroyed the airplane after misinterpreting conflicting airspeed indications. Ironically, the autonomous system bailed out, dumping the problem on the pilots. Hmmm…. maybe we need a third way.
Old Man Winter gets my point entirely.
A pilot on the plane has a vested interest in everyone’s safety, including his own. Conversely one can imagine a warehouse of little booths somewhere on the ground where ranks of “pilots” are flying 2 or more planes each. Apart from the possibility of power blackouts, communication or down link problems, if one or more of the planes go down because he didn’t see a hazard or whatever, he is still safely at his desk
rogerthesurf January 19, 2018 at 2:07 am-
+10
It’s obvious to me that all those glib comments
advocating pilot-less aircraft come from rubes
who have never had ground controllers try to vector
them into big a$$ thunder bumpers!!!! Or they
have completely ignored all the computer glitches
and hacks they have had! There is so much that
goes on that passengers know nothing about! And
you definitely don’t want to know what they are!
Any pilot you know with a couple hundred hours of
flight time has already probably cheated death
several times & his memory of those events is
what makes him fly a bit “scared” whereas to a
ground controller it was just a mistake and it
doesn’t carry that same weight. So having a pilot
on board whose life depends on getting it right
as an insurance policy is a really good idea!
Since all corporations today are driven by legal
and finance, an even better idea is to have the
CEO, CFO, and the head of legal on board every
flight as an insurance policy especially if they
go pilot-less. If we do crash, at least I will
have taken some of the probable causes of the
crash with me! 😉
You know what they say down Texas way: “When the weather is good, fly IFR, when the weather is bad fly VFR, so you can dodge the thunderstorms”.
Most people don’t realize that weather can still be quite dangerous to aircraft. I remember once sitting for an hour and a half on a taxiway on Kansas City Airport waiting for a small but nasty thunderstorm that had parked itself just beyond the end of the runway to either move off or die down.
The San Francisco 777 crash was due to the pilots not knowing how to land the plane without autopilot. Commercial Planes have been capable of taking off and landing by themselves since the 767 where the routes we’re loaded on 8″ floppy disks. It wouldn’t take much effort to correct the 777 issue so the plane could land with ground guidance off. I think the next generation of planes would be safer safe piloted with only people’s insecurities keeping pitots aboard.
Self- flying aircraft! That reminds me of a very old joke about a computer controlled airliner. With the pre-recorded announcement, saying that everything was duplicated and cross checked, so “nothing can go wrong (click), wrong (click), wrong (click)…..”
More details here …
Boeing-Backed Zunum’s First Aircraft To Be 12-seat Commuter
o 12-seat economy or nine-seat business/economy configuration
o 700+ mi. range, 340-mph speed on current battery technology
o Targeting operating costs of 8 cents per seat mile, $250 per hour
o Similar size to the PC-12, but 3-5 times lower operating costs
http://aviationweek.com/new-civil-aircraft/boeing-backed-zunum-s-first-aircraft-be-12-seat-commuter
Ever heard of an actual case where the first application of a new and untried technology resulted in 67-80% reduced operating costs?
Particularly when was based on a more complex technology (both turbine and electric engines).
I guess you could actually find a few cases where operational cost were indeed cut in the promised range, all of them paid for by a x3 to x10 in capital cost (which, for some reason, they failed to mention in their advertising…). No free lunch.
I can’t find where Boeing or Zunum claimed a 67-80% reduction in operating costs.
I think if you’re looking for something roughly equivalent in the history of technology, diesel-electric locomotives might be appropriate. They started small working in switching yards and eventually replaced steam locomotives everywhere. High tech in its day.
No technology lasts for ever and nothing new takes over “overnight.”
Popular Mechanics used to run articles like this; all about some dreamland transportation method and mode.
None have come to pass.
Most other forms of battery powered forms of vehicular motion use electric engines because they’re quiet and can be temporarily exhaust free; various pallet movers, commuter rail.
Ships use electric motors for maneuvering and docking.
Large trains may use electric engines because they must shut off the diesel engine in tunnels and dense urban areas.
Nuclear ships and submarines use electric motors.
None of those uses are for fuel efficiency or lower emissions. They are purpose designed to meet certain conditions.
Why bother installing a fossil fuel engine into an allegedly electric plane? That airplane design doubles weight for a false façade.
I suspect, there are significant grant funds waiting in the wings, just waiting for daft ideas and efforts claiming to benefit efficiency/emissions/whatever.
That plan already dumping a pilot sounds like a weight reduction ploy.
“Automated flying” may sound great in a press release. To accomplish “automated flying”, system designers programmers must design and code many thousands of lines into their programs.
Meaning every action by the plane is dependent upon someone planning for that action and that there are sufficient sensors supplying the correct information needed as input.
Coding errors, bugs, oversights, etc. are certain life or death issues in a plane; planes without a pilot means problem solving will be dependent on some bored overworked air tower drone employee. Planes plummet from 7.5 miles (12.2km) high rather quickly during that period while some bleary eyed worker tries to come up to speed on what plane, what technology, what error/fault…
Interesting that they claim these planes target the short commuter plane flights.
One wonder if they swap new charged battery packs into the planes, or whether the planes sit charging.
One also wonders how long these planes can wait in line on the tarmac. e.g. A three hour delay parked on the tarmac.
I’d rather drive.
ATheoK –
Good points, however, they are electric motors, not electric engines. Secondly, in a diesel-electric locomotive, the diesel engine drives a generator (or alternator) which, through a great deal of control logic, powers electric motors geared to most or all of the axles.
Diesle-electric locomotives do not turn off the diesel in tunnels. However, there were some locomotives built that had, primarily, a diesel-electric drive and either third-rail or pantograph pickup such that they could shut off the diesel in tunnels. For example, the Electro-Motive Division FL-9 used by the New Haven in Grand Central Terminal in New York was so configured.
Few railroad tunnels are long enough to require special exhaust treatment or alternative engine-electrrical hookups to maintain (or replace) diesel power in the tunnels. But it does happen.
The older steam-coal locomotives in the long tunnels out west did foul up the tunnels under the Sierra Mountain bad enough that the Union Pacific railroad developed “cab-forward” steam (coal-fired) locomotives that put the engineer and stoker at the front, then the exhaust behind. That worked for freight trains, but still fouled up the passenger train cars behind the engine.
One tunnel near Seattle uses a clever arrangement of wind blocks to seal eastbound traffic against the prevailing winds through the tunnel. West bound trains let the prevailing winds blow through with the exhaust cleared out by the natural wind.
Most tunnels though are short enough that it exhaust adequately, if not comfortably, by the natural winds. Exhaust fans are often used like in automobile highway tunnels.
Train locomotives require excess weight be in the locomotive to create the pulling force by the wheels – round steel wheels on rounded top flat steel rail tracks have little contact surfaces. So the weight penalty of electric generators and electric motors on each axle is an advantage to trains, but is near-fatal problem in ships, tanks, and airplane electric drive trains.
Also, as mentioned above, planes require low torque at high shaft rpms for either propellers or fan jets, but locomotives require very, very high torque at very low rpms (zero rpm when starting the train!) so the electric motor’s low-rpm torque is another advantage. Ships require high torque but very low but variable speeds for the propeller shaft so the propeller avoids cavitation. That makes ship electric drives attractive since the 1900-1910 time frame, but the better economics of steam turbines and reduction gears won out over electric drives. Today’s superconducting motors and higher-efficient rare earth magnet motors are making “some” electric drives valid for low-noise (submarine and warship) ship propulsion systems.
You are, of course, correct regarding the terminology and technology.
Thank you for the corrections.
Excellent description of details RACookPE. Thank you.
Some of those urban tunnels are prone to train traffic jams at times. Even a one mile long tunnel becomes hazardous with running engines, er, motors. Or is that both?
>> 12-seat economy or nine-seat business/economy configuration
RINNNG.
HELLO?
This is the 1930’s calling. We want our 12-passenger DC-2 https://en.wikipedia.org/wiki/Douglas_DC-2 and 21-passenger DC-3 https://en.wikipedia.org/wiki/Douglas_DC-3 back.
Interestingly, Douglas Aircraft merged with McDonnell Aircraft to become McDonnell Douglas, which was later bought by Boeing. So Boeing owns the licences/rights to build the DC-2 and DC-3.
Build the DC-3 as a turbo-prop from day 1, instead of doing an expensive after-the-fact conversion. and you’d have a very competitive short-haul aircraft. Heck, even a piston-engined version with today’s electronic fuel injection would be pretty decent.
Okay by me as long as it’s not on the taxpayer dime.
dramatically reducing the travel time , really!
So by what ‘magic’ does the use of electric motors overcome aerodynamic other factors , such has airport capacity , that control travel times ?
I doubt that the hybrid-electric scheme will improve efficiency, but it might buy some safety margin. Burt Rutan’s SkiGull is mainly gas-powered, but it also has a pair of auxiliary electric motors with folding propellers, which can provide a boost on takeoff, or can fly the plane for eight miles if the gas engine fails. Electric motors are very reliable, and if your gas-powered engine(s) fail, having electrics with even a small battery might let you limp to the nearest airport (or to the nearest lake, for Burt’s SkiGull, since it’s amphibious).
BTW, thanks for the link to that LAPD electric police care boondoggle story. Amazing stupidity on display.
If the battery is exclusively for emergency use I would suggest a thermobattery. They develop a lot of power for a limited time, but are strictly one-time. The SAAB JAS 39 has one that can actually run the whole flight control system for several minutes in an emergency.
Battery landing (and if possible battery-assisted take-off) might make sense for noise reduction purposes, helping the continued stratospheric rise of air travel … and emissions.
Se we arrive at our long range destination . The batteries are close to exhaustion and we are relying on the subsidary fossil fueled battery boosting engine to provide enough power to keep us airborne until we land.
The destination airport is socked in wwith weather but we really have no options left so a landing is attempted. Close to touchdown and its obvious we have to go around for another try.
Go Around !
What the hell have we got left other than a farty little engine powered battery boosting generator thave we got left to try and go around with ?
——–
So who now who is going to pay for the new power generators and the wiring and the heavy electrical infrastructure needed to recharge those batteries after an electric airliner has landed .
Or are the promoters of this whole electric propulsion bubble going to expect the tax paying public to fork out yet again another huge slice of their hard earned monies to provide all the infrastructure, all the electrical power generators and the wiring and the transformers and switching gear that will be providing the intermittent power demandsfor charging the batteries.
Ofcourse the wind generator companies might believe there is a lot of profits to be made in providing batter boosting power for those electric aircraft. Just thart all those electric airliners will have to sit on the ground and wait until the wind starts to blow so that they can charge their main flight batteries.
Over the last century the fossil fuel powered vehicles ENTIRE supporting infrastructure, fueling and the building of service stations , the entire refinery industrry, the refining of oil to fuels, vehicle repair and maintenance industries, parts industry and many etc’s other than tax payer funded roads and even here roads are mainly finannced by fuel taxes, were created through the profits made by private industry in their servicing of the vehicle industry in all of its enormous range of applications and the reinvestement of those profits back into building the entire infrastructure that we see supporting road [ and rail ] transport today..
And nowhere in those early days of vehicle development when the foundations for the vehicle industry as we know it was being created , was there government subsidies and government mandates favouring one make or another over others or some technologies over others .
Governments never had the resources to choose any one technology or manufacturer over others and then throw money at them to justify their choice.
And so there now exists one of the world’s largest industries, the remareable and highly flexible automotive industry that has given mankind the extremely personal and flexible mobility we have never ever had in all our previous history.
—————-
Now it appears that the electric vehicle / proplusion industry is expecting, demanding in fact that governments / tax payers fund the entire supporting new power generation and power distrubution infrastructure for electric vehicles .
That NEW and additional to the current power generatins systems and distribution infrastructure has to have the similar energy generation and distrubution capacities equivalent that which is to be found in the petroleum/ diesel fuels that it intends to relace and which the electric vehicle industry believes will no longer be used as widely due to the influx of electrical propulsion systems.
Nobody nowhere seems to have ever considered this immensely costly compensating factor needed when one distinct fuel type replaces another entirely different fuel technology which was formerly used for an identical purpose.
Tax payers are apparently expected to pay for the building of a whole new group of specifically intermittent vehicle battery charging power generators that will provide electrical power on an intermittent basis when and if demand for the charging of electric vehicle batteries is demanded .
And do so in the amounts which will replace the energy of the petroleum fuelled systems currently used so conviently if and when required in the amounts demanded by all forms of vehicle and propulsion systems i.e.; aircraft, today.
Tax payers SHOULD NOT be forced to pay in any way for electrical generators and electrical infrastructure for a system which may or may not work or become a viable vehicle propulsion system for many years or even decades ahead and which may remain the province of no more than the wealthy few who can afford those plush electrical vehicles.
Tax payers should not be forced by a small and wealthy green bureacratic political and media elite to pay for their dreams of an entire system which will only ever, for as far as can be seen into the future, to become only partially electrified as the sheer versatility of the petrolleum and diesel powered vehicles across every horse power range continues to be such a fundamental advantage of fossil fueled vehicles.
Electric vehicle manufacturers, owners and proponents should be required as did the fossil fueled vehicle industry , to establish the infrastructure required to fully service the electric vehicle industry to its full requirements from the sales and profits to be made from the sale and use of electric vehicles.
If the electric vehicle industry cannot do this without massive tax payer support, its advantages over fossil fueled vehicles are too poor and insufficient and do not exhibit enough technological and public and community advances so as justify and to warrant the immense expense required to transfer even a small part of the global vehicle fleet over to electric vehicles.
In short, for those who demand electric vehicles. let them as did the fossil fueled industry of a century ago and continuing to do so today, to use the profits to be generated and made from their own electrical vehicle industry to build an infrastructure specific to and suitably configured to the use of electric vehicles and its proposed industry.
I suppose the turbine will be an APU-type installation that can be run on the ground to charge the batteries. Might be some environmental complaints about it since APU’s tend to be very noisy, particularly when installed in small aircraft. For example the original APU in the SAAB JAS 39 was so noisy it had to be replaced. The mechanics used to say that the JAS 39 was the only aircraft in the world that grew quieter when the engine was started.
A turboprop plane has a gas turbine engine. This hybrid plane has a gas turbine engine, electric generator, batteries and electric motor. It’s heavier, more equipment, more maintenance, more complicated, more expensive, less fuel efficient. What’s the point?
Not necessarily less fuel-efficient since the turbine could be run almost exclusively on its “sweet spot” with power surges accomodated by the batteries. But heavier, more equipment, more maintenance, more complicated, more expensive, yes.
The batteries have a range of only 100 miles. It will run on gas turbine 85% of the time. The efficiencies of the electric generator and motor are 80 to 90% each. At least 20% energy loss from that combination.
Actually both are rather better than that. And propeller gearboxes aren’t lossless either and quite heavy and expensive to maintain. I think it is quite conceivable that a turbine/electric combination might be competitive some day. It will need a lot of development though.
When it comes to planes, heavier is also less fuel efficient.
“…it is quite conceivable that a turbine/electric combination might be competitive some day.”
Ah, yes, but by then, we can simply put a saddle on a pig and fly wherever we wish, at no cost.
“Not necessarily less fuel-efficient since the turbine could be run almost exclusively on its “sweet spot”
I think you’ll find that on all current turbofan engines the cruise setting is its “sweet spot”.
Turbine-electric makes sense in diesel-electric locomotives because it gives maximum torque instantly and at low engine speed. It doesn’t make sense in airplanes unless you want to takeoff in an aircraft carrier.
“A supplemental jet-fuel engine and electrical generator would be used to give the plane a range of 700 miles and ensure it stays aloft after the batteries are exhausted“
In order to obtain certification for fare paying passenger operations, a “twin” will have to demonstrate the ability to climb away from a missed approach on one engine. A single “supplemental” engine might be O.K. for continued flight after the batteries are exhausted (although losing one engine usually means they have to continue at a lower altitude or speed). But to meet the climb-away requirement the supplementary engine/generator will need to be sufficiently powerful, (when faced with the dead-weight of the batteries), or there must ALWAYS be sufficient remaining charge in the batteries to assist. Both of which defeat the whole point of this exercise.
One of the unstated advantages of not having a pilot is that in the event of a fatal crash, the pilot doesn’t get killed. Think outside the box, people!
Good irony. The pilots will be happy. And maybe there will be a few world improvers less until the technology matures. It does not reveal to me why in the world a 12-seater should be economic. If already 200 seater -Airlines are threatened by bankruptcy. This is just another step for Giant-Tech (Computer and Intel) companies to a) save tax via deductibility of research and the resulting losses and b) to mask that they are actually responsible for ensuring that CO2 emissions do not go down. A little coat of St. Martin for the poor. Which just recently can retrieve several hundreds of billions of stolen profits to the USA. More Bitcoins!
One of the advantages so having a pilot is that we will trust the pilot to d the pre-flight check since he is getting on board also. Not sure if I would trust a pre-flight inspection by someone who does not have any skin in the game.
Very true. This is the main reason incident reporting systems have generally been quite successful in the aviation field, but rarely elsewhere, and that there is somewhat less cover-your-ass mentality than in other industries.
One of the REALLY unstated advantages of not having passengers is that in the event of a fatal crash, the passengers don’t get killed, either!
The only box you have to think outside of is the coffin each (non)passenger doesn’t need to use.
Make these planes for cargo hauling–I’m sure FedEx, with a huge demand to support our burgeoning economy, would be the market to penetrate first.
The pilot doesn’t have a job either.
Trebla, these people are thinking not only outside the box, but outside sanity and are quite likely to drop their box on our heads.
If the motivation is cheaper, then everyone should applaud. Otherwise, it just exhibits how the global warming caused by CO2 crowd continues to win.
I don’t get it. Under electric power what actually propels the plane? I thought the turbine fans were turned by the escaping gas which actually propels the airplane.
To what is the electricity applied to actually move the plane forward?
A turbo jet is essentially a shrouded propeller
Some people consider a high bypass turbo fan as essentially a shrouded propeller (the FAA never much liked that idea, though.) A turbo jet is essentially an air oxidized rocket. Both the turbo fan and turbo prop engines can be described as a jet engine blowing on a pinwheel (turbine) that spins a fan or propeller. In a turbo jet all the thrust comes from the hot, high speed engine exhaust while in the turbo fan most of the thrust is from the slower moving air from the fan that flows around the jet, not through it. An electric fan-jet is certainly possible, maybe even easy, but until the energy density of the battery gets a lot closer to that of jet fuel it will not be very practical in the real world.
OK – that helps. Thanks
Every single one of these hybrid battery schemes presumes that the electric grid is available upon demand to supply an enormous amount of power to recharge the battery. In the case of battery airplanes and battery over the road trucks, the instantaneous demand on the utility is a staggering amount of kilowatts. Wait until the utilities wake up to the provisioning implications of having someone plug in a few airplanes. Their demand charge will change every cheery cost projection for the worse.
Actually no. Utilities are worried about going the way of ma Bell. Demand growth is stagnant. Adoption of electric transportation modes is good for utili
Then the millions utilities are throwing away on wind power is wasted, both in lack of performance and in lack of need? What evil human beings—destroying the environment, killing raptors and bats while building an unneeded product. GREED runs amok, I assume. Or are they hoping demand declines so their lies will not be blantantly obvious even to the most stubborn and uneducated?
“Utilities are worried about going the way of ma Bell.”
Sure they are. Have any good ideas about what might replace electricity? It would make a rather interesting investment opportunity.
Actually Ma Bell didn’t fail, it was broken into a bunch of smaller pieces by the Federal Government. Eventually, through mergers and acquisitions, Ma Bell reconstructed itself into the current version of AT&T, but by the time the reconstruction was complete, technology had moved on and AT&T never regained its form “Glory”.
There are various technologies available to buffer the energy from the grid and release it in short discharges. Classes of batteries, supercaps and flywheels can oblige, see for example one technology that is in development https://www.neri.org.nz/resource/Files/500kW%20Flywheel%20Energy%20Storage%20CFW01.pdf
Interesting, but dubious. For aircraft, everything is about weight. Which is why they’re made out of aluminum and composites instead of steel, despite it being much cheaper. And why piston-propeller aircraft use gasoline instead of diesel engines, despite their better fuel economy. Take all the the disadvantages of pure electric cars and add in another penalty for weight and you have an approximation of the problems with electric planes.
The other major factor in running a profitable airline is turnaround time — the plane only makes money when it’s in the air. A commercial aircraft can be re-fueled in less time that it takes to get the arriving passengers off and the departing passengers on. Adding an hour or more to the turnaround time to recharge batteries could cut the daily flight time in half for short commuter runs. Maximizing the number of passenger miles per aircraft per day is the way to pay for those expensive planes, and for short routes that means minimizing turnaround time.
Take the inter-island service in Hawaii for example. No route takes more than about 50 minutes in the air and they can turn the aircraft around and get it carrying paying passengers back the other way in another 40 minutes or less. And they can keep that up all day as long as there is demand. There have been several attempts to make a go with inter-island ferries, but none have succeeded because the airfares are too low. I suppose using electric planes in Hawaii might be a way to make ferry service competitive …
..or why not cut costs with electric ferries?
you have to ship diesel a long way to Hawaii…
In use in Norway…
http://corvusenergy.com/marine-project/mf-ampere-ferry/
It has been tried in Sweden too. It works just fine as long as you can get the power from a cable (which rolls up on a big wheel on the ferry) and reasonably well with batteries for very short distances, and small ferries like in Norway.
But all efforts to introduce it on the big ferries between Helsingborg and Elsinor in Denmark (5 kilometers) have failed. It just isn’t possible to recharge the batteries fast enough.
By the way Griffie, how do you think the fuel for the power stations arrive in Hawaii? By teleportation?
I think Griff meant electric fairies.
The only real way to recharge batteries would be to keep a supply of charged batteries in port and change them out when the ship comes into port. Then recharge the exhausted battery for the next return trip or after two trips. You just need to have charged batteries waiting and exhausted batteries recharging at the same time in every port.
Here you go, Grifter!
WORLD’S FIRST ELECTRIC SHIP NOW SAILING IN CHINA—AND HAULING COAL
http://www.newsweek.com/worlds-first-electric-ship-now-sailing-china-and-hauling-coal-740015
Griff:
The Sognefjord ferry you reference makes 34 daily trips of 5.6 km (3.5 miles). Ferries in Hawaii would have to travel much further. For example on the big island the largest port is Hilo on the east side, and the distance from there to Honolulu is 218 miles as the crow flies — probably about 60 miles more the way a ferry would go. On the west side of the island there is smaller port in Kawaihae which would be about 80 miles shorter. Other inter-island routes are shorter, but nothing is anywhere near the 3.5 miles your electric ferry travels.
The most recent attempt at inter-island ferries was the Hawaii Interisland Super Ferry, which started service in 2007 and shut down in 2009 due to an Hawaii supreme court ruling over environmental impact statements. At the time, they offered fares of $70 per person or $110 for a large van. I can’t find a schedule to figure out the passage times, but you can figure it out from the average ferry speed of 20 knots (23 mph). The airlines will get you between any two islands in an hour or less.
If you want to travel between Hawaiian islands and take your car, the demise of the ferry is sad. But the one-way passage on Hawaiian airlines (fossil fueled, in case you were wondering) is basically the same as the ferry charge and for a short trip you can rent a car for less than it would cost you to transport a vehicle.
Personally, I miss the romance of travel by sea. I would have loved to have lived in the era of the great ocean liners between the wars. And I would love it if there were ferry service in Hawaii, but the combination of economics and time makes ferries uncompetitive with air travel. And electric ferries make that comparison even worse.
“WORLD’S FIRST ELECTRIC SHIP NOW SAILING IN CHINA—AND HAULING COAL”
Gives some interesting data on what electrical ships can accomplish with current technology:
Range: 50 miles
Speed: 7 knots
Cargo capacity 2000 tons
Battery capacity 2400 kWh
Charging time 2 hours (implies about 1.5 MW charging current)
Ergo, useful for hauling moderate volumes of cargo over very short distances in calm water and weak currents in areas with a good power network.
Perhaps a ‘fireball XL5 type launch sled (without the rockets!), then preserve enough power for a ‘go round’. That would be cool – 1960s puppet technology!!
Why not just bring back dirigibles.
I bet some watermelons actually believe there would be feasible to just attach windturbines to charge the batteries in flight…..
the belgums had an electric plane in development in the 90s, but they had to abandon it due to problems with the extension cables.
That just made me picture a “U-Controll” model plane… “Highly efficient within a certain radius…”
In trying to work the math out for this in the form of a drone, I’ve found it akin to designing a perpetual motion machine. It appears to be one of those engineering fantasy’s I like to put myself to sleep with. Which is destroyed by the math..
Ditch the whole flying and go directly to teleportation – ‘theorethically possible’ according to some…
I vote Kaku be the first test speciman for the process.
Methinks Werner Heisenberg might disagree.
That’s what the Heisenberg compensator is for.
As soon as I saw the photo, I thought, “That’s Kuku!”
The same irrational thinking is rampant in the auto industry, however, there are signs of some fact based plain speak. See:http://www.detroitnews.com/story/business/autos/detroit-auto-show/2018/01/15/fiat-chrysler-ceo-says-electric-cars-are-bad-bet/109467370/
There might actually be a market for this type of aircraft as a toy for the super-rich. There are undoubtedly quite a few celebrities who would love to be able to claim that the fly an electric plane, even though 95% of the time it is just an expensive low-performance turbine aircraft
A series hybrid approach like locomotives might make some sense. Two electric motors for redundancy powering the plane while the electric motors are powered by a smaller than normal ICE engine with a small battery to supplement for extra needs for take-off. The Battery could also be used as a power source in case of ICE engine failure for an emergency landing. You’d have a bit more redundancy than a single engine plane and perhaps more efficient cost per mile. My volt works as a series hybrid when not on battery and gets similar mileage to traditional hybrids in that mode (about 42 mpg). Yet I have the torque of a much bigger engine when I want as the volt battery when ’empty’ is actually at 30 percent.
I believe the 50mpg Chevy Malibu uses the same type of Volt drive train but with a much smaller battery for torque peaks and normally is in this series hybrid mode with a small ICE motor.
I wonder what the weight difference is between the Malibu hybrid battery and the volt battery is vs the weight difference between the small ICE Malibu engine and the V6 ICE engine it outperforms. That could give some guidance on if the weight of a smaller engine with a peak load battery approach is a net zero sum or a weight increase. And in the pictured design you have 2 turbofan like electric motors that would weigh way less than 2 traditional piston engines.
I guess from my perspective, I’d need to see more actual figures to see if this series hybrid approach might work. Clearly the weight of the 2 systems would be the make or break.
The inventor of the internet would also make a fine test pilot for this plane.
I am confused. The plane has two jet engines. Jets burn fuel. Where does the battery come in?
No, it has two fans turned by electric motors which are in turn driven by a battery and jet-turbine driven generator. What you see as “jet engines” are actually just fans powered instead by electric motors.
I would
think pilotless fighter planes would be a better goal.
They are called drones.
Drones are used for reconaissance and ground strikes, not as fighters. Fighter aircraft are probably the most difficult of all aircraft to automate. Remote piloting might be possible, though vulnerable to ECM, but writing a computer program with situational awareness to handle the tactics a a multiple aircraft engagement in three dimensions in real time isn’t going to happen soon.
They will still call it a drone, eventually.
There is actually a lot of interest in this area and AF Research Lab is pursuing a number of autonomous system concepts. One concept is use of autonomous “wingmen” to support manned fighters. This mitigates the need to automate all the tactical decision making since the manned flight lead is providing overall direction.
https://www.airforcetimes.com/news/your-air-force/2016/05/17/air-force-looking-at-autonomous-systems-to-aid-war-fighters/
AF already flies a lot of “drones” but they prefer to call them Remotely Piloted Aircraft or Unmanned Air Systems.
Cheers
Tty:
We already have autonomous drone fighter aircraft. They’re called “guided missiles”.
“I’ll bet the efficiency..below …” directly powering with the jet engine. You would win that bet but you wouldn’t need all th3 weight and mechanical that goes with an aero engine.
Think (but try not to think while airborne) Prius! If I were the pilot I would want the generator running from takeoff. No doubt they would make use of the “waste thrust” left over from the generator turbine.
An airplane with FANTASTICALLY heavy fuel tanks? The beauty of a liquid fueled aircraft is that it gets progressively lighter and more efficient as you go . . . . If only this money and effort were to be spent on “the Children”. God, the stupidity here is unfathomable.
Turbine engine failures are as common as common sense from Progressive Democrats and Bath Salts – Intoxicated Street People.
Indeed. Take the PT6, it now can go 2000 hrs to HSI and 6,000 hrs to Overhaul, for it to be certified for that the TBF has to be a lot more than 6,000 hrs.
They are not thinking of using those batteries that spontaneously combust when used in cars are they?
Umm, yes, I should think that Li-ion batteries will be used. Remember, it is only rarely that thermal runaways happen. Just as long as you don’t try to charge the batteries in subzero temperatures. Which by the way means that they will have to be kept warm when flying at altitude, Fortunately you can divert some of the compressed air from the turbine for heating both batteries and passengers. So you had better always keeping it running at altitude.
The electric engines have quite small losses, so does not produce much waste heat.
For airline crashes, we want far more than just rare. We want insignificant design issues. Li-Ion is a significant design issue.
I seem to recall NASA decided to go green on the foam that covered the tanks on the shuttle, that’s when much much more ‘foam shedding’ happened during launch. One of those foam piece hit a wing, and you probably can still find pieces of Columbia in Texas if you look hard.
That one, still makes me angry as they had a right to use the foam they were using and they knew the new Green Friendly foam was worse. I still want the NASA head who approved that found, shamed, maybe even charged. Because people died from Ideology where it wasn’t to be.
Same with the Challenger, launching after too much cold was a political decision to get Christy MacAuliffe in space. The minute Morton Thiokol said no, it should have been over. The top person that heard that should have also been fired or charged.
“Fortunately you can divert some of the compressed air from the turbine for heating both batteries and passengers”
On a conventional jet/turbofan engine that is called “bleed air”, and is taken from the compressor stage. For this proposed aircraft to be capable of purely electric flight it will have “ducted fan” propulsion (as commonly used on large model aircraft now). These are high power inverter controlled electric motors driving a fan just like that found on the front of any conventional engine, so there won’t be any bleed air!
“The electric engines have quite small losses, so does not produce much waste heat”
Maybe, and it could be used, but the motors and/or inverters would (probably) need liquid cooling to cope with full power climbing. So this could be a source of cabin and battery pack heating – until it’s time for descent, when the motors will be shut down until the final stages of approach. What keeps everything warm then – more precious battery power? The whole concept is preposterous…
I think air cooling would work. Liquid cooling in aircraft is a first class nuisance. It is heavy, complicated, vulnerable, requires draggy radiators and is prone to catastrophic failure through coolant loss.
Dave,
The bleed air would be taken from the jet turbine that is powering the generator. Of course that greatly reduces its power generation capability (less air into the combustion thus limiting maximum fuel dump). APUs have been used in this way for years though.
“requires draggy radiators”
If properly designed, the radiators can create thrust.
The Meredith effect is a phenomenon whereby the aerodynamic drag produced by a cooling radiator may be offset by careful design of the cooling duct such that useful thrust is produced.
https://en.wikipedia.org/wiki/Meredith_effect
hangar.
Yes, a hangar will probably be needed in winter. While you can quite safely discharge a Li-ion battery even when it is very cold you will lose a lot of capacity.
yup. heated and insulated hangar that loses all its heat when you move a plane in or out.
Not necessarily. Could plug it in with an electric heater maintaining temperature in the battery compartment.
“….would seat up to 12 passengers and be powered by two electric motors, dramatically reducing the travel time and cost of trips under 1,000 miles (1,600 km).”
Really? On what planet?
I’d like to know what mathematical gymnastics they had to do to come up with that claim.
ooh… make the batteries quick change items: open a panel, slide out the dead batteries, slide in the charged batteries just before flight. Could be made faster than refueling.
(not advocating this by the way, short of a very compact nuclear reactor powering electric motors, I can see no path forward that will make this practical)
Sliding massive batteries in and out while simultaneously carrying out conventional fuelling might have its exciting moments.
Bruce:
Their plan involves using many small airports currently mostly idle as feeders into major airports for the long distance hops. Replaces driving from Dubuque, IA to Moliine, IL and similar legs. I’m not sure how much total time they’re going to save, particilarly when the TSA gets involved at all those small airports …
Sure. And we all know that there are lots and lots of unused slots at those major airports for these small feederliners. Particularly at rush hours.
Though they may be counting on getting preferential treatment for being (bogus) fossil-free.
Some uber-rich Billionaire Liberal would still buy it just for the virtue signalling factor. Which BTW is the same reason LAPD went oand bought all those BMW EVs they don’t use.
Maybe, one day, with ‘solar skin’ and a ground based energy delivery system (microwave?) plus a little generator plus assisted ‘launch…Let’s not sell engineering short.
in the summer of 1957 I worked as a logger in Jarvis inlet, British Columbia, famous for its clear cut being one of the few mighty works of man readily visible from outer space! In an argument in camp I made the most wonderful prediction, unfortunately unrecorded. This was pre sputnik and during the time of work on long range missiles. I said that this work on missiles will lead to space travel and the first trip would be to land on the moon and return. The mess hall burst into laughter and I was the butt of many goodhearted jokes in the ensuing weeks in the camp, 8n the bush and at the poker table. They nailed me down on when: easily in all your lifetimes – even I was surprised it was 12 years later.
Since, as an engineer, I’ve been more bold than average in my faith in the field. You can guess what my prediction is on practical electric flight. There is a world of energy in a handful of dirt.
Putting a heavy weight, low energy battery on a plane must be great for reducing emissions ;)))
Btw. to provide an A380 with intercontinental range it would require a battery of about 8.000tons. I doubt one could get that airborne..
The real climate damages are from construction workers getting killed putting up or maintaining windmills, at least in MN, IO and SD while building: ice gets inside the tower and as a worker is climbing up the inside it falls and kills them.
And now, when these will start crashing….
and all the birds, bats, killed and burnt.
So the battery can take it 100 miles, and you need fossil fuel to take you another 600. You at best save 17% of fuel, but how much less efficient is your fossil fuel portion of the trip due to the weight of the battery? You might be in a net loss position.
My experience with hybrid vehicles was the overall improvement in efficiency, instead of dispersing kinetic energy to heat in the brakes it was recycled via the battery. The range of the vehicle for a tank of fuel increased (had a smaller tank therefore lower weight). So when climbing in a plane you’d be using both fuel and electricity but when descending you’d be recharging the battery. The key would be to balance the weight of the electric system with the reduction in the mass of fuel, it will be interesting to see if they can achieve it. You know that like with the hybrid car, once it’s done once everyone will be doing it. All the car companies were looking into hybrids but it was far in the future, then to everyone’s surprise Toyota produced the Prius!
I recall talking with Prof. ‘Med’ Thring about combustion efficiency in the mid-70s and he said “Yes Phil. you can improve the efficiency a little bit but you can make bigger improvements overall if you incorporate regenerative braking”. Of course then everything was mechanically controlled and carburetted and the concept of the modern computerized engine was just a dream (my data acquisition computer was a PDP8 with 4k memory!) About 30 years later it became a reality, both improved combustion efficiency and regen braking.
Phil:
Most of the improvement in hybrids comes because the IC engine uses the Atkinson cycle instead of the Otto cycle — basically the expansion ratio is higher than the compression ratio, pulling more heat and energy out of the fuel combustion. Lower power density than the Otto cycle but higher thermodynamic efficiency. The electric motor makes up for the lack of torque from the IC engine for burst demand. I have a Toyota Avalon hybrid and love it. I get 650+ miles to a full tank at 39 MPG and give up nothing for it other than some trunk space.
I’m not sure that you will gain much on the descent. Conventional aircraft use flight idle power during the descent and so regain a fair proportion of their energy of position as range in what is really a powered glide. This aircraft supposedly will stop the turbine engine during descent and windmill the fans to recharge the battery. However power for avionics, cabine pressurization and heating and hydraulics will still be needed so the net may not be that big. Windmilling engines will also mean more drag and therefore a shorter and steeper descent than a conventional aircraft (which might not sit well with ground control). Once you get close to the airport, start maneuvring and go into a high-lift configuration, turbine engine restart and full power is of course needed. A failed re-start would be a serious emergency.
Me, I would rather feather the fans to minimize drag, run the turbine at flight idle for auxiliary power and to recharge batteries and do a conventional descent. Safer and probably not much less efficient.
But the regeneration phase really doesn’t accomplish anything except save on the recharge time when you land. In terms of fossil fuel use it saves you nothing.
This hybrid BizJet is sorta like Moonbeam’s High Speed Choo-Choo from Fresno to Bakersfield. It may kinda work, but who would need it? or want to deal with the many logistical problems of using it?
And then there is this:-
http://www.rolls-royce.com/media/press-releases/yr-2017/28-11-2017-airbus-rr-and-siemens-team-up-for-electric-future.aspx
I rather doubt this will end up in Jay Leno’s garage.
https://youtu.be/Vr3dX2EClDg
Very nice music. Reminds me of a funeral march.
Curious George: “Very.nice music.”
I’ve never been to a funeral march so can’t relate. Was there some point besides your musical preferences?
This is not a passenger plane. It is a glorified glider. Do you have data on glider safety?
“Do you have data on glider safety?”
Do you? Safety wasn’t the point in posting the video. The video shows these airplanes traveling a considerable distance to a specific destination, landing safely, taking off under their own power, and returning to their start point. That isn’t something an unpowered glider can do.
Many glider accidents (and, yes, it can be dangerous, especially since glider pilots don’t necessarily have much training) occur when towing the glider to get it airborne.
Given a suitable landing area, any winged aircraft can land without power. When landing, the space shuttle–a “passenger plane”–was also a “glorified glider.”
This thread is about a mass-production of electric planes. We can probably agree that gliders are not the way to go.
Some thermal power was involved too no doubt.
These look like powered gliders, so I suppose the flights could have been planned to take advantage of thermals in the Alps.
Electric does not necessarily mean battery-powered. Fuel cells are not yet quite there, but they hold a great promise – much better fuel efficiency compared to internal combustion engines. A fuel cell breathes air, while a battery has to carry an equivalent of oxygen inside, making it much heavier.
Fuel cells technically only work with hydrogen. Methane ones strip the hydrogen from the carbon before processing the fuel. I don’t believe they work effectively with complex.liquid fuels – like jet fuel. Jet fuel isn’t like gasoline either where there is basically one octane molecule in the mix. Jet fuel is a collection of multisized carbon chains that in agregate exibit certain characteristics – so I imagine it would be hard to tune some catelist to strip the hydrogen.
My dream is a fuel cell powered by C2H5OH.
Sadly, there are significant engineering problems before we have reliable fuel cells. But once solved, that will change the game.
What happened to propane fuel cells? Are they currently too inefficient?
How do federal subsidies for fuel cell research compare with federal subsidies for climate catastrophe warnings?
Answering my own question, propane fuel cells are being used in UAVs by the U.S. military:
“The high energy density of propane results in a significant tactical advantage for the D350 relative to rechargeable batteries. Example: 11 BB-2590 batteries weighing 25 pounds will produce 2.2kWh of energy, while a D350 and 13 pounds of propane, also weighing 25 pounds, will produce 13kWh of energy!”
https://www.ultra-fuelcells.com/Products
Time to remember the Aircraft Nuclear Propulsion (ANP) program (1946) and reconsider Thorium powered flight?
Toto:
How many rural runways could handle the weight of a nuclear powered aircraft? Could the cost be recouped from pissant fares for what is basically an airborne taxi ride?
Given cheap electricity and short hops, it’s possible inexpensive-to-build-and-maintain electric-motored “glorified gliders” could be economically feasible and safer than traveling public roadways.
Here’s your practical Green power source for aircraft: pedal power!
http://vintagesodamachines.com/PedalCar/Airplane_Corsair.jpg
Has also been tried, many times, but with rather limited success:
If you really want to improve aircraft fuel efficiency then the Unducted Fan (UDF) “Propfan” engine is the way to go. There was a fair amount of development work done whe oil prices were high back in the eighties, but it was discontinued when fuel prices dropped back. An UDF engine can have at least 30% better fuel efficiency than a turbofan. It has drawbacks of course, it is noisy, there is more vibration on board and last but not least, it seems quite impossible to convince the public that aircraft with “propellers” aren’t old and dangerous.
The simple way to reduce emissions is to ban air travel.
Why is this never suggested? Environmentalists are among the heaviest users of airlines and the biggest polluters.
In Sweden this is a favorite demand of the greenies, everybody is to travel by railway (except possibly politicians and environmentalists). However in country the size of the USA it is probably too obviously impractical even for greenies. For one thing a railway to Hawaii will probably be rather expensive.
Jerry Brown just might propose it …
Carrying the weight of a battery for a long flight makes even less sense if you have to also lug along the weight of fuel plus an FF engine in case the battery runs out.
However, I could see electric powered hover craft being used for local emergency medical flights. It would shave off the time needed to start up a turbine or IC engine and eliminate the need to travel to a nearby airport for refueling, (assuming battery packs can be charged and swapped out on the roof of a hospital).
Something like …
One huge problem with this idea: Conventionally-fueled aircraft burn off their fuel as they travel, thus reducing the gross weight of the aircraft and becoming more efficient over the course of the flight as weight decreases. Commercial aircraft also tend to have landing gear that is stressed only for takeoff at max gross weight (with full fuel), but not for landing at that weight (thus why aircraft that make emergency returns to the departure airport usually burn off fuel first, or dump it if they have that capability installed).
A battery-powered aircraft would have to carry the full weight of its “fuel”, the batteries, all the time. And that’s not to mention hybrid configurations, as in this article, that would have to carry batteries, an alternate APU, and jet fuel for the APU. The fact that the gross weight would therefore never change, at least in a pure electric aircraft, means that the aircraft is always having to generate extra lift to carry the extra weight, which is very inefficient. It also means that the landing gear has to be designed to withstand landing at max gross weight without collapsing, which requires the gear to be stronger and thus heavier, further decreasing efficiency.
That’s all another way of saying, “This is a really stupid idea.”
“A battery-powered aircraft would have to carry the full weight of its “fuel””
Not necessarily, you could have it running on small batteries that only run a short time then throw the expended ones out the window as you go. Don’t laugh, birds poop in flight. 🙂
http://autovolts.com/wp-content/uploads/2016/04/SNL-mercedes-AA-class-duracel-battery-ad-julia-louis-dreyfus-3-1.jpg
Good thinking. Might even be able to build recycling centers along air routes, and hire people to drive around with metal detectors collecting the spent batteries for recycling. Just imagine all the new green jobs!
“Recycling ponds.” See above.
I expand on your comment below.
This can’t improve efficiency like a hybrid can – by recovering energy lost thru braking,
so the question becomes: where is the efficiency/cost gain? Perhaps electric motors, which last forever and require no maintenance, is where the efficiency comes from. But they state that the range extender power generator is a jet engine. More knowledge required – there must be some reason for doing this. I’m guessing it’s in the use of electric motors to drive the fans.
The inmates are in charge of the institution.
Do the math: Gulfstream G450 11 passengers total Horsepower = 42,615.38 @500kn
Where is the 6,620 pound electric motor that can produce that horsepower rating? For the 5,000 mile range there is 29,500 pounds of fuel, for 1,000 miles make that 5,900 pounds.
And just how much do the batteries weigh?
And this thing will need fuel to power a real engine to keep the batteries charged?
A lot of extra weight.
Someone upthread mentioned hybrid cars being useful for intercity driving because of all the stopping and starting.
Is that what you want for a plane?
If some want to invest their own money (no taxpayer cash) to develop this plane, fine. Have at it.
I hope you make a million. Just don’t use the taxpayers’ billion to do so.
Take two aspirin and call me when they get 130K BTU batteries in the volume and weight of a gallon of fuel.
Liquid hydrogen is best choice. That is why military using it for drones. Much longer fly time.
Liquid hydrogen has very low energy content per volume unit. A long-range hydrogen powered aircraft would have to be extremely large, several times bigger than a 747 or A380.
Issue of takeoff and landing weight is critical. Beauty of combustion engine is that fuel mass is consumed without residue, aircraft gets lighter as it goes, aircraft becomes more efficient with every shed pound, and landing weight is much less than takeoff weight. Batteries do not get lighter as they discharge. Electric aircraft design is thus limited by landing weight unless batteries are going to be jettisoned. Making a hybrid propulsion system just consumes more of the weight budget with duplicative and unnecessarily complex machinery.
The right place for electric is for distributed propulsion for VTOL. I think it is possible to build a small two seat VTOL aircraft that uses a piston engine for forward flight and a electric motors driven by alternator on the engine for VTOL with backup batteries if the piston fails.
Making it as an Experimental homebuilt avoids a bunch of regulatory issues.
I would say “between +12 and -12.”
Is it 100 miles, downhill, with a tailwind or somewhere there are zero air currents, no air temp changes, and completely flat terrain? Does it change to 10 miles under…um…normal weather conditions?
AND, after 100 miles, when the gas fueled engine kicks in, does that engine do double duty and fly the plane WHILE charging the batteries, or does the plane just “glide” until the batteries are full again?
Are Boeing and JetBlue headquartered in legalized marijuana states? Just curious…
Have drop batteries with wings, on the aircraft wings and once cruising altitude is reached, or take-off is complete, drop the batteries and let them glide back to the charging point.