Electric Airplane Developments
 

I see that another new electric airplane has flown! The eKUB Microlight took flight the other day. This is wonderful news, as this technology is going to form the basis for at least some general aviation in the future. It's a steep hill to climb, not only for the development itself, but for the path to certification as well. We GA pilots need to embrace this technology as much as we can, it will become a part of what keeps general aviation alive!

I spoke to a chap the other day who instructs on a Velis (?) the electric cousin of the Virus SW. They even let students solo on the electric thingy. Range is limited to around 200 kilometers with careful treatment but only half of it is used. Good for pattern work and a 50 NM XC will work too. But you need to have industrial grade power connectors to charge it via some clumsy box. Not bad but not there yet.

I heard that Pipistrel has been bought (or will be) by Textron, so perhaps that will provide a boost to the electric aircraft business (https://www.pipistrel-aircraft.com/151027-2/).

Very nice aircraft, elegant and with some spacious cockpit. Must make for some perfect personal airplane. I would still prefer the Rotax version at this time.

Until they have at least 4 to 5 hours endurance, or 5 to 10 minute charging at all the fields we use, they just won't work for our operation. We don't let students airborne with less than half tanks.

They switch to combustion versions for everything outside the pattern. In the pattern students might fly solo on electric power.

Then the runway gets blocked by the aircraft in front and they have to divert. We do the same as MrAverage, min 2 hours endurance at planned end of flight for solo students.

It'll come and all power to the efforts of people like Deepak.

TOO

So impractical for many GA users, especially at the lighter end. I'll be waiting for the electric version of the gerrycan

Or something like this:
https://www.studyfinds.org/power-bea...gy-from-space/
Microwaves to transfer electric energy. It can even be done from space so no need for a battery and unlimited range.

Until someone does Ctrl-Alt-Del by mistake.:E

CG

Electric will solve so many problems. Installing charging points is cheap and requires little complication and regulation. Petrol/Jet A! installations are complicated, costly and subject to a lot of expensive regulation. Electric charging allows several charging points to be installed for plug in and walk away, at every parking stand if you wish. Hydrocarbon fuels stations are limiting so often means time consuming ques and aircraft repositioning otherwise or long waits for the bowser.


Electric engines give a high torque which is perfect for propellers and are low in maintenance. Fuel is the largest part of the current operating cost and comes with a high weight penalty. Batteries will come with low cost, enormous benefits both in mass and endurance. The technology is rapidly developing because its in the interest of all vehicles and machinery and is spurred on by the worldwide environment concerns. Shouldn't be too long before battery power is the norm for our aeroplanes.

I have to totally disagree. Battery aircraft are clearly not the way to go. Except for small ones. Possibly liquid hydrogen can do the trick for airliners - that is if all the energy needed can be made "green". Otherwise aviation will be more like the final thing to move away from kerosene because it is low weight given the energy stored, liquid and won't be carried as empty battery dead weight on every single touchdown.

I had previously been hire to work on certification of an electric conversion for a 172. We got a long way down the path, but the ultimate problem was going to be down time for charging. There are commercial realities of using an airplane for 45 minutes, and then having it off line for several hours to charge. For a private airplane, where the owner wants to fly 45 minutes a day, it would have been perfect - but that's a lesser market right now.

The electric conversion project I'm currently involved in recognizes this operational reality, and is planning to account for it - for now - while they wait improving battery technology. It'll come, and some very forward thinking aviation entrepreneurs are working to create a market. There are other certification [regulatory] adjustments to be made, though I find that the regulators are very receptive.

Last summer, I was playing Frisbee at a sports field that's adjacent to Paine Field (Everett) when I noticed an unusual aircraft flying overhead - basically looked like a powered sailplane, but no discernable engine noise, just a drone like hum. It circled around the area for perhaps half an hour before leaving. Reasonable sure it was an electric aircraft - probably doing some testing. Staying close to the airport meant that if something went wrong it could easily glide in for a dead stick at the airport.

Sort of an intriguing idea - an electric sailplane that could takeoff on it's own power, find a good area of thermals and shutdown the electric motor and glide for a while, then return to the airport using the electric motor if necessary to extend the range.

Battery chemistry/density and charging technology hasn’t been arbitrarily fixed on some day two years ago. As ever we are too impatient for progress to suddenly leap to our rescue instead of carefully monitoring and supporting developments that will take years to achieve.
At some stage in the future - lead by automotive research - you will get the range and quick recharge to replace the C150 etc. that will satisfy most missions.

No-good predicting a date - it’s in the future but will get here eventually….

More than an intriguing idea - they have been been manufactured for many years. Try a search for "Antares 20E" (first flight 2003) and "Pipistrel Taurus" which are both self launching. There are other electric "sustainers" such as "FES" that do not have the power to self launch but can get off the ground with a low cost auto tow and then climb on the sustainer.

Another facility offered by batteries is to be exchanged, taking minutes, by the pilot. If so it won't be necessary to wait whilst the batteries are recharged.

It'll be a while before changing batteries is practical, let alone a pilot task. Handling a few hundred pounds of batteries around an airplane will require a special lift machine, which sure, is doable, and then immense care not to dent the plane with it. If the replaceable battery pack is inside the cabin, it is a handling problem, and its being properly restrained is critical. If a belly pod, assuring it's correctly attached will be important. If in the wings, where the fuel was, not easy to change. Cessna 150/152/170 have dozens of screws, all the larger Cessnas have inaccessible tank areas from the perspective of installing batteries. This was the main stumbling block for the electric 172 project I was working on for a while - batteries are there to stay from a day to day operations perspective.

Of course, new fuselage designs will get around this, but in most cases, that will mean a new plane. New planes are costly, for a private market who sometimes struggle with the cost of the legacy types.

The Pipistrel Alpha Electro was designed to have its batteries replaced between flights, but I understand that the stumbling block is that this proces is seen as a maintenance task.

Batteries are rapidly getting smaller and the capacity increasing. Innovation is reducing the demands on the battery and together all this will increase the endurance. This is no different with electric cars and so that industry will innovate. It has the resources to do so.

The old wisdom of 'don't repair old clothes with new cloth' is true. Retro fits rarely work: beset with problems and expensive. It is a whole package that will bring about change.

There was a fleet of thirty electrically driven taxis in Amsterdam around 1910 (out of a total of 240 registered cars). Back then the expectation was that electrically powered vehicles were the future. Look how far we've come since then....

The first Porsche: Electric but two tonnes of weight.
https://newsroom.porsche.com/en/prod...ory-18563.html

Which dramatically increases the energy density and with it the danger.

Jan Olieslagers Energy density does not necessarily = danger...

However, as most clearly realise, with conventional electric transportation it's the energy density of the supply that's the limiting factor at present.

What brings things into perspective is a comparison of the best portable electric source (let's say a Lithium-ion battery) against a unit of petroleum. If we use Joules per kilogram we find that 1kg of petrol has ~44MJ/kg, a Li-ion battery has ~0.6MJ/kg, give or take. Thus conventional fuel typically contains around 70 times the energy per kilo than electric.

This is offset to some extent by the relative efficiency of converting this energy into power that will propel your 'plane. It's a complex field, but for the purposes of a simple comparison let's assign an efficiency of 90% to electric, and 30% to a combustion motor.

However, while the electric system has much greater efficiency, from a practical perspective it clearly remains overwhelmed by the vastly superior energy density of petroleum.

So, there have been significant advances in (electric) energy storage over the past 20-30 years but, unless there is a 'eureka' moment, I feel it will be quite a long time before it becomes fully viable and comparable to 'conventional' fuel-powered aircraft.

FP.

Yes Jan, but then petroleum products burn and fuel tanks explode. Fatal Carbon Monoxide poisoning is also all too common. First Principal outlines neatly where we are.

The development of electric vehicles is dependant on more than only the battery. As for how rapid things will develop, nothing before has stimulated the need more than the environmental concerns of today.

Without major advances in battery technology which is unlikely to happen soon the energy/weight factor makes practical endurance/range aircraft impractical.
Hydrogen is a lot more promising but will need a very expensive refueling infrastructure. There are also questions about carbon neutral production of hydrogen, this would need a lot of green electricity.
There is a lot of work going on to solve the problems, my best guess is that light aircraft will use electric motors powered by hydrogen fuel cells.
All of this is unlikely to happen very quickly for light aircraft which have a service life of 40+ years so there will be no rush to replace these expensive assets with new technology. Avgas will be with us for decades more.

Is true. Though the economy of Avgas may leave us. As the cost of fuel makes flying prohibitive for many pilots, they fly less, which results in reduced pilot currency. In an airline environment, simulators can make up a lot of this, but for GA, we're going to need a modest cost means to keep pilots, particular less experienced pilots, in the air. Electric planes will not fly far or for long, but if they keep GA pilots current, that's something....

Having passed my three score years and ten little to nothing of the past feels that far away. I bought my first mobile in 1992. I say bought but you rarely did because they cost then £2000 or $3000 dollars so you rented on a lengthy contract. The phone was the size of a ladies handbag. the battery would hardly last more than a couple of hours of use so I had four. Each battery was the size of a machine gun cartridge. The telephone did one thing: make and receive telephone calls. Today, my mobile slips into my shirt breast pocket and has the facility of a powerful computer. The battery is tiny and will last all day if not two. There is very little it can't do including being a high definition camera and act as a comprehensive GPS; both for aviation and with road moving charts/maps for navigation. For road use the software can be free with apps such as Waze. All this is for a few hundred pounds.

So, for me, 20 - 30 years ahead is no time at all, its if it was tomorrow. Avgas is already struggling to survive as petrol is required less and and in some parts of the world impossible to buy. It may not be the case that Avgas is only expensive then, in the foreseeable future, but it could prove difficult to obtain irrespective of price. Mineral oils already are only available because of the total loss demand of the food processing industry. Oil producers don't see their future in petroleum products. They would stop making avgas and mineral oils tomorrow if they could.

I'm not so sure there. I'll readily agree that "fossil fuels" in general will be available for quite a while - longer than my lifetime, sure enough. But fossil fuels ARE on the way out, and AvGas being a rather rare variety it will be among the first to go. MoGas will stay a bit longer, especially if alcohol-doped; diesel/kerosene much longer, because a lot of commercial transport depends on it.

Oh yes, it does. The question is: to what degree is the danger known and addressed and controlled? Surely fossil liquid fuels have their own dangers, and accidents can and do happen, but the risks are known and there are procedures to deal with issues. With batteries, much of that knowledge still needs to be built up. For one example, fire brigades are recently learning that a car with a burning battery can only be extinguished by immersing it in a tub full of water, and such tubs are now being constructed here and there. How to deal with the same condition in your SEE is yet to be determined.

"Avgas will be with us for decades more."
Who are "us"? There is talk of big oil/gas development by Eastern nation organisations in the Kurile Islands region. Not everyone is going "carbon neutral".

Published in Avweb today;"Diamond Aircraft says the electrified version of its DA40 single will have up to a 90-minute endurance and charge time of 20 minutes. The company announced on Wednesday it has chosen Safran’s ENGINeUS electric motor to power the eDA40. “With Safran we are having an expert partner for electric propulsion systems aboard,” said Liqun (Frank) Zhang, CEO, Diamond Aircraft Industries Austria. “The smart motor’s state-of-the-art technology including smart features paired with a well-advanced certification process is the logical choice for our eDA40. We are looking forward to the first flights scheduled for end 2022.”

Diamond announced the program last October. The aircraft is aimed at the training market and Diamond is predicting a 40 percent decrease in operating costs for flight schools. The 90-minute endurance likely won’t be achieved immediately but will be possible as battery technology evolves. Diamond is predicting certification for the motor by mid-2023 and basic EASA certification of the aircraft in late 2023 or early 2024."

So perhaps we won't be waiting as long some doubters believe

There are totally new aspects to think about, battery health one of the most prominent. Like charging software, charging power used and peak power use, battery temperature, environmental temperatures in cruise flight, battery aging. It will take a while until this is good enough for Joe public.

Precisely. On the long term, fossil fuels are dead, and batteries are today the only realistic alternative. Still, they are far from being "market-ripe".

To me it seems rather that we will wait longer than some hopers believe. Especially in the very conservative environment of aviation in general, and private aviation in particular.

This company thinks differently:

Massachusetts-based commuter airline Cape Air has signed a letter of intent (LOI) with Eviation for the purchase of 75 all-electric Alice aircraft. The terms of the agreement have not been made public. As previously reported by AVweb, Eviation announced in June 2019 that Cape Air would be its first commercial customer for the aircraft, which is still in development.

“Truly sustainable aviation not only reduces the impact of air travel on the environment but also makes business sense,” said Jessica Pruss, Eviation vice president of sales. “We are proud to support Cape Air, a recognized leader in regional air travel, to chart a new path in delivering innovative solutions that benefit airline operators, passengers, communities and society.”

Cape Air currently flies more than 400 flights a day to locations in the Northeast, Midwest, Montana and the Caribbean. According to Eviation, the Alice will have a top cruise speed of 250 knots, maximum payload of 2,500 pounds and single-charge range of 440 NM. The aircraft will seat nine passengers and two crew members and is powered by the magniX magni650 electric propulsion unit. Eviation noted last February amidst a leadership change that it was expecting to fly the Alice for the first time “in the upcoming weeks.”

Excuse me for being unimpressed. A letter of Intent is not an order, not by a long way. How could it? This Alice thing has not yet flown (except as a scale model), to not even mention certification. Baked air has a fine scent, admittedly, still you shouldn't be led by the nose.

https://insideevs.com/news/583324/pa...ter-two-fires/
No idea what has caused this but perhaps these quick change aircraft batteries should also be ejectable. 😁

Today's Telegraph has a piece on the Sherwood E Kub having flown for a thirty-minute flight over Norfolk.. .. smart looking aircraft, except for the upside-down depiction of the Union Jack.:</

Excellent. I believe that the pilot contributes here from time to time, I hope he'll tell us a little about this project when the time is correct for that...

Fossil fuels are not dead. The post globalisation world will see to that. By the time legacy fossil fuels are getting difficult to extract there will be a range of synthetic liquid fuels on the market. Crude oil can be made from algae, or from thin air. Liquid hydrocarbon fuels and internal combustion engines will be around for a very long time.