back to article EU aviation wonks give all-electric training aeroplane the green light – but noob pilots only have 50 mins before they have to land it

The EU Aviation Safety Agency (EASA) has certified its first all-electric aeroplane for routine use, marking a small but significant step on the route to all-electric airliners. "This is an exciting breakthrough," said EASA executive director Patrick Ky in a canned statement as he boasted about the Pipistrel Velis Electro …

  1. Egghead & Boffin

    Waiting for the oil temperature to rise really isn't a big deal, if at all. I have a PPL and I don't think I have ever had to wait for the oil temp to rise before take off. By the time one has started the engine, done the checks, radio checks and taxied the oi temp is ok well before one calls for take off from the taxiway holding point.

    1. John Sager

      Yup. And having gone the PPL route decades ago, part of training is how to manage the engine - magnetos, revs, mixture, carb heat etc. None of this on an electric trainer so type conversion is going to be more than just a quick trip up with an instructor in the small Cessna or Piper.

      I will continue to laugh at electric aircraft, until battery tech gets much better. The concept makes range & payload figures look stupid.

      1. Anonymous Coward
        Anonymous Coward

        Well the whole piston engine magneto/mixture arcana is great if you are going PPL - a bit of a red herring if you are going to transition to an Airbus. While 'it ain't broke don't fix it' is a reasonable mantar for something dangerous like flying the Cessnas and Pipers of this world are basically using 1930s technology. There's a wide range of modern light and ultralight aircraft with modern engines (fuel injected, electronic ignition etc) and digital cockpit instrumentation.

        1. werdsmith Silver badge

          The PPL training fleet is gradually being replaced by the modern machines, but there was something a bit charming about fiddling with carb heat and mixture. Although I do like the security offered by a BRS parachute and would enjoy going places in something like an SR22, all my hours for the last 4 years have been on a Super Cub purely for its charm and flying for pleasure appeal. If I could afford to fly a DH82 then I would.

          I can't help thinking that the case for an electric engine would be a motor glider, could get away with a 10 minute battery.

          1. Zolko

            @werdsmith : "on a Super Cub purely for its charm and flying for pleasure appeal"

            then you should try to fly gliders (or better: hang-gliders): the joy of feeling the air around you, playing with the winds, looking for clouds ...

            1. John Brown (no body) Silver badge

              "the joy of feeling the air around you"

              It's cheaper just to buy a kilt :-)

        2. ICL1900-G3

          Sadly for the aero industry, and speaking as a PPL, I don't think there will be a shortage of commercial pilots for a good few years.

        3. Alan Brown Silver badge

          "the Cessnas and Pipers of this world are basically using 1930s technology."

          For the simple reason that piston engines were largely abandoned for aeromotive use about then. Light/ultralights tend to be on Sport/experimental licencing rather than GA, which heavily restricts what you can do with them

          surprisngly it wasn't engines which was their undoing - What _really_ killed GA for the most part was litigation-happiness in the USA - airframers suffered the death of a billion papercuts because families of people killed in GA crashes sued everyone possibly involved. Even fighting off vexatious litigation is expensive

      2. John Brown (no body) Silver badge

        " part of training is how to manage the engine - magnetos, revs, mixture, carb heat etc."

        Someone described that to me as having to learn how to manually operate a vintage car with all it's arcane controls like manual ignition timing and fuel mixture controls and stuff to pass a test so you drive a modern car.

        Yes, I do understand that in the world of light aviation there still a large number "Ford Model Ts" still operating.

  2. Steve Foster

    Boost from Solar?

    Can't tell from the picture, but as this is primarily aimed at training and therefore probably mostly daytime flight, it seems like an obvious opportunity to cover the upper wing surfaces with solar panels to boost capacity/range.

    1. Anonymous Coward Silver badge
      Boffin

      Re: Boost from Solar?

      A lot of expense and a bit of added weight and complexity, for at most 2kW boost. That's less than 10% of the battery capacity (for 1 hour), so could maybe extend that 50 minutes to 55 minutes. I doubt it would be worth it.

      Covering the airfield/buildings in solar panels to charge the planes on the ground however...

    2. Richard 12 Silver badge

      Re: Boost from Solar?

      By how much?

      Rounding up, 1 hour endurance with 25kWh means 25kW mean consumption.

      Solar panel is around 150W/m^2 output in good conditions, so each square metre of solar panel provides 0.6% of the energy required to fly.

      So solar panels would extend the endurance by 21 seconds per square metre, in good conditions.

    3. Anonymous Coward
      Anonymous Coward

      Re: Boost from Solar?

      "it seems like an obvious opportunity to cover the upper wing surfaces with solar panels to boost capacity/range."

      If the design change could be done with a zero mass budget and without affecting drag, you could probably fit ~6.0 metres square of solar panels on the wings. Assuming *state of the art* solar cell efficiency, you'll get perhaps 30% of 1KW per metre squared on a cloudless day assuming the sun is directly overhead, so ~2kW of extra power. i.e less than a 10% increase in endurance before accounting for any of the downsides of the solar installation.

      However, you can't add solar cells at a zero mass, and you also need to allow some more for the cabling, and then a few kilos on top for some circuitry to match the voltage from the solar cells to your battery pack and add some safety cutouts etc, so the net increase in endurance will be less, because you'll have a higher take-off weight, requiring more energy to be used.

    4. Anonymous Coward
      Anonymous Coward

      Re: Boost from Solar?

      Nah, with all that wind whistling by they should fit wind turbines

      1. Evil_Goblin

        Re: Boost from Solar?

        Re-generative props? :D

        Climb up to altitude, throw a suitable hefty switch to switch your electric drivetrain into charge mode, then dive for all your worth, pull up into zoom, throw switch again to get power back up to altitude. Rinse and repeat... Sick bags provided...

        joke obvs, just in case...

      2. werdsmith Silver badge

        Re: Boost from Solar?

        Wind power is how some gyro-driven cabin instruments are powered on older planes and many vintage planes still flying. With venturi horn in the airflow on the outside of the plane.

  3. Anonymous Coward
    Anonymous Coward

    Does it have regenerative braking?

    Does it have regenerative braking?

    (twice, for redundancy)

    1. Yet Another Anonymous coward Silver badge

      Re: Does it have regenerative braking?

      There is an optional wind turbine to charge the battery

      1. hoopsa

        Re: Does it have regenerative braking?

        Is that the windmill thing on the front of it?

        1. Smooth Newt Silver badge
          Trollface

          Re: Does it have regenerative braking?

          Is that the windmill thing on the front of it?

          No, that's just a fan to keep the pilot cool. You should see how much he starts sweating if it stops turning.

      2. Anonymous Coward
        Anonymous Coward

        Re: Does it have regenerative braking?

        "There is an optional wind turbine to charge the battery"

        RATs to that idea!! (Ram Air Turbines, for those who don't know, are generally pop-out windmills used on aircraft when the power fails - it can mean the difference between landing safely and leaving a big hole in the ground).

  4. GlenP Silver badge

    Can't Wait

    I hope the flying schools at my local airport have some on order. It gets blooming noisy here on training days (I'm about 300 yards off the end of the runway and pretty much in line with it).

    1. redpawn Silver badge

      Re: Can't Wait

      Perfect location for land straight ahead on takeoff engine failure.

      1. Steve K Silver badge

        Re: Can't Wait

        Quite - if GlenP leaves his landing light on then even better!

    2. RM Myers Silver badge
      Happy

      Re: Can't Wait

      I live about 2 miles from a very busy non-commercial airport, and this would definitely help the noise level here. Unfortunately, the airport also handles a number of small jets which make more noise than the training flights.

      There was one exception to the "non-commercial" part when a pilot managed to land a Boeing 707 at the airport by mistake. Given the runway was only about half the normal length a 707 needs, getting it out of the airport has become the stuff of local legend. TWA basically had to strip the plane's interior to reduce the weight.

      1. Phil O'Sophical Silver badge

        Re: Can't Wait

        There was one exception to the "non-commercial" part when a pilot managed to land a Boeing 707 at the airport by mistake. Given the runway was only about half the normal length a 707 needs, getting it out of the airport has become the stuff of local legend.

        Dan Air (locally known as "Dan Dare") once landed an incoming Belfast flight at a nearby disused WW2 airfield. It caused much consternation for the control tower when the pilot announced they had landed, and the tower replied "we can't see you". According to local rumour the pilot wanted to turn round & 'hop' to the main airfield, and was told in no uncertain terms that he wasn't taking off with passengers from an airstrip with no safety equipment. The airport sent a bus instead.

    3. werdsmith Silver badge

      Re: Can't Wait

      I hope the flying schools at my local airport have some on order. It gets blooming noisy here on training days (I'm about 300 yards off the end of the runway and pretty much in line with it).

      EFATO

    4. Alan Brown Silver badge

      Re: Can't Wait

      " It gets blooming noisy here on training days "

      Combatting this is one of the primary aims of electric trainers.

      The fact that those vintage technology Lycoming engines need servicing every 50 hours and tearing down to the last nut and bolt every 5000 hours makes them _extremely_ expensive propositions.

      For training aircraft like a Piper Tomahawk, when soloing fuel is only about 20% of the overall operating cost. The labour costs of the engine and wings eat up 90% of the rest.

      Even if an electric trainer needed to be recharged on the ground for 2 hours to get 50 minutes flying it would be a viable proposition to have 3 of them vs one conventional trainer. Longer endurance is needed for longer stuff but 50 minutes is a good duration for circuits and suchlike. I can see tradeoffs being advanced - putting more batteries in to give greater endurance at cost of restricting operation to single seat use due to MTOW/MROC limits (The Tomahawk is a good example of tradeoffs: It's cheap and only has a 110hp engine. You _cannot_ get off the ground with two average sized adults, full fuel and more than an overnight bag as baggage, but I've used it for 300 mile solo weekends away, lugging a reasonable amount of junk between family members whilst doing so)

  5. David Pearce

    Reserve power?

    Only 50 minutes and it would be a very bad idea to be airborne with less than 30 minutes power in reserve in case you have to circle or fly to another airfield

    1. Totally not a Cylon
      Joke

      Re: Reserve power?

      Can of Redbull?

    2. Captain Scarlet Silver badge

      Re: Reserve power?

      I assume they will have to take that into account, are they that slow that they wouldn't make another airport within 5 minutes for an emergency landing?

      1. nobody1111

        Re: Reserve power?

        "...are they that slow that they wouldn't make another airport within 5 minutes for an emergency landing?"

        Erm, yes? Most GA aircraft are. You are generally flying at 100 kts or less. So 5 minutes is around 8nm.

        These aircraft are a good way to practice touch and goes. Which are a high percentage of training time. Fuel and engine maintenance savings should lower operative costs by around 25-33%. So a material benefit. But replace a piston single for training? Nope.

        Oh, and Register? "...marking a small but significant step on the route to all-electric airliners." Yeah, right. Batteries have nowhere near the energy density of gasoline much less fuel oils. Wasn't there some scam recently where somebody tried selling some ignorant managers that a diesel electric airliner was possible? Then after spending quite a bit of money they invited an engineer to actually run the numbers. Project cancelled and everyone ordered to not talk about it.

        1. Anonymous Coward
          Anonymous Coward

          Re: Reserve power?

          " "...marking a small but significant step on the route to all-electric airliners." Yeah right"

          I think this slightly earlier article may be enlightening (it's even referenced in this article):

          https://www.theregister.com/2020/04/27/airbus_rolls_hybrid_plane_grounded/

          Derby lost the plot several years ago, doubtless contributing to the 10,000 or so redundancies at RR announced in recent months..

        2. rcxb Silver badge

          Re: Reserve power?

          Batteries have nowhere near the energy density of gasoline much less fuel oils.

          Lithium-Air batteries have a theoretical specific power of 11.4 kW/kg, compared to the theoretical maximum of 11.99 kWh/kg for Jet A-1, so very close.

          We don't have theoretical batteries, you may say, but that's fine, because we don't have theoretical engines with 100% conversion efficiency for jet fuel, either. And if we did, they wouldn't be zero mass and zero volume, so would negatively affect those numbers. And that's without mentioning that jet fuel needs things like storage tanks, pumps, which also add mass and volume.

          Your argument sounded less foolish years ago, before electric vehicles like the Teslas came along and proved it's possible to get the same range with batteries as with gasoline for only modestly more weight. Battery technology is not static, manufacturers continue to increase energy densities. In time, they absolutely will become competitive, it's just a gradual process.

          1. SteveastroUk

            Re: Reserve power?

            Has an airliner ever been designed that lands at its takeoff weight ?

            1. chrisw67

              Re: Reserve power?

              None that I am aware of... but then they have not had to design the airframe that way. A Boeing 737-800 is approx MTOW 79000 kg and MLW 63500 kg. Retrofitting electric engines in an airframe like this, if at all possible, would have to stay below the MLW at takeoff.

            2. Anonymous Coward
              Anonymous Coward

              Re: Reserve power?

              Yes - loads of them - a VC-10 for instance. With modern aircraft anything designed for short haul will not be far off, as obviously you won't have burned a lot of fuel by the time you are going to land. Many twin engine turboprops with less than 100 seats, and all single engined aircraft (not many 'airliners' in that category - but a few commuter style planes like the Cessna Caravan).

          2. juice Silver badge

            Re: Reserve power?

            > Your argument sounded less foolish years ago, before electric vehicles like the Teslas came along and proved it's possible to get the same range with batteries as with gasoline for only modestly more weight. Battery technology is not static, manufacturers continue to increase energy densities. In time, they absolutely will become competitive, it's just a gradual process.

            Wha?

            I'll grant that curb weight is broadly comparable, but range?

            https://www.motor1.com/reviews/378302/bmw-3-series-tesla-model-3-comparison/

            These two cars weigh roughly the same (1.6 tonnes) and are roughly comparable in terms of size, price, market demographics, etc.

            But the BMW is carrying approx. 45kg of fuel and gets roughly 370 miles to a tank, while the Model 3 is carrying approx. 480kg of batteries and gets roughly 250 miles per charge.

            So that's about ten times the "fuel" weight, for two-thirds of the range; you'd need roughly 15 times the fuel weight to get the same range [*].

            I'm not sure I'd count 240kg - or about 15% of the car's weight - as a "modestly more weight"[*] ;)

            Cars are in something of a sweet spot where the trade offs between range, weight and recharge times are generally "good enough" for non-commercial use. But those trade offs don't really scale down (e.g. motorbikes) or up (HGVs) unless you're willing to make significant concessions.

            OTOH, as you said, battery life is improving, though at current trends, it's going to be a couple of decades before the power density is really comparable.

            And it'll be interesting to see how well Tesla's Semi does. At a glance, it looks feasible on paper for these to displace diesel HGVs (13 hours driving a day = approx. 600 miles per day, so you'd need two charging stops a day), but managing the logistics for charging could be a challenge...

            [*] Plus all the extra weight from uprating brakes etc to handle the extra weight. And from scaling up the car's frame to accommodate the extra batteries without sacrificing carrying capacity, etc. And the extra weight from the batteries you'd then have to add to deal with the extra weight. And so on...

            [*] And with the high end diesel engine in the 330d, you'd get around 600 miles to the tank. Good luck cramming an extra 600kg of batteries into the boot of the Tesla ;)

            1. rcxb Silver badge

              Re: Reserve power?

              So that's about ten times the "fuel" weight, for two-thirds of the range; you'd need roughly 15 times the fuel weight to get the same range [*].

              "Fuel weight" is another ridiculous, unfair measurement. That fuel needs an engine, transmission, fuel tanks, pumps, hoses, firewall, radiator, fans, and more supporting equipment. An electric motor is a featherweight in comparison. That's why curb weight is a vastly better number to go by.

              1. gizmo17

                Re: Reserve power?

                "ridiculous and unfair" seems a bit strong to me, but it's certainly incomplete. Then again, so is curb weight, but in a different way.

                [VW = vehicle weight, FW = fuel weight, CW = curb weight]

                VW + FW = CW

                range_ice = k_ice * FW_ice

                range_ev = k_ev * FW_ev

                What happened with Tesla was, roughly, that k_ev reached a point where range_ev comes close to range_ice at nearly the same CW, because, as you point out, VW_ice is quite a bit less than VW_ev, even though FW_ev is much greater. But it's also undeniable that at present, k_ev < k_ice. So for a small increase in FW_ice, you can get very high ranges, it's just that there's not much demand for it since refueling is fast and easy and no one really wants to drive for 10 hours straight anyway.

                It will be very interesting to see if k_ev is high enough for big trucks now; I suspect it's very close. For planes, I think we have a ways to go.

              2. juice Silver badge

                Re: Reserve power?

                > That's why curb weight is a vastly better number to go by.

                Oh noes. If only I'd taken curb weight into account when comparing these two cars. Oh, wait, I did.

                | These two cars weigh roughly the same (1.6 tonnes) and are roughly comparable in terms of size, price, market demographics, etc.

                Still, I can make things a bit clearer...

                Tesla 3 (Standard): weight 1610kg. Range: 258 miles

                BWM 330i (Petrol): weight 1405kg. Range: 430 miles

                BMW 330d (Diesel): weight 1515kg. Range: 593 miles

                The Telsa 3 is 13% heavier than the petrol car, and has just 60% of the range. It would need to weigh at least 320kg more to match the petrol car's range.

                Then there's the diesel. The Tesla is just 6% heavier, but sadly has just 43% of the range. It would need to weigh at least 650kg more to match the diesel car's range.

                Fundamentally, eCar ranges are in no way comparable to ICE engine ranges. At the current rate of battery technology development (~6% extra capacity per year), it's going to take about a decade for them to be on even terms with petrol engines, and another 4-5 years past there to match diesel.

                To be fair, eCars have a lot of other advantages. But range very much is not one of them.

                1. TrumpSlurp the Troll Silver badge
                  Paris Hilton

                  Re: Reserve power?

                  Comparing eCar range is obviously very interesting but is it strictly comparable with keeping a plane in the air?

                  I assume the range calculations should be for accelerating up to cruising speed then just cruising, which is more or less motorway miles. I think.

                  They stopped using this figure because it didn't reflect real life driving and now calculate fuel consumption and range based on mixed driving patterns.

                  It may be that the comparisons are the same, or it could be that the urban part of the test favours the eCar and the range difference may be larger.

                  Oh, and don't mention VW!

                  1. juice Silver badge

                    Re: Reserve power?

                    > Comparing eCar range is obviously very interesting but is it strictly comparable with keeping a plane in the air?

                    This thread is probably at the point where it should be buried with at least some shreds of it's dignity left ;)

                    But this is a fair point, and the answer is: I don't know :)

                    These days, car manufacturers give three figures for MPG - city, highway and combined. They're still generally on the "optimistic" side; I usually guesstimate real-world MPG to be about 10% below the official figures.

                    Though speed and driving style come into it, too. I had a tyre explode a while ago, and had to gingerly drive back home from Birmingham on the spare (spacesaver) tyre at 50mph. Average MPG for the journey was about 70mpg, rather than the ~50mpg I get when I stick the cruise control on and sit at the speed limit.

                    Back to planes, and their energy usage probably reflects "motorway" MPG the closest. After all, planes would tend to fall from the sky if they encountered a traffic light and had to stop ;)

                    OTOH, there's three stages to any journey. There's getting into motion, keeping in motion and stopping the motion. And for a plane, getting into motion and stopping both require significantly more energy than for a car, since it has to both get up to speed and altitude. Then too, I'm guessing a plane will have to throw away more energy than a car when "stopping", since it still has to actively fight against gravity until it's landed.

                    So, yeah. Personally, I'd be inclined to compare airplane journeys to motorway driving; an initial rampup of speed, followed by long periods of cruising, then a short rampdown.

          3. Alan Brown Silver badge

            Re: Reserve power?

            "Lithium-Air batteries have a theoretical specific power of 11.4 kW/kg, compared to the theoretical maximum of 11.99 kWh/kg for Jet A-1, so very close."

            They have a slight problem in the _rate_ that they can deliver that energy though.

        3. John Brown (no body) Silver badge

          Re: Reserve power?

          Oh, and Register? "...marking a small but significant step on the route to all-electric airliners." Yeah, right.

          Would you not consider the Wright Flyer to be a "small but significant step" on the route to the first airliners? It took some significant steps in ICE design and efficiency as well as advances in materials to get the power to weight ratio to a level where powered heavier than air flight was possible.

        4. Alan Brown Silver badge

          Re: Reserve power?

          "Wasn't there some scam recently where somebody tried selling some ignorant managers that a diesel electric airliner was possible?"

          *Ahem*

          It's _possible_ that a single *core* could directly drive an attached fan and an electrically coupled one (although it might make more sense to just use a generator and drive 2 electric fans, or find a way of mechanically linking the second fan)

          This has been advanced as a way of trying to avoid the never-ending growth of fans on wings, but I suspect it's chasing the wrong rainbow

      2. Jellied Eel Silver badge

        Re: Reserve power?

        I assume they will have to take that into account, are they that slow that they wouldn't make another airport within 5 minutes for an emergency landing?

        Not necessarily a problem. Plane could have EVL (Emergency Vertical Landing) capability with the addition of parachutes that can already be fitted to some light aircraft.

        But I guess if this is intended as a training aircraft, instructors could plan flights so they have emergency landing fields pre-planned.

      3. Captain Scarlet Silver badge
        Paris Hilton

        Re: Reserve power?

        Ok from the downvotes I suppose they are that slow (I don't know how to fly a plane and probably because North Weald Airfield near me is very near Standsted and London City Airport that I think other airfields are all near airports), I'll use the Paris icon next time

    3. Steve K Silver badge

      Re: Reserve power?

      It can only fly for 50 minutes before the plug comes out of the wall......

    4. Len Silver badge
      Devil

      Re: Reserve power?

      I think Loganair could see these get used for at least 40 roundtrips before they need to be recharched.

  6. Greg Dolph

    I have a PPL and the whole part about waiting for the oil temperature to climb is overstated. By the time you do your after starting checks, taxi, do your power checks and wait for traffic it's almost always nice and warm. Only in the dead of winter is there a need to wait, and that's usually pretty minimal, just a couple of extra minutes.

    50 minutes of flight time is *extremely* limited, where I fly it takes 15 minutes to get to the training area each way, leaving 20 minutes of battery, I'd want at least 10 minutes reserve, so that leaves 10 minutes of training time, which isn't even worth it. I wouldn't even be able to leave the circuit in this! I'm sure they'll improve this but at the moment it's hard to see any takers.

    1. Cynic_999 Silver badge

      Many (not all) training flights are booked as 1 hour slots - of which at least 10 minutes will be taken up by taxying and at the hold. So 50 minutes airborne is not ridiculously short - assuming that that includes a reasonable reserve so that the pilot can actually fly for 50 minutes rather than having to subtract a safety margin.

      However if the aircraft is out of action for an hour after every flight to recharge, a flight school will need to have twice as many aircraft. Unless it can be fitted with a quick-change battery arrangement so that one set of batteries can be charging on the ground while the other set is flying.

      1. Anonymous Coward
        Anonymous Coward

        As usual all we get are the 'I need to fly xxx mins and therefore this will never work' view of the world.

        1. Presumably an electric plane uses negligible power while stationary waiting for traffic etc.

        2. It doesn't need warm ups, mag checks etc.

        3. Just because a 'standard' PPL lesson is 60 minutes doesn't mean it has to be 60 minutes long (I soloed a glider with the ATC and not one of my pre-solo training flights was longer than 5 minutes) -.

        4. A canny operator would probably have 1 electric Pipistrelle and 2 piston engined variants. Use the electric version for all the circuit work, use the piston engined version for upper air work and navigation.

        5. This is how we make progress children - we try new things - we push boundaries. We don't sit on the shore muttering 'it will never float'.

  7. Pen-y-gors Silver badge

    Charge time

    Shouldn't be a problem if the airfield can cough up for a suitable charger. 43kW turbo-chargers will give you 25kWh in 40 mins.

    I'm not sure that this is the future though. It's a 2-seater. Tripling the battery size to get a better range would add 300kg to the load, so it probably couldn't take off - even without a crew!

    Until someone can get batteries at 1/4 of the present weight or less, this technology ain't going to be driving airliners.

    1. JDPower

      Re: Charge time

      It DEFINITELY wouldn't take off without a crew.

    2. Anonymous Coward
      Anonymous Coward

      Re: Charge time

      Oh wow - who knew? battery technology matters. Well we are doomed then - because we all know batteries are made of lead and lead is really heavy - plus acid...acid is corrosive. Better no even think of trying it.

      1. John Brown (no body) Silver badge

        Re: Charge time

        "because we all know batteries are made of lead and lead is really heavy"

        Mythbusters made a lead balloon fly. Maybe the future is electric dirigibles with paint-on solar cells across the entire upper skin?

  8. juice Silver badge

    Here we go again...

    > Conspicuously absent from the publicity material is mention of the charging time for the Velis Electro

    At 25kw, the plane's battery has roughly quarter the capacity of the battery from a Tesla Model S.

    Charge times for those range from 1 to 10 hours.

    https://www.energysage.com/electric-vehicles/charging-your-ev/charging-a-tesla/

    So in theory, you could be back up in the air in 15 minutes /if/ you can hook it into a Tesla supercharger or equivalent thereof.

    Which is good, because with a 50-minute charge, you've presumably only actually get around 20 minutes of actual flight before you have to drop back down to earth again...

    Snarking aside, it does feel like it's maybe a bit early to be pushing something like this out. I appreciate there's some advantage to being an early mover, but it's still taking me back to the days of 16mb MP3 players which used battery-backed RAM to store their music ;)

    1. Cynic_999 Silver badge

      Re: Here we go again...

      Provided you can supply enough current to meet the maximum charge rate of the battery, charge time has *nothing* to do with battery capacity. If it did, then using your Tesla example, you should be able to charge your phone in a few seconds! Or you could halve the charge time by using two 12.5kW batteries that you charge at the same time instead of using one 25kW battery!

      In fact minimum charge time is pretty much the same for any particular battery technology regardless of the battery capacity.

      1. Yet Another Anonymous coward Silver badge

        Re: Here we go again...

        But charging rate does depend on battery configuration, cooling etc.

        My car can supercharge quickly because it has an active liquid cooling system for the battery - I suspect the plane doesn't.

        1. IGotOut Silver badge

          Re: Here we go again...

          I guess you missed the paragraph

          "The revolutionary powertrain is entirely liquid-cooled, including the batteries, and demonstrated the ability to withstand faults, battery thermal runaway events, and crash loads as part of the certification process,"

          1. 2+2=5 Silver badge
            Joke

            Re: Here we go again...

            So a stated benefit is not having to wait for the oil to heat up, instead you will have to wait for the battery to cool down from the rapid charge.

        2. Anonymous Coward
          Anonymous Coward

          Re: Here we go again...

          As this aircraft would almost certainly be used for local flights from it's home base - you could quite feasibly add a stonking great ground based cooling system that you connect up while you are charging - but leave behind when flying.

      2. juice Silver badge

        Re: Here we go again...

        > In fact minimum charge time is pretty much the same for any particular battery technology regardless of the battery capacity.

        Woah there, Nellie. I was scribbling on the back of a beer mat, not building a charger network ;)

        I'm well aware that there's two stages to charging:

        1) A "fast" stage, where you pump electrons in as fast as you can, which gets you up to about 60% of capacity

        2) A "rampdown" stage, where you keep reducing the amperage as you get closer to a 100% charge.

        The key point is that while the time needed for 1) can theoretically be reduced to zero, you're still stuck with 2)

        And there's lots of clever people doing their best to work out how to improve both stages, through things like hardware improvements, better monitoring software, active cooling systems, accepting trade-offs on longevity, etc.

        Then too, some companies are claiming to have mobile phone chargers which can deliver a full charge in around 30 minutes - or even 13!

        https://www.theverge.com/2019/6/20/18692589/vivo-super-flashcharge-120w-fast-charging-time

        Personally, I think I'd stand well back and keep a (powder) fire extinguisher handy...

    2. John Brown (no body) Silver badge

      Re: Here we go again...

      "Snarking aside, it does feel like it's maybe a bit early to be pushing something like this out."

      It reminds me of the Bob Newhart sketch re. the Wright Brothers

  9. Holtsmark

    "The EU Aviation Safety Agency (EASA) has certified its first all-electric aeroplane for routine use"

    Hmmm..

    what comes first, 2006 or 2020?

    https://www.easa.europa.eu/sites/default/files/dfu/EASA-TCDS%20A%20092%20E1%20Antares%20issue%202.pdf

    Off course, one is an aircraft built around and optimized for electric flight, the other is a conventional looking aircraft with an electric propulsion option.

  10. anthonyhegedus Silver badge

    I'm not convinced, but it's a start. However, physics does limit it somewhat. What about a 'hybrid' - where a fuel-efficient engine can charge the batteries, but it would make for quieter take-offs? Short flights could be entirely battery-powered and charging could take place using greener energy at the airfield.

    1. Cynic_999 Silver badge

      Hybrid arragement

      Aircraft engines need to be big enough to supply the maximum power demand - which is only needed during takeoff and initial climb. For the majority of any flight, the engine is producing significantly less than its maximum power.

      So - you could fit a smaller petrol engine but have batteries supplying the extra power needed for takeoff and climb. As soon as the aircraft levels out in the cruise, the petrol engine can supply all the power the aircraft needs plus a bit extra to charge the batteries so they are ready for the next takeoff.

      Such a hybrid power chain adds weight - whether that will be more or less than the weight saved by the smaller engine is a matter for the design engineers to calculate.

      A hybrid arragement would also add to safety by giving an alternate power source in the event of an engine failure that would improve the chance of making it to a suitable place to land.

      1. IGotOut Silver badge

        Re: Hybrid arragement

        Rather than the regular car hybrid model, you go the generator hybrid model.

        Smaller engine running at constant revs is far more practical than a bigger engine reving all over the pace.

        Add to that engines are getting lighter and stronger. We are working with a hypercar maker whose new engine block you can easily lift with one hand, yet revs to up to 10,000 rpm.

        1. jake Silver badge

          Re: Hybrid arragement

          "new engine block you can easily lift with one hand, yet revs to up to 10,000 rpm."

          I had that in a race-prepped Mazda RX3 back in 1977. Was a 12A with what we would probably call a mild street-port today ... More modern, and more HP and torque, my little brother has a Honda Civic with a K-series that is built to do that. He keeps it rev-limited to about 8,000RPM for longevity, but has been known to turn it up at the track.

        2. Anonymous Coward
          Anonymous Coward

          Re: Hybrid arragement

          whose new engine block you can easily lift with one hand, yet revs to up to 10,000 rpm.

          I had an engne like that. It had a Glo-Plug for ignition as well.

          Power output wasn't great, though...

        3. Anonymous Coward
          Anonymous Coward

          Re: 10,000 rpm

          Is it a 2T to only rev so slowly? ;-)

          Anyway, drag is proportional to the squared velocity of the piston, which is why 2T rock! Quite literally, more bang per buck

      2. John Sturdy
        Boffin

        Another kind of hybrid

        Since the maximum power is needed at the start, another way to conserve the aircraft's on-board energy stores is to use a launch catapult, as done on aircraft carriers. It would still make sense for it to be able to take off without that, but it could help when it is available. Or maybe a static winch to help with the launch and the first part of the initial climb, as for gliders?

        1. John Brown (no body) Silver badge

          Re: Another kind of hybrid

          "Or maybe a static winch to help with the launch and the first part of the initial climb, as for gliders?"

          Do you think that might be scaleable for wide body long haul flights in the future? Maybe the future is all electric short haul and the long haul stuff will be done by SpaceX BFRs? (kidding here, maybe, sort of)

      3. John Brown (no body) Silver badge

        Re: Hybrid arragement

        "So - you could fit a smaller petrol engine but have batteries supplying the extra power needed for takeoff and climb. As soon as the aircraft levels out in the cruise, the petrol engine can supply all the power the aircraft needs plus a bit extra to charge the batteries so they are ready for the next takeoff."

        That sounds overly complex. I thought a "traditional" hybrid" engine was electric motors powered by a generator/batteries.

  11. Anonymous Coward
    Anonymous Coward

    "one hopes a potential crash involving one won't pose problems similar to those faced by firefighters tackling Tesla crashes."

    Or problems similar to firefighters tackling conventional aircraft crashes...

    1. Anonymous Coward
      Anonymous Coward

      When a crashed conventionally fueled vehicle fire is doused, it stays doused. If you can manage to get an electrical cell fire doused (which is surprisingly difficult), there's a greater than even chance of it spontaneously and unpredictably recombusting several days later.

    2. werdsmith Silver badge

      Or maybe like the Yuasa battery packs on early Boeing 787s that caught fire even without crashing.

  12. J4

    The silence of the lands

    Electric trainers will be an absolute boon for flight schools anywhere near a built up area. They are under continuous pressure from local residents about noise, and the worst noise generators are the mid stage trainees in circuits going round and round at 700ft practicing landings. 50 minute endurance is absolutely fine for that purpose, and the piston aircraft can be used for the training exercises at altitude.

    1. whitepines Silver badge

      Re: The silence of the lands

      I keep hearing noise being cited as an advantage, but honestly on your average GA light aircraft how much of that noise is from the prop vs. the engine? Especially with students that think they're flying a rocket not a plane and take off at an accordingly steep angle with prop pitch at full coarse?

      1. Holtsmark

        Re: The silence of the lands

        Half of the noise of a conventional GE aircraft can easily come from the prop.

        In order to make an electric plane silent, you need to install a prop with a sufficiently low disk loading. This may require moving toe prop away from the nose.

        1. not.known@this.address Silver badge
          Coat

          Re: The silence of the lands

          <quote>

          In order to make an electric plane silent, you need to install a prop with a sufficiently low disk loading. This may require moving the prop away from the nose.

          <end_quote>

          Edgley Optica for the win! Has the added advantages it already looks like it's from a science fiction film (!!) and its BRITISH!

          (cough *Slipstream* cough)

      2. Anonymous Coward
        Anonymous Coward

        Re: The silence of the lands

        Rich students. Not many ab-initio pilots fly in aircraft with variable pitch props.

        1. Cynic_999 Silver badge

          Re: The silence of the lands

          Very true - and even rich students will almost all start training in a basic aircraft and then do a type conversion to a more complex aircraft only after gaining a PPL. For the same reason that people usually learn to drive in a car rather than an articulated lorry.

      3. Cynic_999 Silver badge

        Re: The silence of the lands

        Ummm -

        1) The vast majority of GA training flights are in an aircraft with a fixed pitch propellor

        2) In VP aircraft attempting to take-off in full coarse pitch would be a huge mistake and probably culminate in a failed take off or accident. So is a very, very rare occurance.

        2) Take-off and initial climb in small training aircraft aircraft will *always* be done at full power.

        3) The angle of climb will not affect the amount of noise - and in any case will be at the recommended speed (and climb angle) for the aircraft configuration. Attempting to climb-out much steeper than that will lead to a stall and probably a fatal crash - though a steeper climb angle can be deliberately achieved by the use of a different flap setting and climb speed, which is practised in the PPL syllabus as a "short-field takeoff"

        1. ICL1900-G3

          Re: The silence of the lands

          I suspect the OP knew a little, but not much, about flying.

          1. whitepines Silver badge

            Re: The silence of the lands

            I suspect the OP knew a little, but not much, about flying.

            Guilty as charged. I'm still learning and as you can tell I have a ways to go.

            That said, I have noticed the absolute noisiest takeoffs in prop-driven aircraft being at the steepest climb angles for a while now (I live near a GA airport). Those doesn't really sound like classic engine exhaust noise either, more of a sharp noise I'd associate with the propeller, and as the aircraft passes that noise diminishes sharply and you hear the engine itself more clearly (and a lot quieter).

            In VP aircraft attempting to take-off in full coarse pitch would be a huge mistake and probably culminate in a failed take off or accident. So is a very, very rare occurance.

            Interesting. From a physics perspective why is this the case? Not doubting what you are saying in any way, but it seems counter-intuitive from the standpoint of taking off at maximum possible power output.

      4. werdsmith Silver badge

        Re: The silence of the lands

        Light aircraft engines on the old Cessa/Piper fleet are generally quite noisy, the exhaust manifold exits to a short pipe just below the engine cowling and the weight of a decent sincerer was never thought to be a requirement.

      5. John Brown (no body) Silver badge

        Re: The silence of the lands

        "I keep hearing noise being cited as an advantage,"

        I wonder just how much actual noise an electric motor powerful enough for a take off there will actually be? And will the complainers thinks it's louder because it's a different noise, high pitched whine rather than than the deep bass thrum of an ICE engine they are "used" to?

    2. springsmarty

      Re: The silence of the lands

      This is a classic disruptive technology per the book Innovator’s Dilemma. One application of a new technology is identified, in this case probably to reduce noise where noise is a pressing concern. The old guard immediately notes that the technology will not work in all use cases, so it is therefore pointless. Meanwhile, the technology continues to mature and find new uses until the old technology eventually becomes obsolete. I don’t know if electric aircraft will eventually take over the world, but I was equally skeptical of electric cars initially, yet now I drive one.

      So many technologies went through a similar path. Just in the past 10 years we saw SSDs emerge in niche areas, while the old guard proclaimed loudly that the tech could not replace disk drives: too expensive, too unreliable, not dense enough. Yet here we are now, with SSDs displacing spindles for all but a few storage edge cases.

  13. David Pearce

    Twin engines?

    If battery capacity ever gets useful, the light weight, small size and low maintenance of the electric motor compared with a 6L Lycoming makes twin engines far more practical. Smaller props would then solve the biggest problem of a Cessna 172, you cannot see ahead, especially when climbing

  14. ratfox Silver badge

    It's good that this is becoming possible, but what I'm wondering is if it will open new possibilities. Electric engines are more versatile than gas ones; for instance it's not a problem at all to cut the engine and restart it later. Could this enable hybrid plane-gliders that would glide as much as possible, and only restart the engine when needed?

    One thing that has struck me is how remote-controlled drones are almost always quadcopters, instead of looking like regular helicopters. If you take away some constraints, suddenly you have a lot more possibilities and you find different solutions. I hope that electric planes could bring some fresh designs.

    1. David Pearce

      Good point about the quadcopters. This is done to avoid the complex and fragile universal joint, that makes real helicopters so expensive to maintain and has killed so many pilots. The accident rate of helicopters compared with small fixed wing aircraft is about ten times worse

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