EU aviation wonks give all-electric training aeroplane the green light – but noob pilots only have 50 mins before they have to land it
- Reference: 1591881309
- News link: https://www.theregister.co.uk/2020/06/11/easa_certifies_pipistrel_electric_aeroplane/
- Source link:
"This is an exciting breakthrough," said EASA executive director Patrick Ky in a canned statement as he boasted about the Pipistrel Velis Electro gaining its type approval from his agency.
A two-seater "intended primarily for pilot training," the Velis Electro is a development of Pipistrel's existing (and unfortunately named) Virus aeroplane, which features a piston engine instead of an electric motor.
Over three years the Slovenian airframer tested both the aeroplane itself and its novel electric motor and battery arrangement. In cockpit terms the instruments and controls provided to the pilot closely resemble those of conventional aeroplanes.
[1]
Click to enlarge
Ivo Boscarol, founder and CEO of Pipistrel Aircraft, gushed: "The type certification of the Pipistrel Velis Electro is the first step towards the commercial use of electric aircraft, which is needed to make emission-free aviation feasible. It is considerably quieter than other aeroplanes and produces no combustion gases at all."
Thirty aircraft have so far been pre-ordered.
One potential problem with the Velis Electro is its short [2]endurance of 50 minutes from a [3]designed battery capacity of 24.8kWh; this compares unfavourably with aged (in some cases 40-year-old) Pipers and Cessnas which currently dominate the basic flying training sector, whose endurance is measured in hours.
"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," said Pipstrel in a statement.
Its point about crash loads is significant. Perhaps the closest comparator to the Velis Electro is Tesla's Model S, which has suffered a number of [4]concerning battery fires over the years. With the Velis Electro having passed newly devised certification tests for its electrical supply, one hopes a potential crash involving one won't pose problems similar to those faced by firefighters tackling Tesla crashes.
FYI... Europe has OK'd electric gliders for a while, for example [5]this one .
On the flip side, the electric motor doesn't need warming up like a piston engine, increasing the amount of time the Velis Electro can be used for actual flying instead of sitting on the ground waiting for the oil temperature needle to inch its way into the green sector.
Conspicuously absent from the publicity material is mention of the charging time for the Velis Electro, although there is quite a bit of detail about the battery and cooling arrangement on the company website. One battery pack is mounted between the motor and the instrument panel with the other being behind the pilots' seats.
If one pack malfunctions, it drops out of the motor circuit; either can keep the aircraft airborne on its own, with Pipistrel stating that climbing to higher altitudes is still possible in the event of one pack failing.
Flight testing and the certification itself was carried out by French and Swiss aviation authorities who signed it off to EASA standards. The liquid-cooled battery and 76hp motor arrangement from the Velis Electro is said to be available to other manufacturers as a drop-in unit, having been separately certified from the airframe in May.
Meanwhile, in the UK, an [6]all-electric airliner engine's planned test regime was cancelled earlier this year. ®
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[1] https://regmedia.co.uk/2020/06/11/pipstrel_velis_electro_cockpit_2.jpg
[2] https://www.pipistrel-aircraft.com/aircraft/electric-flight/velis-electro-easa-tc/#tab-id-2
[3] https://www.pipistrel-aircraft.com/aircraft/electric-flight/velis-electro-easa-tc/#tab-id-1
[4] https://www.theregister.com/2016/09/07/tesla_model_s_crash_electrical_hazard_fire_brigade_netherlands/
[5] https://www.schempp-hirth.com/en/individual/engine-options/fes-front-electric-sustainer
[6] https://www.theregister.com/2020/04/27/airbus_rolls_hybrid_plane_grounded/
[7] https://go.theregister.com/tl/1956/-8478/why-container-security-matters-to-your-business?td=wptl1956
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.
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.
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...
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.
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.
Re: Boost from Solar?
Nah, with all that wind whistling by they should fit wind turbines
Does it have regenerative braking?
Does it have regenerative braking?
(twice, for redundancy)
Re: Does it have regenerative braking?
There is an optional wind turbine to charge the battery
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).
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
Re: Reserve power?
Can of Redbull?
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?
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.
Re: Reserve power?
It can only fly for 50 minutes before the plug comes out of the wall......
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.
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.
Re: Charge time
It DEFINITELY wouldn't take off without a crew.
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 ;)
"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.
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.
"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...
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.