Stefan Drury’s YouTube video about the Pipistrel Alpha Electro is a great way to spend 9:27 of your precious time.
The video is beautifully shot and marvellously edited. This isn’t Stefan’s first video. That is obvious.
But two simple sequences in the video jump out at me.
The first takes place in the intro and is then repeated, with necessary details, at the one-minute mark.
One moment, the motor is not running. In the next moment, it is.
That is terribly exciting to me.
A few summers ago I flew from Denver to Oshkosh for AirVenture with a couple of friends in their Cirrus SR-22T. We planned for, but failed to execute, a quickturn in Iowa.
We just couldn’t get that wonderfully thirsty – and still hot – engine started. Thus, our quickturn became a slowturn.
I also recall performing the hot engine start dance – twice – in our Beech Baron each time we stopped for fuel.
I’ve long been frustrated at the difficulties of starting an aircraft engine. Especially compared to the ease-of-use of automobile engines.
The other interesting point in the video is when the discussion turns to flying time versus charging time.
“Generally speaking, for about an hour of flying it’s about an hour ten to hour fifteen minutes of charging,” says Barrie Rogers from Eyre to There Aviation.
Fly for an hour. Charge for an hour plus a little.
While that performance would make a cross-country flight an exercise in patience, that isn’t what the Alpha Electro is for.
Each time I’ve written about electric-powered aircraft I’m told, repeatedly, that avgas has a higher energy density compared to batteries for a given weight, among other challenges.
I’m certain those who tell me that are correct.
But the Alpha Electro is a trainer, with lots of one-hour flights in its future. These flights aren’t speculative or some day dreams. They are happening today.
I imagine battery engineers are working on ways to increase the amount of charge a battery can hold for a given battery and increasing the speed to re-charge.
In avgas burning aircraft, the analog is installing larger fuel tanks and using a larger diameter fuel hose.
I have no idea when, or even if, battery technology will make a significant leap forward. But I bet Ford, with its newly announced 2022 F-150 Lightning, not to mention Tesla, GM, and every other automaker and computer manufacturer all have their sights and budgets aimed at improving battery tech across the board.
A recent story in Forbes reports as much regarding development of aluminum-ion batteries.
Whether a student flies an hour-long lesson in the Alpha Electro or a Cessna 152 matters not. The time and training will be the same.
The difference, in this case, is on the ground.
A Cessna 152 can be re-fueled more quickly than the Alpha Electro can be re-charged. How much quicker? If your flight school is finely tuned like a Formula 1 pit crew, there is no competition. But most flight schools don’t quite meet the F1 standard.
A flight school with fuel trucks increases the efficiency of prepping the airplane for the next lesson. While the student and instructor secure the airplane, the fuel truck can roll up to top the tanks. But if the student has to taxi to a fuel pump, pump the gas, then re-start and move to secure the aircraft, the difference starts to narrow.
To me, this is akin to the high-wing or low-wing argument. Some pilots prefer to sit atop the wing, others prefer to hang below. Neither is right. It is a matter of preference.
I haven’t had the pleasure of flying in Pipistrel’s cute little trainer. I look forward to changing that at some point in the future.
Very nice article, we hope to develop it to a lever of long distance flight.
I will be happy to hear more and to promote it in Israel and the mideleast.
Yoram Sadan
Why do I not read about the “interchangeable battery option with these aircraft. There could always be a battery on the charger; land and remove the one in plane and exchange with one on charger. Easy access, secure positioning and plug design are easily engineered option.
This 480 volt ,300 pound battery is not as easy as changing a 12 volt, 24 pound battery.! [ based on the Tesla 100 kWhr battery weighs 1,375 lb ]
It will take a forklift and some serious engineering to design the disconnects, since this battery is capable of over 100 amps !
It seems to me that the 1.2-1.5 hours to recharge is a safer option.
Cross country flight needs 250 nm plus reserves for a commercial. Flight schools won’t a fleet that has only 4 hours a day in 1 hour blocks.
FAR 61 & 141 will need major revision.
Or nuclear power like a satellite.
Every article speaking to battery power, brings out all the naysayers and experts who feel the need to restate the obvious. Your article made it clear that yes, this particular aircraft is certainly viable as a flight trainer. There are certainly other scenarios for refueling, including simply designing the battery bay to allow for quick change to freshly charged batteries. There are self launching sail planes that use this system already. If your article was intended to show the very real use of electric powered flight in a training situation, you absolutely did that.
I’ve worked in Signal Engineering for 42 years. LA batteries can short out, super heat and explode. I’ve seen this happen at least 10 times. I’m not a fan of using batteries in an airplane as they should be changed at least every couple of years. Safety first!
Gasoline has certainly had its fair share of inflight fires, not to mention fires upon landing or crashing. So I guess I am confused as to why one is “safe” (gasoline), and one is not (batteries)?
My 172 has 6hrs endurance. Therefore at least 4, 1hr sessions before refueling !
The technology this type for aircraft is not here yet. FAA will require extensive testing and certification and it is a long way off.
If anyone believes an all electric power airliner is doable is smoking something!
I don’t believe I wrote anything about an “all electric power airliner”.
There were a lot of comments on another story in this…It’s an expensive toy !
It may be useful in EU with all their repressive regs. and fees.
There is no ‘magic’ battery on the horizon….al- carbon , or others.
Sorry, avgas will be king for decades.
On e these move away from Lithium Ion and start using LiFePO4 batteries then they will be worth the money. No explosion hazards, 10 year battery life, lighter weight, and higher density. I’m actually shocked they even used LI.
Ben, I’m so happy to see you guys write about electric aviation, something I have been involved with for the past 15 years.
Thank you, Nicolas
What a great concept, no doubt it will be successful.
Realistically these things are just prototypes at best. When solid state batteries finally get here and have far less weight and greater range then something real could happen. These new batteries are also going to possibly be based on salt which will alleviate the rare Earth materials problems associated with Lithium.