Electric regional air mobility will disrupt aviation from below, Michael Barnard argues:
Jet engines especially became more and more efficient. At least, as long as they were flying at 38,000 feet at optimal cruising speed. Modern large diameter jet engines are miracles of engineering, turning a full 50% of their fuel’s energy into forward motion under those conditions. However, when taxiing or waiting on a runway or even taking off, it’s like pouring kerosene onto the tarmac. The economics of the engines favor longer flights.
In the USA, where so many smaller aircraft were manufactured, there was another duck through the windshield, product liability. The legal environment of the era allowed virtually unlimited liability for airframes even decades after manufacturing. Insurance costs sky rocketed, many small aircraft manufacturers went out of business and larger firms stopped making smaller aircraft.
This was recognized and Congress passed the 1994 General Aviation Rehabilitation Act or GARA, which limited airframe liability to 18 years. With GARA, smaller aircraft started being produced again, albeit in smaller numbers.
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The combination meant that although there are over 5,000 airports in the United States and thousands more in Europe, under 1% of them service over 70% of passengers. Once a business model is baked in, it takes something disruptive to transform it.
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But why are electric airplanes cheaper to fly? For the same reason that electric cars are cheaper to drive. Electric drive trains are vastly more efficient than ones that burn fuel. While the 50% efficiency of modern jet engines is amazing and modern gas turbine aviation engines see that efficiency at optimal speeds, battery electric aviation drive trains are 95% efficient. Further, they are 95% efficient or more when rolling around on runways or sitting still. Pre-flight checks with battery electric aircraft don’t need to keep the propellor turning, something that is causing confusion on small airfields the first few times electric aircraft fly there.
And the simplicity of battery electric drive trains reduces maintenance costs as well. Instead of fuel tanks, fuel pumps, fuel lines, complex engines, exhausts, radiators and lubrication systems with many, many moving parts, electrons flow along wires from a battery to an electric motor that turns the propellors, with a single moving part in the motor. This significantly reduces the duration of all maintenance and inspection activities, allowing the plane to fly more hours with less human intervention.
And simple, battery electric, fixed wing aircraft will be cheaper to certify in the future. At present they are novel, but civil aircraft certification is an n times n safety cross check, with every combination of conditions having to be validated in manufacturing and flight tests before NASA or EASA will allow passengers to be carried. With electric aircraft, there are a lot fewer n times n combinations because there are so many fewer moving parts and sub-systems.
This doesn’t apply to the urban air mobility Jetson dreams of electric vertical take off and landing aircraft by the way. They are complex, have multiple novelties and many more failure conditions, so certification is likely to be US$1.5 billion per machine, money that companies like Archer and Joby don’t have and realistic assessments of their business cases don’t support. More on that in a future article.
Battery energy density is not as significant a constraint as many have been assuming. Yes, batteries carrying the same energy as aviation fuels are much heavier than the fuels, but the efficiency cuts into that. With current energy density and smaller aircraft, ranges of over 200 miles are easily achievable. With CATL’s new condensed matter batteries, shipping this year, double that range with the same weight is viable.
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Automating aircraft flight is actually easier than automating driving to work. Airport aprons and runways are carefully controlled environments with many fewer moving vehicles, much lower speeds and no children on tricycles. Once in the air, it’s actually quite hard to hit anything except the ground. There isn’t a lot up there and there’s a lot of room in all directions to go around anything which shares airspace. Autopilots have been able to land and takeoff for a long time and big jets frequently use it, especially in low wind, low visibility circumstances. although there is still plenty of pilot involvement and oversight.
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The lingua franca of air traffic control will change from English to computerese, with humans overseeing the process.
When that occurs, the pilots can leave the cockpits and oversight can be from the ground. This is starting with smaller cargo aircraft flying carefully designed low-risk routes. No school yards will be overflown for years.
“Autopilots have been able to land and takeoff for a long time and big jets frequently use it, especially in low wind, low visibility circumstances…”
Yeah, the low wind part is important. Trying to land a plane in a heavy crosswind is a bitch. That’s a major barrier to getting a pilot license. It was for me, for sure! If crosswind landings get safely automated, it will open flying to a lot more people.
“Urban air mobility” is doomed to fail, and deserves to.
Why won’t the U.N. Green New Dealer freakazoid contingent work to bring personal autogyros to the American mass instead?
Perhaps because the American mass is now deep, deep down into the physiognomical death spiral due to the quote-unquote thought leaders’ own catastrophic quality-control failure and sabotage?
I know how to fix it; I know how to pull back from the brink. Deep down, everyone knows.
“Once in the air, it’s actually quite hard to hit anything except the ground. There isn’t a lot up there”…that’s not true at all in areas around high-traffic airports. And if electric aircraft become as visible as envisaged, there will be a lot *more* up there, and the problem of air traffic control becomes much more difficult.
A commercial plane has to carry freight and passengers at a profit. More freight and passengers mean more revenue. Batteries mean more weight and less revenue. The business model doesn’t work.
An electric battery will have 10 times the volume and 10 times the weight of the fuel it replaces. I find it hard to believe an all electric system can replace a fossil fuel system.
The other point is battery life. EV batteries are warranted for only 100,000 miles or 8 years, after which they must be replaced at costs ranging from $10,000 to $30,000, which means the EV has 0 resale value.
Batteries also lose charge capacity. An EV battery at end of warranty will hold only 70% of its original charge.
Then there is the fire issue. NYC’s fire department recently noted that electric scooter battery fires are now a major safety issue and a major cause of fires in the city, over 100 so far this year. The scooter batteries have to be brought into apartments for recharging, and the fires frequently cause injury and even death.
The safe assumption is that whatever an environmentalist tells you is a lie.
Power beaming stations built along air traffic corridors could help electric aircraft overcome the limitations of battery power.
“But why are electric airplanes cheaper to fly? For the same reason that electric cars are cheaper to drive. Electric drive trains are vastly more efficient than ones that burn fuel. While the 50% efficiency of modern jet engines is amazing and modern gas turbine aviation engines see that efficiency at optimal speeds, battery electric aviation drive trains are 95% efficient. Further, they are 95% efficient or more when rolling around on runways or sitting still.”
Someone mainlined the EV Kool-Aid there.
Peter, re: “Power Beaming Stations.” Brilliant idea. Build giant induction coils in the sky and make planes fly within them. I can’t see any problems with that, can you?
Filling the skies above Washington or Brussels with decently sized remotely controlled aircraft sounds like an excellent idea. To save the environment/planet we should implement this idea post-haste and accept any side effects as the unavoidable consequences of progress.
“Mentour Pilot” youtube channel tried out the Pipistrel Velis Electro at Green Flight Academy in Skellefteå, Sweden. Summary: Good for training flights <1 hour. Very short range, have to stay near the airport. It helps the airport is located near a cheap source of electricity. The electricity cost is negligible (about €1/hour), the bulk of the cost comes from the battery: €22,000 for 500 hours. So running cost is about €45/hour, which is very good.