The Electric Airplane Performance Dip

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I spent a good portion of January conducting interviews and research for a major print piece on electric aircraft to appear in the March issue of Aviation Consumer. My impression is that there's as much going on in this field beneath the surface as there are known projects. Expect to learn more in 2016.

Last year, we reported on the surprise development of Airbus getting into the electric airplane market at the GA level. Such as it's possible to judge the seriousness of such things, Airbus' $55 million project looks as serious as any. It's building a factory in France to produce the E-Fan 2.0—a pure electric trainer—in volume for a rollout next year. It pledges to design and certify the four-place hybrid E-Fan 4.0 for the North American market before 2020. As part of my research, I asked Airbus for some additional detail on these airplanes, but not much is forthcoming just yet.

As to the question why Airbus is doing this, I got this carefully crafted answer via email from Ken McKenzie, Airbus' senior VP for strategy and development: "We believe the larger focus of an innovation project like the E-Fan is not to necessarily make an aircraft that's cheaper to produce, operate and maintain than an aircraft with a combustion engine, but rather, to develop innovative, eco-friendly propulsion and lightweight material solutions, with the goal of bringing them to market quickly as more stringent carbon emissions regulations come into effect."

If there's an oh-I-see moment in this electric airplane business, that's it. Now I already knew this about Airbus' motivation and you probably did, too, but seeing it stated so succinctly is refreshing. In Europe, they've accepted that carbon load regulations are coming and are preparing for it. In the U.S., we haven't quite got past the it's-all-a-hoax stage, jollied along by several current presidential candidates who sense a conspiracy. No surprise then that so much electric aircraft research is coming out of Europe and Asia. Whether you think carbon pollution is a hoax or not is less relevant than the fact that companies are going to start selling electrics.

Question is, will anyone buy? I'm interested in the market uptake of these first-generation electrics for several reasons. One, they're technology demonstrators so we'll get to see how they work juxtaposed against what buyers think they should do. And two, the companies selling them have to build enough airframes to sustain the effort and, as telegraphed by Ken McKenzie's comment above, that doesn't necessarily mean short-term profits. It means building an installed base of sufficient size to learn how electric airplanes fit into the GA ecosystem. Or even if they fit.

Carbon regs will push things along in Europe, but even so, buyers will have to confront what I'll call the performance dip. By that, I mean that an electric airplane—pure electric or hybrid—will be significantly compromised against the equivalent airframe with a conventional gas engine. It won't carry as much payload, it won't go as fast and, in the case of EVs, it won't have nearly the same endurance. At this stage, even the hybrids appear to give up performance. They suffer in payload because they have to haul a couple of hundred pounds of batteries and they suffer in cruise because to make the economics work, they necessarily have a smaller internal combustion engine than that which they may compete against.

As battery energy density improves, so will EV endurance, but it will be a gradual ramp up, not great bounding leaps. As explained in this podcast with battery expert Jeff Chamberlain, lithium ion capacity will inch up at the rate of 7 percent a year for the foreseeable future. The big lightning-in-a-bottle batteries—lithium air and maybe lithium sulfur—may be at least a decade away. So will the performance dip discourage buyers? My guess is it will. But manufacturers of these airplanes will argue that this misses the point and that early-stage electrics are meant to knock down the certification barriers and hunt around for potential market traction. Worth noting is that manufacturers of automotive EVs and hybrids have the same problem. Sales of both of those categories are flat, after several years of robust growth. No one knows if this is a broader trend or a temporary market decline. It began before the current collapse of oil prices. 

Between emerging carbon regulations in Europe, the inevitable early adopters and eco-conscious buyers, EVs and hybrids will find some sales. Moreover, Pat Anderson, an Embry Riddle professor and researcher working on electrics, tells me that young people interested in aviation are eco-centric and will tilt toward green solutions. By the time electrics mature, those kids will be making the buying decisions on replacement airplanes. Frankly, I find that encouraging. We're long past due for thinking in GA not bounded by the established values of people who learned to fly in the last century.

I predict the electric market will develop about like the diesel market did. Initially, diesels were slower and had low TBOs, but that didn't stop the technology from carving out about a 10 percent market share over a decade because some buyers liked the economy and ease of operation. Diesel had only operating costs going for it, not favorable regulations on noise and emissions as electric airplanes will have.

Because Airbus' overarching goal is to lay the initial bricks for commercial electric aircraft, I suspect they'll Dutch the board with a complete system for buyers, from battery support and maintenance to training materials and doctrine tailored to the limitations of EVs. I'll be surprised if they simply roll the airplane out of the factory with a take-it-or-leave-it price. It will take a major push to overcome the considerable disadvantage these electric airplanes will have.

Ultimately, where Airbus is headed is an electric hybrid regional airliner called the E-Thrust project. With a 2050 timeline, that airplane has proposed technology that doesn't even exist commercially yet. The real seismic shift will occur not with battery technology but with integrating electric propulsion with low-drag, efficient airframes that only electric propulsion can make possible. I see this going on experimentally, but real airplanes? It will be a while. You probably read that tech whiz Elon Musk says he's going to launch his own electric airplane project, a supersonic design no less. And just today, we reported that Pipistrel powered up for the first time a powerful hybrid-drive system at its Solvenian factory. 

What will be interesting for the next generation of journalists covering this—won't be me—is whether the performance dip really is a dip, to be recovered and bettered as the technology advances. My guess is that's exactly what will happen because the nature of transportation has always been faster, better and more efficient, even if the iterations along the road sometimes take steps backwards. That's the nature of progress. It's also the nature of progress to not know what's coming or to be wrong in predicting what is. More than once I've heard people in this field say words to the effect that at this point, we don't even know what we don't know.

Research is supposed to unmask those mysteries but inquiry inevitably also leads to blind alleys. At the moment, the future of electric airplanes is too uncertain to say which is which. But those who insist electric airplane will never be a thing are kidding themselves.

Comments (40)

No dip in ambivalence. Electric airplanes will never be in our collective lifetime.

Posted by: Rafael Sierra | February 18, 2016 10:30 PM    Report this comment

Yes, less range, less useful load and going slower all at the same time at who knows how much more cost. Sounds like a winner to me. Tesla can't keep their cars in the show room. When was the last time you saw a Volt pass you by? When was the last time you saw a Volt? And diesel's are just going through the roof.

Posted by: Thomas Cooke | February 19, 2016 5:24 AM    Report this comment

Just when I had resigned myself to installing a diesel in my Corsair, now I have to put an electric motor in my Pitts Spl.

Posted by: Richard Montague | February 19, 2016 7:39 AM    Report this comment

For a well-known aerospace engineer's perspective on the whole climate change business, just Google Burt Rutan's presentation on climate change.

Posted by: James Beaver | February 19, 2016 8:13 AM    Report this comment

For a well-known aerospace engineer's perspective on the climate change business, Google Burt Rutan's presentation on climate change.

Posted by: James Beaver | February 19, 2016 8:15 AM    Report this comment

James Beaver, don't get too enthused over Rutan's conclusions on climate change. Go to the following link and enjoy: Taming.wordpress.com/2012/01/29/some-questions-for-rutan/

Posted by: Rafael Sierra | February 19, 2016 9:14 AM    Report this comment

What's the difference between GA air polution and that caused by motorboats, lawnmowers, and leaf blowers? Every butt-hole and his brother owns a motorboat, a lawnmower, or a leaf blower. Regardless of one's views on human-caused climate change, any rational person has to acknowledge that GA-caused air polution is a drop in the bucket of aviation-caused polution - which itself is a drop in the bucket of all human-caused air polution.

Electric airplanes? By all means, bring 'em on. But please don't feel entitled to righteously outlaw (or tax into oblivion) useful combustion-powered aircraft. Paranoia? Here in the People's Republic of Massachusetts, there are many who would seize my 27 mpg Corvette - and hand me a pair of roller skates. For their enlightened vision of my own good, of course.

I admire the technology, but deplore its emerging justification. It's the leaded-avgas crusade on steroids. Danger, Will Robinson...

Posted by: Tom Yarsley | February 19, 2016 10:22 AM    Report this comment

I don't believe in climate change, and I don't believe that pure-electric airplanes have a future other than training and toys around the local airport.

HOWEVER, I do believe that there is a future for hybrid aircraft. While most people tout the economy side (and the "true believers" tout the "climate change" issue)--the overlooked value of a hybrid system is in power redundancy.

For years, people have purchased twins to obtain that redundancy--gladly paying the extra cost of fuel and maintenance for that redundant engine, along with the mentioned decreased payload. They even accept the requirement to maintain proficiency when one of those engines fails.

With a hybrid motor/electric system, your second engine is always online and ready, as the piston engine produces power for the electric drive. In the event of a loss of the piston engine--you can continue for a finite time on the electrical system. Once in cruise, it only takes about 22% power to keep an aircraft aloft. I think most of us would be happy to have a redundant system that would sustain flight for an hour or so. The combination of piston and electric power also can be used for improving takeoff performance by using both systems for initial takeoff and climb.

Consider a Bonanza-style aircraft with an automotive type engine in the 200 hp+ range (like the Diamond twins), with an electric engine in the 100 hp range. Use both for takeoff--the auto engine provides economical cruise. In the event of an engine failure, the electric engine will still provide an hour to put you on an airport--WITHOUT the asymmetrical thrust issues. It provides the redundancy of a Baron with much more economy of fuel and maintenance- perhaps a BETTER useful load than the Baron--and the safety of one propeller.

Look at the weight of the drive system/batteries of the latest Prius--not much difference than the weight of two I0-520s and props on the Baron (not to mention the fuel efficiency--you wouldn't need to carry as much fuel).

These are REAL WORLD attributes for building i hybrid drive--not something based on unproven science or what governments MAY require. Pipestrel is covering all of the bases--I predict the hybrid drive will be the winner.

Posted by: jim hanson | February 19, 2016 10:40 AM    Report this comment

It really is unkind to Mr. Rutan to encourage folks to dig up his embarrassingly unscientific presentation from 4 years ago. As someone who learned to fly well back in the last century, I couldn't agree more with Mr. Bertorelli's statement, "We're long past due for thinking in GA not bounded by the established values of people who learned to fly in the last century." I have no idea whether hybrid or electric airplanes ever become more than curiosities, but I find the efforts to develop them exciting and welcome Mr. Bertorelli's level-headed reporting of it all.

Posted by: Robert Davison | February 19, 2016 10:49 AM    Report this comment

I'd compare this to the hybrid start in the auto sector. When the Prius came out, competitors (notably GM, which actually made an EV car), thought it wouldn't sell because the economics made no sense. The extra price tag on the Prius meant you had to own it for 5+ years before you saw the savings from lower gas bills. BUT the Prius was a huge hit for Toyota-- why? because people wanted to be the first on the block with a new, cool technology car. That segment is smaller in aviation, but there will be first movers who want in-- and that ultimately propels (excuse the pun) innovation

Posted by: andrew schmertz | February 19, 2016 10:54 AM    Report this comment

The current state of electric/hybrid technology harkens back to convetional airplane development in the 1930's. Lots of promising designs, lots of activity, but great uncertainty about where it would all lead. The thing is that it took World War II to provide the impetus to advance technology. During the war, cost was removed from the equation and companies went alll out to bring performace to the highest level. One wonders what will be the driving force today.

However, it seems to me that all this ignores the elephant in the room: What are we doing about advancing the technology of our current internal combustion engines? Comparing a "modern" aircraft engine to a current automobile engine is almost embarrassing. My 260 hp six cylinder auto engine can get 35 mpg on the highway at 70 mph while pulling a two-ton car. On a good day, my airplane engine barely makes 15 mpg pulling 2,800 pounds through the air, granted, at twice the speed. But, there are a multitde of obvious improvements that could transfer between the two if only those pesky regulatory hurdles weren't there. If the cost of updating conventional design is so great, what makes us think that electrics and battery technology will be remotely affordable?

Posted by: John McNamee | February 19, 2016 11:18 AM    Report this comment

Jim, here's some numbers to chew on that cause me to believe the aircraft hybrid concept isn't quite slam dunk.

The HYPSTER project Pipistrel is working on will be installed in the same airframe that will also have available a 260-HP Lycoming IO-540. The hybrid version has a 115-HP Rotax 914 driving a generator, plus 100 KG of batteries at 110 wh/kg. That means the hybrid can takeoff with the same or more available thrust than the Lycoming, but the batteries are depleted at TOC. If further climb is required, it will be on about 100 HP and that will be the cruise power, too. (Remember, the batteries have to be recharged, so you can't use the hydrocarbon engine's full potential.)

At mid-altitudes, the Lycoming can generate 170-HP or so (65 percent) for a 190-knot cruise. But the hybrid will have only 100 HP available or the equivalent of the Lycoming at 38 percent power. That's a big hit. Irrespective of cooling drag, I think it's going to be a lot slower, as I stated above. But with turbocharging, it can climb into the high teens and get some of the performance back. It almost has to do that to be competitive.

So the unknown equation to be solved is this: Will early adopter buyers not care about speed and climb rate and be more attracted to the dual-power capability in the way that Cirrus buyers are attracted to the parachute? Will they not care that payload will be less--about 120 pounds--than in the gasoline model? My guess is some buyers won't care and will go for the hybrid. Whether it's enough to sustain the idea, no one can say.

As conventional gasoline cars have become more efficient--a lot more--hybrid car sales have stalled. Aircraft gasoline engines won't make the same efficiency gains, although the diesel models are already very efficient. Diamond's new hybrid, by the way, uses a diesel engine and predicts about 120 knots on under 2 GPH. But it will carry 440 pounds of batteries.

Posted by: Paul Bertorelli | February 19, 2016 11:31 AM    Report this comment

The reasons electric airplane development is happening in Europe rather than the US are:

(a) fuel prices (gasoline and avgas are absurdly expensive there)

(b) the European authorities' willingness to consider certifying an electric airplane.

To point (b), the FAA simply does not know what to do with an electric airplane. For example, an electric airplane doesn't use fuel or oil, so it can't comply with the regulations on fuel and oil systems. But since it can't comply, it can't be certified. There's no engine-driven generator to power the electrical system (sorry, thermodynamics trumps that one), so the airplane can't comply with the regs and can't be certified. And so on. The FAA is entirely unwilling to consider things that don't at least partially fall under the current regulations--it's inconceivable to them that a small airplane might not use a gasoline-fueled magneto-ignited piston engine, and the regs are pretty much written to only allow that configuration.

Posted by: Robert Gatlin-Martin | February 19, 2016 11:31 AM    Report this comment

The niche for electric airplanes will likely be hybrids that have V/STOL capabilities. Small electric motors can be placed anywhere on the airframe. So for a vertical takeoff use the combined electrical power of the batteries and a gas-powered generator -- only a few minutes of high power are necessary. Then transition to just the gas-powered generator powering the electric motors for horizontal flight (while perhaps recharging the batteries in flight).

Posted by: DAVE PASSMORE | February 19, 2016 11:39 AM    Report this comment

John, the argument that airplane engines could/should be more efficient is perennial. But consider this: a Continental IO-550 running lean of peak is at a BSFC of 0.38 to 0.40 pounds/hp/hr/ That's pretty efficient and it's hard to imagine where you're going to get much more efficiency. Direct injection and variable timing might eke a few more percent out of it, but perhaps not commensurate with the investment to get there.

Car are different. Way different. The duty cycle is far more variable, the power required for cruise is far less because they don't suffer the aerodynamic penalty of going 150 MPH as airplanes do. Further, the volume supports rich research budgets so you see things like stratified charge, variable valve geometry, electronic fuel injection and throttle by wire. An airplane engine company chasing that on a volume of 1500 new engines a year would soon go broke, even if regulation weren't involved.

Posted by: Paul Bertorelli | February 19, 2016 11:43 AM    Report this comment

Lets not lose sight of the fact that the government has subsidized hybrid and electric cars. With out the socialized incentives, where would they really be today? I think that the electric/hybrid aircraft development programs are a good thing as there will be a few winners and some losers. If the government keeps its nose out of the market, then the true winners will arrive and thrive. Also remember that government intervention usually ends up killing other great ideas.

If the government decides to back hybrids, most effort will be directed toward hybrid R&D. However, without government intervention, some company may decide to develop another technology that may just become a winner. Fuel cells, hydrogen fuel, dilithium crystals, or temporal flux capacitors? Let creative minds run wild.

Junk science and manipulated data aside, climate change is a given. It has been so long before homo sapiens emerged from the trees to walk upright across the planet, and it will be with us long after government bureaucrats decree the cause de jour. I for one would be thrilled to get the lead out of our av gas. I am old enough to remember cars with leaded gas, doing valve jobs, constantly cleaning spark plugs changing out exhaust systems and marveling at an engine that lasted 100,000 miles. Today, thankfully that is all in the rear view mirror. We will be much better off with no lead av gas of some sort. Then what will the climate alarmists have for their cause celeb?

If electric airplanes end up only being useful for training or toys, so be it. Some riders like Harleys, some riders like BMWs and some riders like trikes. It will be nice to have the same kind of choice for airplane power systems as long as the government doesn't re-allocate my money to their chosen "winner" technology. If it can safely slip the surly bonds, and return to terra firma, let the market decide.

Posted by: Leo LeBoeuf | February 19, 2016 11:58 AM    Report this comment

Paul--"The HYPSTER project Pipistrel is working on will be installed in the same airframe that will also have available a 260-HP Lycoming IO-540. The hybrid version has a 115-HP Rotax 914 driving a generator, plus 100 KG of batteries at 110 wh/kg. That means the hybrid can takeoff with the same or more available thrust than the Lycoming, but the batteries are depleted at TOC. If further climb is required, it will be on about 100 HP and that will be the cruise power, too. (Remember, the batteries have to be recharged, so you can't use the hydrocarbon engine's full potential.)"

You are correct--there is little to be gained in performance or efficiency by simply replacing a piston engine with a hybrid drive--but that wasn't my point. My point is that replacing the TWO engines and props in a conventional twin (Baron, for example) with a single piston engine plus electrical engine and batteries DOES provide multi-engine redundancy in a simple-to-use hybrid package. Measure the fuel cost, efficiency, engine/propeller cost of the hybrid against the cost of an equivalent TWIN--and it looks much better.

I used the Bonanza/Baron analogy because they are similar airframes. My C-model Baron had a useful load of nearly 1900#. Cutting the weight of another engine an prop--accessories, cowling, and exhaust is nearly another 700#. You could almost lift a proven Prius (or other automotive) package intact--still leaving a good useful load (never mind the weight savings of an optimized aviation propulsion system).

The prize is not in PERFORMANCE, in ECONOMY, or "saving the planet." The selling point for this airplane would be multi-engine REDUNDANCY with the hybrid with diminished operating cost (overhaul, fuel burn) and EASE of OPERATION. If a hybrid could use automotive components (auto conversions have not generally been successful due to differing operating environment in airplanes, but the hybrid mitigates those differences), that would be a bonus.

I agree that replacing a piston engine with a hybrid by itself makes little sense, but if that "hybrid Baron" only produced Bonanza speeds while continuing to provide multi-engine redundancy--that's OK with me. I'd rather have that system than a parachute--but that parachute has sold lots of Cirrus airplanes. I'd like to see someone give it a shot.

Posted by: jim hanson | February 19, 2016 1:30 PM    Report this comment

"Then what will the climate alarmists have for their cause celeb?" They've already anointed one: carbon dioxide. Yup - the stuf that we exhale and that plants inhale. The human-caused climate-change faithful have staked out the proposition that ALL entrained carbon (a.k.a. fossil fuels) must remain entrained - a current-levels closed-loop system. I fear that GA emissions are a symbolic threat to that nirvana eco-paradigm.

Posted by: Tom Yarsley | February 19, 2016 2:19 PM    Report this comment

I saw your point, Jim. What I am saying is that the safety/redundancy aspect may or may not offset the slower speed, lower payload and higher cost among enough buyers to make a business out of it. Pipistrel thinks the Panthera Hybrid will be about 15 percent more fuel efficient from A to B. It won't be cheaper than the gasoline version and may cost a little more.

And it can't be a Bonanza-type airframe or even a Cirrus. To work, these airplanes will have to be very light and very slick, in the same way that a Prius looks the way it does for one reason: drag reduction. The airframes hybrids will work with haven't been invented yet. Diamond is using a DA40, but it's POC only. Look at the Airbus E-Fan 4.0 as a possible example.

Posted by: Paul Bertorelli | February 19, 2016 3:07 PM    Report this comment

There are two common types of hybrid drive; series and parallel. Most cars use parallel (for example both electric engine and internal combustion engine can be used together for traction) that combines both engines mechanical outputs through a differential-like gearbox. Then there are series hybrids like used in railroad locomotives that simply have the internal combustion engine driving a generator that charges a battery that powers an electric traction motor (i.e. all connected in series).

The HYPSTER described above sounds like a series-type; whether you use series or parallel architectures has a huge impact on instantaneous power available and overall capabilities.

Posted by: A Richie | February 19, 2016 3:29 PM    Report this comment

'More than once I've heard people in this field say words to the effect that at this point, we don't even know what we don't know.'

Good thing that couldn't possibly apply to something like the scientific study of earth's air, land and oceans and man using them as toilets. No future unknowns there.

My wife's '01 Honda Insight is of the parallel type of electric motor assisting the 3 cyl engine. The thing is fast, light, nimble and fun. 600+ miles on ten gallons of fuel. If someone could make a similarly well-engineered design as a 2 place hybrid aircraft, seems to me it would have a place in the market. Millennials generally love the car and the engineering involved, that might say something about the future of electric and hybrid aircraft, too.

Posted by: David Miller | February 19, 2016 6:44 PM    Report this comment

What the heck is the point of heating up the earth's atmosphere wasting time and energy talking about pure electric or hybrid GA airplanes vs "20th century" pure fossil airplanes? It's ridiculous. And bragging about inventing an electric supersonic airplane ... is Elon Musk insane?

YAR's comment is succinctly ON point ...

Even if you believe global warming is real and is man caused and the "end" is near (I don't), then attacking the largest area where a difference could be made would seem to be prudent, no? If we were all in the AZ biosphere, should we be worried more about someone who passed gas or someone who started a bonfire inside of it?

There are 255 MILLION autos in the US and 1.2 BILLION autos in the world. By 2035, they're predicting 2 BILLION autos worldwide. In 2013, DOT (now that they have us re-registering our airplanes) says there are about 200,000 US GA airplanes and 7,000 air carrier airplanes. Most GA pilots I know don't fly 100 hours per year yet drive their vehicles many times that. Airliners are flying many orders of magnitude more hours and each throughputs many more tons of exhaust per hour than the average GA airplane spews in a year ... maybe decade? There are almost four orders of magnitude more cars than GA airplanes. There are 60 times more recreational boats than GA airplanes. The methane passed by cows is likely a larger 'issue?' So who cares what sort of energy we use to enjoy or travel in our GA airplanes once in a while? Like Hillary says, "What difference does it make?" A hill of beans, at best.

An electric airplane STILL has to get its energy from ... somewhere !! So how does polluting the planet at the generating plant instead of coming out of an exhaust pipe make things better? Until battery efficiency reaches the point where a 300 pound battery (weight of 50 gals avgas) being recharged by a nuclear power plant can run an airplane for four hours, it's a complete waste of time to be even considering an electric airplane as being a replacement.

The Rotax 912is engine is about as refined an engine as there is for small airplanes. Why not just invent a modern day aerodynamically slippery C152, stick one in it fill it full of autogas and move on? Built in quantities on an efficient production line, their price would come down, we could stop moaning about $800K Mooney's and live happily ever after trying to keep the AOA in the green arc.

Anyone who thinks that a pure electric or hybrid airplane should be pursued as either a logical progression of technology or a way to save the planet is ... well ... eco-UNconscious due to drinking the green koolaid so far as I am concerned.

There's a BIG difference between energy conservation and energy efficiency. Carrying around batteries in a GA airplane, installing an aux engine to charge them or installing 16 electic motors on a Technam twin compared to carrying a tank of fossil fuel and getting on with it is a waste of time and energy inefficient.

The people who badmouth cars as causing Greenland's ice sheet to melt oughta be thinking of what the planet would be like if there were 2 billion horses moving us around on the planet. We're talking about the trees and forgetting the forest here, boys.

Now then, my Z06 and O-320's beckon ...

Posted by: Larry Stencel | February 20, 2016 7:18 AM    Report this comment

Paul, yes you are right; cars and airplanes are different. I don't mean to suggest an airplane engine would ever approach an equivalent mpg rating. But, if changing one of my mechanical mags to an electronic ignition system will yield about 10% lower fuel consumption (several friends report such savings), it seems that there are some reasonably priced items we could borrow from the auto industry. In talking to vendors of electronic ignition systems at trade shows, they all express frustration at how cumbersome (and expensive) it is to gain FAA approval for each engine they seek to add to their approved list. One would assume that the FAA would be willing to expedite the process, but that is an argument for another day.

To your point, if Lycoming and Continental can't justify the R&D for engine improvements at 1,500 units sold/year, then how can the electric and hybrid guys think they can do so? I doubt that they will sell more than 1,500 electric planes a year either.

Posted by: John McNamee | February 20, 2016 11:16 AM    Report this comment

Larry, your comment " ...thinking of what the planet would be like if there were 2 billion horses moving us around on the planet." kept me awake all night.

Posted by: Rafael Sierra | February 20, 2016 11:19 AM    Report this comment

RAF, going back to the dark ages and gettin' around on hayburners is one end of the spectrum. The other is trying to convince us that an electric or hybrid airplane will magically help the planet. John McNamee's comment is -- essentially -- saying the same thing, too.

In the small quantities of engines employed either in brand new GA airplanes being produced OR in ALL GA airplanes world wide, all that can be done is to make them more efficient. THAT would help some. We can do that aerodynamically and/or thermally. But that would require a willing bureaucracy in DC.

Rarely does anyone recognize that an airplane is a little bit like a rocket in Physics 101. At takeoff, it's heavy. Through flight, it gets lighter ergo more efficient. An electric or hybrid airplane doesn't do that. Electrons moved by a battery don't weigh much less at landing. What a revoltin' development at the Cunninham Aircraft Factory, I say ! Where is Elon when we need him?

Maybe we oughta petition the alphabet soup organizations to get the FAA to get off their butts and certificate the now available electronic ignition systems as an amendment to HR 4441. Yeah, right. The Administrator would have to stand up at Airventure and tell us how "it's at the DOT." (Again!).

Just remember, California has catalytic converters on it's gas lawnmower engines and electric lawnmowers (that get recharged from someplace in Arizona) so everything be A-OK in Palm Springs! Sleep easy tonight, RAF.

Posted by: Larry Stencel | February 20, 2016 12:07 PM    Report this comment

"To your point, if Lycoming and Continental can't justify the R&D for engine improvements at 1,500 units sold/year, then how can the electric and hybrid guys think they can do so?"

I don't think the business cases are any better for electrics than for new piston engines, at least for the short term. Even the long term is a risk. In Airbus' case, they see some kind of electric propulsion as inevitable along a 30 to 50 year time line and are willing to invest now to gain the fundamental certification and technical experience. Boeing is doing its version of the same thing. (See the Sugar Volt project.)

If you look at broader trends for future power plants in general, that makes as much as imagining hydrocarbon engines will somehow become significantly more efficient than they are now. The same doubts existed in the early days of jet engines, when some predicted materials would never be durable enough to make engines that would last for even 50 hours. But progress marches forward and technical barriers were overcome.

It will be interesting to watch the same progress in electrics. I seriously doubt if this is dead end technology.

Posted by: Paul Bertorelli | February 21, 2016 5:23 AM    Report this comment

By the way, the link to Tamino's Wordpress piece above doesn't seem to work. This one is correct.

www.tamino.wordpress.com/2012/01/29/some-questions-for-rutan/

Posted by: Paul Bertorelli | February 21, 2016 3:51 PM    Report this comment

Boeing and Airbus e-plane is good investment in "green" PR. A long shot in socially acceptable technology. A noble idea, kinda recycling C172s.

Posted by: Rafael Sierra | February 21, 2016 6:46 PM    Report this comment

Raf: If wishes were dragons, greenies would fly. Pigs, too. ;-)

Posted by: Tom Yarsley | February 21, 2016 9:12 PM    Report this comment

Good article, but reporter needs to get out and talk to all the different electric flight demonstrator efforts - as he doesn't seem to be aware of the current NASA SCEPTOR distributed electric X-Plane. That effort is showcasing that electric doesn't need to be slow to be efficient, and that you don't want to merely retrofit electric to an existing airframe. Look at the first turbine aircraft and you'll see the same thing - when a radical change in propulsion technology occurs, the airframe wants to change as well.

Several insight points made in this discussion; however, the big picture seems to be getting lost because of some myopic near-term perspectives. Yes batteries are improving at 7% per (have been for 30 years, and likely will be for the next 30 years). Right now we're at 250 Whr/kg energy density, so it 10 years we'll be at 500 Whr/kg. Through the NASA Green Flight Challenge we proved we can do 200 mile ranges at 108 mph with simple retrofits (5 years ago). With SCEPTOR there's no question we'll prove we can improve efficiency of a Tecnam P2006T by 5x at 150 knots with distributed electric propulsion. Within 10 years we'll have aircraft that can fly pure electric 400 miles, which is good enough for most GA flights. Put it this way, what's the rate of increase in specific energy of gasoline?

There are so many improved characteristics relating to electric flight that the nay sayers should take a breath and hope that we can quickly transition this technology to certified products. As pointed out, in particular the opportunities for a new breed of feasible VTOL vehicles which are highly redundant and efficient is a wonderful fit for this technology - and will be shown in the near-term. The preponderance of evidence is that electric flight will take place over the next 20 years - study the issues and there is no other conclusion possible - but it will take time. As to the the carbon argument - at some point we will have to transition to renewable energy - encouraging this transition sooner is simple common sense and goodness for everyone (and everything) on the planet.

Posted by: Mark Moore | February 22, 2016 10:28 AM    Report this comment

Thanks for the comment, Mark. But to be fair, you should identify yourself. Mark is a principal investigator at NASA studying electrical propulsion.

And I believe you're quite aware that I know about Scepter and LEAPTech because you and I discussed these projects. I didn't happen to mention them here because this is short blog focussed on near-term actual airplanes.

Posted by: Paul Bertorelli | February 22, 2016 10:54 AM    Report this comment

I can see electric 'revolutionizing' the ultralight arena if the (ridiculous) weight penalty/limit is modified.


Maybe electric makes sense for ultralights?

Posted by: Peter Kuhns | February 22, 2016 11:14 AM    Report this comment

How is SCEPTOR not a "near-term actual airplane" - it'll fly in 2017 and is a clear indicator of what's to come, and why electric aircraft need to be redesigned from the onset to take advantage of electric flight. Why would anyone even discuss a radical new technology in terms of near-term applications only anyway? Any breakthrough technology takes 20 years to take hold - imagine writing about ARPANet 20 years old and only discussing near-term applications... I understand a short blog over simplifying the issues - but to completely overlook the main issue that most efforts to this point have only retrofitted electric propulsion is a huge oversight. Electric propulsion has such completely different characteristics that it's rather insane to think that simple retrofit applications are going to permit "faster, further, higher". Electric aircraft naturally want to fly at higher altitudes because they don't lapse power with altitude - so what many people don't understand is that electric flight will naturally want to be faster and higher than conventional GA aircraft. Again, thanks for a good article - but if you are aware of all that's going on in electric flight demonstrators, then this article missing much bigger vision of what electric will be capable of achieving.

Posted by: Mark Moore | February 22, 2016 11:42 AM    Report this comment

Prior to January of this year, I would have discounted electric cars and electric airplanes. I just didn't see the reason for either. Then in January, I had a chance to spend 3 weeks with a Tesla. I have to say it changed my opinion. Yes, the Tesla has limited range when compared with piston engine powered automobile but it has other advantages which make it desireable. The acceleration is fantastic and to get the acceleration, you don't need 500 HP. 500 HP comes a lot of baggage, weight, extra fuel consumption, etc. Pressing the peddle to the floor results in an immensely satisfying surge without all the dramatics of a piston engine. Also, you periodically get new features such as summons mode via software download. This keeps your car fresh. Of course there is autodrive mode which is beyond anything else on the road. Despite the range is a limitation, the other aspects, comfort, no gas required, tech, etc, that make the Tesla desirable. I believe this is the same for electric airplanes. There will probably be other features that make electric aircraft desirable beyond just the range limitation. It may be easier to fully automate the flying experience with an electric motor that with a piston engine for example.

One thing the FAA could do is to change the part 103 regulations so that batteries can be included equation. It seems to me that electric aircraft is perfect for an evening flight down the beach!

Posted by: DANA NICKERSON | February 22, 2016 11:47 AM    Report this comment

The Tesla is a wonder in California, but it will barely get you out of the parking lot when it's ten below zero here in New England. Seriously, around here you'd be crazy to take any car out into a winter storm without having a reliable means of providing life-sustaining cabin heat for an interval of at least 12 hours. Caveat emptor, just sayin'....

"Electric aircraft naturally want to fly at higher altitudes because they don't lapse power with altitude." True enough, but they will need to account for the not-insignificant increase in electric demand imposed by pressurization, cabin climate-control, and airframe and windscreen anti-ice / de-ice systems - electric variants of which will have to be developed and certificated.

The hybrid approach is akin to having an extension cord to power your electric bird in flight, and the combustion engine's waste heat can be put to good use, too.

Posted by: Tom Yarsley | February 22, 2016 12:20 PM    Report this comment

'I understand a short blog over simplifying the issues - but to completely overlook the main issue that most efforts to this point have only retrofitted electric propulsion is a huge oversight'

Not that Paul needs my defending, but I don't see him as one over simplifying the issues. On these blogs you have some readers wanting the wonkiest view of a subject and others who just want information on how to keep affording to fly occasionally and maybe believe it's part magic. It is, isn't it?

You're missing the bigger view, imho, of a broader consideration of the varied states of consciousness of the readers by thinking he's simplifying subjects for them. Cattle prodding comes to mind more often than simplifying does to me. :)

Since SCEPTOR is guaranteed to fly in 2017, I'm sure it will be mentioned more than once as the date nears on these hallowed threads. We'll all be watching, and thanks for the good work toward cleaner energy use for us and our planet.

Posted by: David Miller | February 22, 2016 1:27 PM    Report this comment

I suppose SCEPTOR is a real airplane and not conceptual. But on the other hand, it's real the way the X-15 was a real airplane. It's a research vehicle, unless I missed something and it's going into production. Our interest here is necessarily short term because our readers are most interested in things they might immediately be asked to buy, such as the E-fan 2.0 and 4.0 and the Pipistrel hybrid or the Alpha Electro. Even those are aspirational.

In aviation, we have seen so many ideas run off the rails due to over promising that a little skepticism is not just a good idea, but a survival instinct. And of course, we've been around the houses with NASA before on the AGATE and SATs programs, neither of which bore lasting fruit, especially AGATE. It was sold as GA revitalization and I suppose one could argue that as industry, we would be dead without it, but revitalized we ain't.

Electrics will be a difficult transition for manufacturers because they'll have to invest heavily with no promise that this technology will be disruptive enough to flow sustainable profits into the enterprise. Without that, electric aviation in our little end of the market will be a slow starter indeed, unless there's some economic force on the horizon that will change that. I don't see it. And no one else has described it, either. Still, I'm convinced it will come.

I suspect it will look different in a decade, but not sooner than that. That's what people outside of general aviation, including the popular technical press, don't get. Macro economic trends in GA are so unfavorable that even electric airplanes that cut direct operating costs by half or more seem unlikely to put much of a dent in it.

When there's a flyable version of SCEPTOR or an airplane like it, I'll be the first to sign up for a trial flight. So far, after months of begging to get my mitts on an electric airplane, it's only happened once.

Meanwhile, some links to provide good background.

www.aero.larc.nasa.gov/files/2012/11/Distributed-Electric-Propulsion-Aircraft.pdf
www.nasa.gov/centers/armstrong/Features/leaptech.html
www./nari.arc.nasa.gov/sites/default/files/MooreSeedling.pdf

Posted by: Paul Bertorelli | February 22, 2016 1:38 PM    Report this comment

Good points that are fair enough - however, did you REALLY mean to say that AGATE didn't bear any meaningful fruit? I think it's fair to say that about GAP (the General Aviation Propulsion project) or SATS - but it's not fair to say that about AGATE. How about the AGATE composites handbook, Lightening Strike handbook, and flat panel display certification. Guess where all that came from? AGATE was imperfect, but an incredibly effective investment IMO, and GA would have been dead in the waters in composites and avionics if not for that public-private research. I had no involvement with AGATE, so I don't feel that I'm being biased. But 100% agree, healthy skepticism is a virtue in engineering - but if we apply that to every investment decision to be made - we won't get any new technologies developed to improve the future. Again - thanks for creating a great discussion. I'll get off my soapbox.

Posted by: Mark Moore | February 22, 2016 3:02 PM    Report this comment

Thank you and watch your step.

Posted by: Rafael Sierra | February 22, 2016 4:43 PM    Report this comment

I spent 15.5 years of a 21 year USAF career working flight test at Edwards AFB. Thereafter, I spent 12 more indirectly tied to it working on a big black aeroplane that lived there, too. So I'm intimately familiar with what happens at the north end of the contractor's row -- aka NASA. Rogers dry lakebed is littered with taxpayer funded goofy ideas that never went anywhere and aviation has a few success's that came from there, too. So I guess I'm saying that I see merit in both sides of the most recent discussion.

I was there just after NASA pulled an early lifting body with a Pontiac 421 V8 and then a C-47 before dropping a bevy of different designs from 'Balls 8..' That effort turned into a Space Shuttle without an engine in its tail. More recently, someone decided to pull an old F-106 with a C-141 and no USAF type would fly it. So pure research for research's sake is good. But, believing that each goofy idea that is tested will spawn a generational paradigm change is just as nutty. When money is "free," why not at least try. New streets at Edwards need names, don't ya know.

There's probably a place for an electric powered airplane that'll work on an exoplanet with some sort of atmosphere that doesn't have a nearby Sunoco avgas station handy but unless and until battery technology achieves several orders of magnitude of energy density improvement, all we're doing is spending money and not much else to keep aero engineers employed. Maybe a flight school could start up at Barstow-Daggett and recharge each morning from the mirrors out there.

Now then ... I'm off to the hangar. I hear mounting 16 electric motors on my C172's aero-elastic wing will make it mucho more efficient AND save the planet and the ice cap, too.

Posted by: Larry Stencel | February 22, 2016 8:50 PM    Report this comment

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