Electric Airplane Ready For Production

MrSeb writes with news about a production ready electric-hybrid airplane. From the article: "... The four-passenger carbon fiber aircraft isn't really an electric plane but more of a plug-in hybrid plane, much like the Chevrolet Volt. Whatever it is, the Volta Volare aeronautics company of Portland, Oregon says the plane can travel 300 miles on battery power, then a 1.5-liter gasoline engine engages and extends the plane's range to 1,000 miles. The company sees the plane being attractive for its low cost of operation and its environmental friendliness. Aviation gasoline is typically leaded fuel, which has been gone from motor vehicle fuel since the 1980s. On a 200-mile trip in a comparable four-passenger gas-engine private plane, you'd burn $80 worth of avgas, while the electricity to carry the GT4 200 miles would cost only $20 — nice savings, but perhaps a little inconsequential when the plane itself is expected to cost around $500,000. Testing begins this spring on the Volta Volare GT4."

Comments

If you're going to crash

[Ukab the Great]

Do you have to divert power from life support?

Re:If you're going to crash

[Sperbels]

Shut up, Wesley. That would take weeks of laying out new circuits.

Solar

[SJHillman]

Could you increase the range by mounting solar panels on the body of the craft? It wouldn't be enough to keep it flying indefinitely, but it might slow the rate of drain on the batteries.

Re:Solar

[jaymemaurice]

I'd think that depends on the weight of the solar panels... they'd have to be more efficient then the cost to carry them. And I'm sure light panels would not make this $500,000 plane any cheaper.

Re:Solar

[Ol Biscuitbarrel]

How about having the prop double as a wind turbine? Then you could fly forever. I'm always telling people about how we could just mount turbines on the roofs of cars and power the engine; they're inevitably enthusiastic about this idea. /sarcasm

Re:Solar

[icebrain]

There are several problems, though.

First, certification is expensive, not just due to the paperwork (lots and lots and lots of paperwork) but also due to the regulations being overkill for light airplanes--they're geared more for heavy, complex aircraft like airliners, King Airs, business jets, and so on.

There are also liability concerns. Decades-old designs have some level of exemption from liability in civil suits, but new designs put the manufacturer at risk of silly lawsuits (even when they are in no way at fault, like a pilot flying into weather he isn't rated to fly into).

On the technical side, you can't just take a car or snowmobile engine and substitute it in for an aircraft engine of the same horsepower. Airplane engines are designed to produce 75-100% of their rated power indefinitely; most car engines cruise at a much smaller fraction of rated power. Try running your average car engine at 85% power for hours on end, and it won't last nearly as long.

There are also other issues like maneuvering and gyroscopic forces; not only are aircraft likely to experience more variation in g-forces from turns and aerobatics, but there are also thrust and gyroscopic loads from the propeller to worry about. Running a reduction gearbox simply means your gearbox has to take those loads instead, presenting additional challenges.

These problems are not insurmountable--they just take time and money. But right now, the market just isn't there. General aviation sales are tiny compared to car sales, so your R&D costs would have to be spread over far fewer units--driving price up and sales down. That's why progress in the area of small aviation piston engines is very slow, and it's why Lycoming et al are still making engines based on 1930s designs.

Re:Solar

[tlhIngan]

This is not your father's leaded gas. It is 100 Octane Low Lead gas. It is pretty expensive because it is in relatively low demand and so many refineries just do a batch once in a while, and it keeps getting more expensive because more and more refineries consider it not worth the effort.
 

In North America, there is ONE refinery still producing it. And they pretty much only run a batch once a year - an entire day's production is sufficient for an entire year. Something like all the avgas used in a year is equal to all the regular gas used by cars in a day.

And the reason most refineries don't do it? They need special equipment - the equipment handling leaded fuel must be separated from the normal unleaded stuff. And there is only ONE company in the world licensed to handle tetraethyl lead (the lead in leaded gasoline), and they're in the UK.

If it wasn't for the importance of GA and small planes for the economy, it really would be uneconomical to continue producing leaded avgas. (And yes, GA is important - for every idiotic CEO asking for a handout from their multimillion dollar jets, there are hundreds more middle-income people flying for fun/recreation as well as business in little single engine Cessnas and Pipers. Even more with some very neat Light Sport aircraft...).

Small aircraft engines are decades behind automotive engines in terms of technology. Fuel injection and particularly computer controlled fuel injection are relatively new in small aircraft engines. Some of this is to blame on the immense cost of certification. If you have an engine that works and it will cost 45 million to certify a new engine with new technology and you are going to take X years to make up the cost, then it may not be worth the money and time.
 

The problem with aircraft engines is that they're expected to deliver rated power continuously. Car engines don't - that 450bhp monster under the hood of that muscle car would probably break down if you tried to run it at 75+% power for hours on end. It just doesn't take much horsepower for very long to get a car moving and keep it moving down the highway.

And yes, certification is an issue - a lot of promising technology comes from the experimental aviation sector - homebuilts and such - because a lot less certification is required.

Annuals

[vlm]

How do they handle annual inspections? Replace the battery pack every year?

On a 200-mile trip in a comparable four-passenger gas-engine private plane, you'd burn $80 worth of avgas

Who cares, annual inspections for a small plane, assuming no real problems are found, are like $1500 ... every year ... and hanger rental monthly nears the cost of renting a bachelor pad apartment (which makes sense, they're about the same size...)

The standard /. car analogy is its like making economic decisions about buying a Lamborghini primarily based on how much the windshield washer fluid is likely to cost. If you're sweating the cost of fuel, there is no way you can afford the other much larger costs of aircraft ownership. Wait until your first landing light replacement, just like a cars headlight but it costs 10 times as much (because its aviation) and is only rated at a fraction of the lifetime of a car headlight. Insurance is quite expensive too. You may find the cheapest cost of owning an aircraft... is the fuel.

Re:Annuals

[SJHillman]

No, hanger. He puts his plane in his closet next to his other clothes.

Re:Annuals

[Doctor Memory]

How did you figure that out? Are you a plane/clothes detective?

Re:Annuals

[Lumpy]

Ok, blowing all my moderation to correct some wild innacuracies here.

Hangar costs, Unless you are uber rich you dont have a hangar, but a parking spot / tie down either in the grass or if you are rich, on some tarmac. there are small fields all over the USA and Europe, in fact they outnumber airports 50 to 1 that will let you park your plane for around $50-$150 a month.

Annual inspections, $1500.00 Do you realize how much I pay for monthly inspections on my car? it comes out to far higher than $1500 a year.

I know people that make as little as I do that own and operate a 4 seater aircraft. Contrary to belief, private aircraft can be affordable and safe. In fact most private aircraft are left outside their entire lifetime and only see a hangar when they are in for service like engine overhaul, wing replacement, etc... And those are the high costs you did not mention. You cant ignore a plane like 99% of all car owners do to their cars. The wings have to be replaced after XXXX hours, engine needs to be completely overhauled every XXXX hours... and those numbers are small, most around the 2500 hour mark.

Yes, AVGAS is the cheapest part of owning a plane. You can buy a Piper Warrior II that is in like new condition, pay for all maintaince, parking, service, upgrades, and AVGAS for 10 years for the price difference to this electric plane.

It's the same as comparing a honda civic to a Chevy volt. Identical cars, but you save nothing as the extra cost is more than the gas you would buy over a 10 year period. (and yes they ARE identical. I have parked them side by side and sat in both looking things over. the Volt is a honda Civic with fancy electric drive.)

Ahh No it isn't

[LWATCDR]

Wow what a load of fantasy.
1. They have not even built the prototype yet.
2. 300 mile range on battery? Not a chance.
Until they fly it at Oshkosh or Sebring and get FAA certified it is pure fantasy.
Rule one of general aviation is never get excited over a rendering or illustration of a new plane. 9 times out of 10 it will never see the light of day.

Some reality checks

[million_monkeys]

It's definitely cool to see this in development, but there's a lot of suspect claims going on. And of course no talk of the downsides of being electric.

The GT4 uses an array of 236 off-the-shelf lithium-polymer batteries weighing 900 pounds. The company says the battery pack and 600 hp (peak) electric motor weigh less than the internal combustion engine on a comparable plane,

so 900 pounds of batteries + ? pounds the electric motor (i guess we're ignoring the weight of the backup gas engine plus the 140 pounds of gas to fuel it) weighs less than the engine on a "comparable plane". Here are some planes and engines:

Cirrus SR22 (4 person, 180 knot cruise) engine: Continental IO-550-N (~450-500? pounds)
Cessna 182 (4 person, 140 knot cruise) engine: Lycoming IO-540-AB1A5 (~450 pounds)
Cessna 210 (6 person, 190 knot cruise) engine: Continental Motors TSIO-520-R (~450 pounds)
Diamond DA40 (4 person, 150 knot cruise) engine: Lycoming IO-360-M1A (~300 pounds)

Full fuel for most of them is would add ~550 pounds, so total ~1000lbs, barely more than the batteries alone on the electric one. It seems like they pulled this weight savings out of their ass.

Volta Volare says low maintenance costs will be a big attraction. The gas engine on a private plane needs an annual inspection that could cost several thousand dollars. In comparison, the GT4 could get by with a simple diagnostic checkup by laptop: Just plug in a USB cable to the electric motor.

Not in the USA it won't, at least if they want the FAA to certify it. I wish I could be there when they propose that just to see them get laughed out of the building. This is the same agency that will declare a plane unairworthy because it doesn't have a sticker saying what kind of fuel it uses. And again, they are ignoring the backup gas engine. Even if they let the USB thing slide, the backup gas engine's gotta be inspected just like every other gas engine. I'm doubtful of the massive savings they are implying

Some of the electricity-not-gasoline savings are nice but still dwarfed by the purchase price that is likely to be over $500,000.

That sounds like a lot, but new planes are expensive. The cost (new) of the planes listed above, not including various optional equipment:

Cirrus SR22: $600K-$700K
Cessna 182: $400K-$450K
Cessna 210: out of production, but likely around $550K-$600K
Diamond DA40: $350K