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."

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.

Re:If you're going to crash

[SJHillman]

It has two different power sources - batteries and an engine - I would assume either is capable of providing enough power for the basics on its own. I also don't see a plane this small flying at such an altitude that losing power would lead to loss of life support being a fatal issue before the pilot could descend.

Re:One benefit planes have over cars

[Richard_at_work]

As you said, it would be relatively pointless, but something to consider when thinking about it is this - fuel gets burned off, batteries do not.

A Boeing 747-8 can carry over 200 tons of fuel - at its destination, it could be carrying as little as 10 tonnes of fuel (or less). The more fuel that gets burned off, the higher the aircraft can cruise, and the longer it can fly because the lighter it gets the more efficient it is at producing lift.

So you would need a much more efficient battery system to counter the effect of still carrying all those batteries the entire distance of the journey - plus the effect of landing an aircraft that would still be at the Maximum Takeoff Weight (MTOW), which isn't great on the airframe (the Maximum Landing Weight is typically fairly lower than the MTOW, which is why aircraft in emergencies dump fuel or circle to burn off fuel).

In cars, the weight difference between a full fuel tank and an empty fuel tank is near enough negligible to be discounted, but in an aircraft its a real factor.

Re:Annuals

[RogueWarrior65]

Excellent point. My auto mechanic tells me that his hybrid customers refuse to spend $5000 to replace the battery pack when it goes tits-up and just run on gasoline.
For my own purposes, I've been learning a lot about battery tech. Hard core R/C modellers often have a computerized battery analyzer which allows you to plot the performance of the battery and keep a history because they degrade over time and number of charge/discharge cycles. A traditional engine can be repaired but batteries can't.

IMHO, the leaded gas issue is barely measurable compared to millions of cars spewing out lead in the exhaust which illustrates the extreme obsessive/compulsive behavior of the environmentalists. Separate issue, though.

As a matter of interest, Sikorsky has developed and electric helicopter. Apparently they use a Korean-made lithium pack with a 50S3P designation. That's 200 volts. Of course, they've only gotten about 15 minutes flight time so the project will sit on the shelf until battery technology catches up.

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

Re:Solar

[na1led]

It doesn't work. You end up creating drag which expends energy to make energy, that's why its only used on braking systems. Same goes for putting a turbine on the roof, the drag costs more energy than the turbine can produce. Sorry, but there is no free energy unless you get it from the Sun.

Re:If you're going to crash

[Anonymous Coward]

That seems short-sighted. Unless you can restore life support quickly after avoiding the crash, you'll find yourself suffering quite a protracted and distressing death. I'd take insta-death over asphyxiation any day of the week.

The agony of typical asphyxiation is caused by the brain generating a distress signal from being unable to aspirate. If you are aspiring normally, albeit with (ultra)low oxygen concentration levels, you will simply slip into unconsciousness due to hypoxia. Your body has no alarm signal to detect oxygen deprived environments, which is why carbon monoxide is so dangerous (besides the fact that haemoglobin binds to carbon monoxide more easily than oxygen or carbon dioxide).

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.