
All-electric trainer aircraft, cheaper than Cessna - vinnyglennon
http://www.techinsider.io/electric-aircraft-sunflyer-2016-5
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AdrianB1
The big problem with the small planes is not the engine and fuel (still can't
beat AVGAS in term of efficiency), but price; any part that exists in the
automotive industry gets a 3 time price increase if it is used in aviation, 5
times if it is certified. A 1.4 liter 4 cylinder engine with 100 HP, that
would be maybe 15-2000$ in a car, is ... 17.000$ for a small plane. A mobile
radio for aviation starts from $300, a fixed one from $1500. That makes me
believe the simple to maintain electric engine will have a 10 times price
increase when used in an aircraft, just because they can and also because of
all the crazy litigation system in US where 50% of the price of a new plane is
put aside to pay for future litigations. In Europe we have huge taxes, so the
price is even higher.

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cpncrunch
The FAA's Part 23 rewrite should help this. Just this month Dynon managed to
get their D10A EFIS STC'd even though it isn't TSOd. Basically we will be
allowed to put avionics designed for the experimental/homebuilt market into
certified aircraft, resulting in a huge cost saving.

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mdorazio
Does anyone have more specifics about the actual capabilities of the
prototype? I'm skeptical they're able to get 3 hours of flight time out of a
battery pack without sacrificing just about all the weight capacity for things
like... a pilot. It's great to see that companies are actively working on
electric-powered flight, though, especially in the small aircraft space where
it has high potential.

Also a small beef with the article - it makes it seem like there just aren't
enough pilots to fly commercial planes, which simply isn't true. There are
plenty of pilots, they just don't want to work for the terrible pay and life-
destroying hours most carriers are offering, while at the same time often
having to cover their own massive training costs. Some more info on the
situation: [http://time.com/4257940/pilot-
shortage/](http://time.com/4257940/pilot-shortage/)

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ams6110
Agreed, very little real information here. Nothing about range, top speed,
weight, etc.

A big part of training is doing "touch and goes" to practice approaches,
landing, and taking off (the most dangerous phases of flight) which I would
think would tax the battery a lot more than just cruising around for three
hours.

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yompers888
As someone who really would love to get into general aviation but finds the
fuel costs off-putting, I'd love for this to be successful. Isn't the big
problem with electric planes supposed to be the energy density per kg?
Wikipedia is showing 46MJ/kg for jet fuel, vs only ~1MJ/kg for lithium
batteries [1]. Is this a lesser concern than I've been led to believe, is
there recent development that improves lithium batteries by at least an order
of magnitude in this property, or are they using some different battery
technology entirely? I'm disappointed that there's no mention of the battery
tech.

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AdrianB1
Cessna takes about 8 gallons per hour to fly; if you want to fly at 3 gallons
per hour then go for any Rotax 912ULS plane, most are LSA but you can upgrade
the license to PPL adn the flight time on LSA (cheap) is considered for PPL.
In the end a Comko Ikarus C42 has similar performance with a Cessna 152 and a
Pipistrel Virus SW is lighter and much faster (+30%) than the 152 for less
than half the fuel consumption.

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walrus01
You can't buy a modern Pipistrel for th price of a 1975 Cessna. A huge % of
the light 2 and 4 seat aircraft out there in the c172 and smaller sizes are
25+ years old.

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AdrianB1
You are right, but that does not make it right to compare a new electric
plane's cost, flying performance and energy efficiency/consumption with a 1975
Cessna except if you have a time machine to send the electric plane back in
1975.

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walrus01
Except that 1975 Cessna is much, much more likely to be what a small flight
school/rental operator/FBO company can afford to buy. $35,000 and ongoing
maintenance vs $175,000+.

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Zombieball
My concern about training on an aircraft of this fashion is that you get no
exposure to controls such as carb heat, fuel mixture, etc.

I wonder if a distinction will be made (in the not so far future) between
getting rated on a combustion plane vs. electric? Much like you get rated for
high-performance or twin engines today.

~~~
sgnelson
Serious question from someone who knows very little about planes. Do they
seriously still have new carbuereuted planes? I can understand if it's a
Cessna from the 50's, 60's, 70's, but I'm surprised they haven't been
converted to EFI just from an efficiency and reliability stand point. Does
that have to do with all the certification required for aircraft? (ie, if you
change the engine, the aircraft has to go through another inspection by the
FAA or whomever?)

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Merad
The problem in general aviation is the cost. As the article mentions, even a
simple Cessna purchased new costs as much as a house. The result is that there
are a LOT of planes flying that date back to the 1940s, 50s and 60s.

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sgnelson
Very interesting. But sadly the article mentions the same old line: not enough
airline pilots. The truth is that the airlines are not willing to pay for
airline pilots. That's how capitalism works. You want workers? You pay
workers. Simple as that.

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pingec
What about this one: [http://www.pipistrel.si/news/wattsup-the-new-2seat-
electric-...](http://www.pipistrel.si/news/wattsup-the-new-2seat-electric-
trainer-took-its-maiden-fligh)

Not an expert - don't know if they can be compared and the article lacks any
actual specs to compare by, but the pipistrel's electric plane seems to be
much cheaper.

"Pipistrel expects to bring the final product to the market in 2015 with a
target price below 100,000 EUR."

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AdrianB1
50% of the cost of a plane sold in USA is put aside as reserves for
litigations; that doubles the actual cost of the plane, so the Pipistrel that
is sold in Europe for 100,000 EUR may be $220,000 in USA. The Cessna 172 is
300k; a modern Pipistrel with better flying capabilities is 100K (there are a
couple of 2015 Pipistrel planes on my base airport). Cessna does not sell lots
of 172's, but neither Pipistrel does not sell in USA at 100k. The aviation in
USA is mostly based on cheap old 1950-1970 planes, the cost for new is
astronomical.

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nkurz
Are you sure about this? I'm not in the market, and don't know the details,
but it looks like Pipistrel USA is advertising "Ready to Fly" prices
(denominated in Euros) that are much less than you say.

For example, the Sinus shows a base price of 78500 EUR, and the Alpha Trainer
Electro Experimental shows 110000 EUR: [http://www.pipistrel-usa.com/price-
list/RTF-price.html](http://www.pipistrel-usa.com/price-list/RTF-price.html)

Is there some large undisclosed fee that is added to this? Or do the "add ons"
actually required to have a flyable plane?

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DrScump
It seems like an obvious feature would be to have solar cells on the upper
wing surfaces... I guess the energy payout isn't sufficient for the area?

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dmd
That _might_ be sufficient to power half of the avionics (i.e., maybe 0.01% of
the power consumption. )

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sgnelson
I can't say anything to the power efficiency of solar cells, but I can see how
they could be useful for when you're not flying. "Free" energy for when you're
ready to fly if you don't fly the plan daily, but instead just fly on the
weekends or such. In the middle of nowhere without fuel or electric hookup?
Wait a few days and at leas the plane will have energy to fly out of there.
I'm not saying that will be the case, but an interesting aspect of solar
panels on wings.

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djrogers
You'd be much better off to simply have a few panels on a rack that you put
out next to the plane. Being forced to haul around the extra weight of the
panels on the top of the wings would be counterproductive, and if you really
wanted the panels with you one day, you could pack them up and take them with
you.

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joosters
I wonder how long the batteries will last for? Not the flying time, I mean
instead their useful lifetime. It might become extremely expensive if you have
to replace the batteries every year or so...

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DrScump
Then again, newer technologies resulting in better energy-per-unit-weight
could drive battery replacement sooner, anyway.

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TheIronYuppie
I know every one is talking about the energy density of gas, but wouldn't
there reduction in moving parts in the engine offset? How does a Tesla compare
to an average cat?

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qbrass
A Tesla's motor saves 200 lbs over a 4 cylinder engine but the battery pack
adds 1000lbs over a 12 gallon fuel tank which would allow you to drive that 4
cylinder car twice as far.

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peteretep
I was on a little Cessna Caravan twice this weekend, and both times was struck
by how much less the torque on them is than a Tesla...

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sokoloff
Early PT6-114s (the turboprop engine on the early 208s) have a takeoff torque
limit of 1658ft-lbs. Later PT6-114As (the current engine on the 208s) has a
takeoff torque limit of 1865ft-lbs.

The Tesla P85D has less than half of that.

The Caravan has much less initial acceleration than a Tesla, but far more
torque.

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sgnelson
my next question is: When will we have these small planes with true
autopilots, which would allow a true novice to fly them?

And surely people are working on them, but you don't hear about that as much
as you do automobiles. Anyone know anything about this?

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slavak
Probably not in the foreseeable future; the market just isn't there, and in
large part- the technology isn't either.

For one thing, the technology for truly automatic or nearly-automatic landing
(takeoff might be simpler) requires a lot of equipment at the airport, which
the vast majority of airports a hobby pilot would fly from will never install.
Since takeoff and landing are by far the most difficult and dangerous parts of
the flight, this pretty much automatically precludes the possibility of an
untrained pilot.

Add to that, the stance in aviation is that the pilot must be capable of
taking control of the aircraft if there is any problem with the automation. I
don't know the statistics, but presumably the sensors and automation by itself
are not reliable enough to function completely autonomously and without
supervision 100% of the time. And if you're gonna have a hobby pilot that is
perfectly capable of flying the plane manually, full automation is just a
massive waste of money.

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ams6110
_An electric powerplant with effectively one moving part should also have
dramatically lower mantenence cost than a traditional, gasoline-powered engine
of more than 1,000 components_

I see this sort of statement made about electric cars also, and I think it's
really not true. Modern internal combustion engines are very reliable, and
need very little maintenance. Yes they need oil changes every so often, and I
guess that's "dramatically" more in a divide-by-zero kind of way, but
realistically it's not going to make a huge difference in the operational
expense of a GA aircraft. Also not addressed in this piece, how long do the
batteries last and what does it cost to replace them?

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coredog64
GA engines require a teardown inspection on a pretty regular basis. Not only
that, but the liability tail for GA emphasizes the use of older designs.

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ams6110
Presumably electric motors would require the same, then, in an aviation
application?

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djrogers
The teardown and inspection of an electric motor is trivial compared to that
of an internal combustion engine. Generally speaking, you'd undo a few
fasteners, pop off a cover, and check/clean the rotor/windings. 15 minutes
tops - heck, you could do it before every flight and it'd still be cheaper
than paying for the 100-hour maintenance on a GA plane.

