electric Cessna 172

[fly_tornado]

now if only they can deliver on those specs, I suspect it wont have 2 hours range.

 

 

 

[Guest Jake.f]

Doubt that battery technology right now is efficient and reliable enough to achieve that. However one of these days using avgas is going to become unpractical and there needs to be some alternative...

 

 

[Ultralights]

i think they should be following the technology in the new GM Volt, small torquey diesel engine turning a generator and running a brushless powerful electric engine.

 

 

[Vorticity]

http://www.sonexaircraft.com/research/e-flight/ the numbers don't seem very practical at this stage but you have to start somewhere.

[fly_tornado]

172 makes more sense than the sonex, they are converting a 4 seat cessna to a 2 seat electric

 

 

[turboplanner]

The video above is from 2009, and included what now turns out to be a little wishful thinking based on the great ideas of the day. I did quite a search because they scored publicity all round the world and across a lot of industries by telling the story that they were getting closes and closer to a first/second quarter flight, and that doesn't seem to have happened.

 

My moon rocket is also in the planning stage.

 

It's still an interesting concept though:

 

The thin film solar process has become a reality. You can print the dots on adhesive backed material, so today you could cover the cowl and fuse across the top and part way down the sides as well as the full wing shape, horizontal stabilisers, elevators etc. The thin film process currently is down about 30% on efficiency compared to solid silicon but is much less expensive. I'm looking at it to cover Tautliner roofs for trucks, and it owuld give a substantial extension of range. As they mentioned this also allow free recharging when parked or on a country stop.

 

The 10% - 14% parasite drag reduction through not needing the wide cowl with openings for the engine cylingers is very significant.

 

Energy re-generation through the prop on descent was an other great idea of the time which we looked at in the transport industry, but it had disadvantages of more complexity and driveline resistance for a marginal gain. Someone will come up with the solution one day.

 

The idea of running a JetA1 powered turbine APU (Auxiliary Power Unit) would transform it into a hybrid to extend range get you down slower, but also suffers from the complexity of generation, space, cost etc.

 

OF course LiPo batteries have taken off since the concept was released, and somone may still solve the thermal runaway problem, or the batteries I posted on a couple of months back may be successful.

 

20,000 to 30,000 hours engine life sounds good to me along with saying goodbye to the ever increasing cost of fossil fuels.

 

I also liked the idea of the kit being set up to allow the conversion of an existing C172.

 

 

[fly_tornado]

look how cheap lipos are getting

 

http://www.hobbyking.com/hobbyking/store/__18562__Turnigy_5000mAh_1S_40C_Lipoly_Single_Cell.html

 

$10k gets you 1000 x 5000mah batteries or a 130Kg battery back!

 

 

[old man emu]

The 20-30,ooo Hrs TBO on the motor is equivalent to ten to fifteen engine lifetimes. At an approximate overhaul cost of $30,000 in today's money, that TBO life would equate to sometwhere near a half million dollar saving.

 

Regarding battery development. I'd never say, "Never" I can remember using NiCad batteries in Radio controlled planes in the 80's. They had a short working time span and a long regeneration time. Now we have LiPo batteries with long working time and short regeneration time. One can only beleive that in 10 years' time battery storage capacity will be much greater and regeneration time will be much shorter.

 

As for capturing vortex energy. or any other energy coming from the airplane's movement. that's been done for years. There have been wind powered generators on aircraft since the need for electrical power became necessary.

 

Is it so bad that the developers are saying that the electric C172 will only carry two? In all honesty, how often do you see a C172 loaded up until the door skins bulge? What about an electric Skycatcher? If a rapid charge system can be developed, this type of plane will be a boon to flying schools.

 

OME

 

 

[turboplanner]

We're waiting to hear Ozzie's report when he gets back from Oshkosh.

 

 

[turboplanner]

Brushless motors are used in hydroponic systems, run 24/7

 

 

[eightyknots]

There are -as at today's date- still no flights of this electric Cessna 172 that I can find on the internet. I wonder if the project has stalled in some way?

 

 

[turboplanner]

Techology which looks simple can often drive you berserk trying to find a solution.

 

In my early days as a draftsman my job was to design electric fork lift trucks. The base engine was a six cylinder Holden, so we had to put a big torque motor in.

 

The acceleration control was simply a series of micro switches which connected more and more batteries as the foot went down. As you would expect, unless the operator changed the batteries around continually, some of them had very short lives. Maybe that design has been changed now, but it had lasted for 20 years last time I looked.

 

 

[eightyknots]

Techology which looks simple can often drive you berserk trying to find a solution.In my early days as a draftsman my job was to design electric fork lift trucks. The base engine was a six cylinder Holden, so we had to put a big torque motor in.

The acceleration control was simply a series of micro switches which connected more and more batteries as the foot went down. As you would expect, unless the operator changed the batteries around continually, some of them had very short lives. Maybe that design has been changed now, but it had lasted for 20 years last time I looked.

That is really interesting, turboplanner: the method you describe sounds like a very "agricultural" solution so I am surprised that it lasted that long before someone came up with a more "elegant" engineering solution.

 

Hopefully the Bye Engineering Cessna won't have a throttle consisting of a series of microswitches turning on more batteries. You would have a situation that you would land with some batteries still being partly charged while others (used in the climb) being just about flat.

 

 

[Guest ozzie]

http://www.airventure.org/electric/symposium.html

 

If you are heading over then this is one of two events available for free.

 

The lazair may not be going or if it does fly in it will not perform in the electric flying display due to the (too) late notification by the EAA for the need of liability insurance.

 

There may be a slim chance of actually going to Dale's home for some one on one, '101 lazair electrics' the week after Airventure. That could mean actually flying it. FAR103 means no problems.

 

Now as for the C172. It is just an airframe. It's cheap, available and chances are they already had it. If you can nut out the power package, mount the whole thing so it stays within the original CG limits then you will find just about everything you need off the shelf. Straight electric, hybrid. It is already out there, off the shelf or in a wrecking yard.

 

Don't be surprised if projects start then suddenly disappear in this economy. I don't think any of the commercial projects being worked on over the last 12/18 months have flown for long periods yet. BUT it is all poised to happen and i think that when will have a lot to do on what the industry accepts as a standard. The big players in all this will have the next 25 years of the market set out before even producing the first series.

 

What i will be paying close attention to at these symposiums will be the regulation side of it all. The FAA and Congress are doing their bit to get all this happening with a minimum of fuss.

 

Ratings? What knowledge will pilots and engineers need to have before flying or working on electric aircraft? With the way the FAA are working along side developers etc that when it all does come into play the changes and additions to the regs will be pretty seamless. The real interesting thing will be to see how messed up it all becomes as it travels across to this side of the Pacific. Not a joke. CASA have this history. I have this recurring nightmare about how complicated the act of plugging in an onboard charger to a suitable onfield power outlet becomes when CASA gets to write it up. Starts with . 'The electrical power supplied must be generated in a 'approved' facility'. CASA won't be able to help themselves they will find a way to screw it all up.

 

Follow the Airventure website when the convention is on some parts of the symposiums may be streamed LIVE.

 

Ozzie

 

 

[Guest pookemon]

look how cheap lipos are gettinghttp://www.hobbyking.com/hobbyking/store/__18562__Turnigy_5000mAh_1S_40C_Lipoly_Single_Cell.html

$10k gets you 1000 x 5000mah batteries or a 130Kg battery back!

Yeah - good luck getting that from HobbyKing - I ordered 6 batteries from them, received two then had an 8 month battle to try and get the other 4 - which ended in me giving up - so I don't order from them any more.

LIPO and brushless seems to be the obvious way to go (though there are better battery technologies on the horizon) - but you'd have to be able to keep the battery pack(s) etc. cool - you don't want your mass of lipos erupting into flame when you're in the air (or on the ground for that matter). The next big challenge would be a speed controller that could handle the current required. Some models will pull over 200Amps without too much effort - and you just about need to use Train track to hold the current.