Electric powered BH ultralight

[svyolo]

Thinking about it a bit more, I think the LSA might might make a more marketable electric plane than an ultralight. LSA builders are typically older (and better off financially), and adding 20k to a 70K airplane is easier to swallow than adding 15k to a 25k airplane.

[Chewie]

Bob makes no claim that his ultralight will be practical. Ultralights are rarely so. That's the beauty of them. Once you go ultralight, you can relax a lot of the "practical" requirements you might otherwise have with standard or utility category. A one-hour flight is considered a long flight in any ultralight, with 15-30 minutes being typical. I think the biggest issue will be system cost.

[Flytaildragger]

An affordable Plans built or kit ultralight is just what is needed right now with only one real competitor (Legal Eagle). Gas powered and folding wings would be the #1 leader in my humble opinion.

[zkelley2]

Ultralight isn't the answer with electric, it's glider or LSA-glider if you want. Electric motor glider to be specific. The FARs treat gliders with about the same I don't care about anything you do in them as an ultralight, except without the weight limit.
A great example of taking advantage of these rules is the Pipistrel Virus. Anyone looking at it would say it's just a small plane, but it's in the glider category. They have the 912 and electric options for powerplants. Ridiculous speed and range(147kts and 7.5hrs) without the arbitrary LSA limits, especially the really dumb fixed pitch prop limit.

I see Jim above mentioned Brian and Carol Carpenter already and I'd highly recommend getting in touch with them. I've taken their 15 day course.

https://electricmotorglider.com/

[geraldmorrissey]

Charles Lingbergh to the skeptics, "It has ro be tried now".
Gerry
Pateol #30

[geraldmorrissey]

Fat fingers, Lindbergh.
Gerry

[way_up_north]

The Sonex people did a flight if i remember correctly.... ...battery motor combo back in 2010...lots on info online if there is an interest....as others have said battery technology is the limiting factor..

other interesting videos...

this plane claims a 3 hour flight time

[bcbearhawkLSA]

Just prior to reading this post, ..I've just held up the master rib of my Bearhawk LSA against the Merlin GT wing that I'm currently re-doing in the shop here, thinking how simple, light and yet strong the foam, aluminum caps and solid D-cell leading edge actually are (and single strut - which Bob likes). To be honest I was wondering if one should re-do the Merlin wings with the Bearhawk LSA airfoil. And I'm still tempted. Why, well as comparison, my BushCaddy R80 wings which are similar to the LSA wing are substantially heavier, most likely stronger but at the 1232 MTOW here in Canada maybe a little overbuilt (compared to the 601, 701, Savannah, Kitfox, Beaver's, Chinook's etc).
Don't think I ever felt less safe in a Merlin GT as I do in other advanced UL's or LSA's. As for the history of this foam type of wing construction, it goes right back to the Grandmother of all UL's, the venerable Lazair. And in good Lazair tradition of leading innovation they went electric, ..and electric on floats. https://www.youtube.com/watch?v=YINO0aoSAGg
Personally I'd rather see a slightly lighter version of the Bearhawk LSA as a UL vs the rather winged garden chair set up of the Lazair. I think it's time to soul search and start looking closely where we came came from in the UL field and what is available to us in state of the art materials, machining and power plants. To just re-invent 1930's designs will give you exactly that, a re-invented 1930's design over and over again.
Further more, I totally agree that one needs to take a serious look to Europe and China. Ooh ..and maybe Vancouver, BC where Harbour Air decided to go electric on their DeHavilland Fleet of Beavers and Otters. I'm certain and without a doubt, that the first company which can offer an electric plug & play drive system into a Rotax 912 engine mount will come out the clear winner. Electric flight is coming and the winners will once again be those that weren't afraid to drop the typewriter for a laptop.

And NO, I wouldn't entertain 1/2VW's, Rotax's, Polini's, Simonini's, ..what's the point, 1930's all over again? Think my calendar shows 2019. Keep dreaming, keep building, keep innovating!

[nborer]

Mark, I’m a bit late to this party, but I’m happy to chat with Bob about electric aircraft. PM if you think he’d be interested. I’ll also probably be working at Oshkosh if you think that may be a good time to discuss.

In terms of references, skim through some of the full-length papers and presentations here. This list does not show the latest publications, but I think you may find the Preliminary Design Review (Nov 2015) and especially the Critical Design Review (Nov 2016) helpful regarding the components and architectures for electric aircraft.

https://www.nasa.gov/aeroresearch/X-...cal/index.html

[Mark Goldberg]

Bob told me he was concentrating on getting the structure built - and then he would focus on the electric motor and controller. He thought things are changing so fast that it made the most sense to wait until the last for that. He does have a target motor weight and power required in mind.

Mr. BC Bearhawk LSA - we think the existing BH LSA will be a good choice for the Canadian Advanced UltraLight category - AUL. Even with the restriction in gross weight to 1232 lbs, it seems to have many advantages over the planes in that category in Canada right now. Mike Silvernagle (Bearhawk Canada) will be pursuing this path. Mark

[bcbearhawkLSA]

Mark, now that’s something to look forward to, AULA LSA, that is.

[spinningwrench]

I could see this as my next project. I spent most my working career in electronics and motor controls. There is a lot of activity in this area, one possible related connection are the guys doing electric racing go-carts.

[bcbearhawkLSA]

Here is an “electrifying link” for various parts.

https://www.mgm-compro.com/other-products/electric-motors/

[schu]

I honestly don't think this is going to work based on how much electric cars weigh and the cost. Here are a few things to factor:

1. The electric motor and speed controller are fairly heavy. You could probably get something in the 26hp/20kw range down to 75lbs, but not less than that. Here are examples: https://www.goldenmotor.com/frame-bldcmotor.htm or https://www.alibaba.com/product-deta...725a7960V9b90C or even (4) of these turning a common gear https://www.monsterscooterparts.com/...or-golden.html

2. In order to provide a 15kwatt (20hp) power output, given 90% efficiency, for 45 minutes, that would take a 48volt 234amp/hour battery. And for lithium batteries, you don't want to discharge more than 90% because it hurts the battery so much, so you really need a 257amp/hr battery. So you would need a 12336 watt/hour battery (257amp/hr x 48 volts).

3. Looking at a battery tech, right now the most energy dense batteries are Li-Polymer (read dangerous) or Li-ion (which is what the cars use, and only mostly dangerous). Li-ion cylindrical cells are around 150watts per Kg. (https://www.epectec.com/batteries/cell-comparison.html) So if we look for 12336 watts like above, this battery will weigh around 82kg, or 180lbs.

4. The battery and motor above are getting into 255lbs, and we haven't covered wiring, speed control, cooling (batteries and motor and speed controller)....

5. If we look at a fuel engine, perhaps the Polini Thor 250 Engine used in the Just Solo 103 ultralight, it weighs less than 50lbs with radiator, and starter, and produces 36hp. Add another 36lbs in fuel and you get less than 90lbs of engine/fuel and it can easily go for an hour and a half. Even the 1/2 Vdub is lighter than an electric power system, by a lot.

Call ma a pessimist, but I've done a lot of electric conversions for model scale aircraft (and I fly electric Helicopters) and the only way that electric is lighter than a fuel airplane is if you cut the run time down to 3-4 minutes. That said, if you are willing to live with the fuel payload trade-off, the electrics are very powerful and smooth.

schu

[spinningwrench]

That is actually my next project after the Patrol.. My career was in motors and control systems. I would think some of the all electric motorcycles would make good donor machines.