Hacker News Reader

Comment by marvin | Hacker News Reader

I fly gliders. Absolutely can't wait until my local club finally decides to get an electric single-seat self-launching glider, preferably with enough endurance to do some additional tens of kilometers after the launch, in order to avoid landing out if the weather dies out. It's a gamechanger with regards to both costs and convenience. No towplane, towplane pilot, no outlandings.

View on HN

I imagine solar would be a possibility for gliders.

They have high launch energy followed by zero propulsion very high-efficiency gliding afterwards.

Covering the large wing area could with solar cells and allow for range extension or possibly even continuous flight.

Solar panels are mostly structural, but the cells themselves are basically a thin foil.

How about a battery that can glide by itself? You attach a big battery for the launch and once you are up you disconnect and it glides back to the airfield. That should be possible today technically. Not sure how safety would work.

What you are thinking of is not very different than an aerotow from an electric airplane.

I was just thinking about something autonomous. Basically a battery with wings. That way you don't need a plane with pilot.

Well, we already have autonomous electric planes. I don't see why your idea shouldn't work. For the near term, remote control of the battery might be easier/more feasible.

Parachute not enough?

I don't think so. You cant steer a parachute well and you don't want some bypasser to get hit by a heavy battery on a parachute. The descent speed on a parachute is very high so it will hurt or more.

Parachutes can be steered.

you might like rctestflight's youtube channel

here he gets a battery powered drone with solar to gain altitude and charge the batteries during clear skies: https://www.youtube.com/watch?v=xS2iCj-HSqY

here he shows off a new feature in arduinopilot, autonomous thermaling: https://www.youtube.com/watch?v=NwAX3cPvMqw

also, check out the "Sunseeker Duo" https://www.solar-flight.com/sunseeker-duo/ https://www.youtube.com/watch?v=2zvwqJpyahs

its only a matter of time before someone combines them

Oh, electric self launch planes are both viable and available already. It's just a question of manufacturers making them with slightly higher battery capacity, which seems perfectly feasible based on a napkin calculation. Current self-launch electric gliders can climb to cruise altitude and still have >20km of endurance as a contingency for recovery.

If that number was 100km with high reliability, it would almost qualify as a new type of aircraft. You could do cross-country flights that you'd never attempt in an unpowered glider, e.g. above big stretches of high, mountainous terrain. The Norwegian Hardanger plateau comes to mind as an example. Un-landable terrain, 1 km above sea level with a small window for unpowered navigation, national park and absolutely beautiful.

I also started to fly gliders, and it would be lovely indeed to have electric self-launching glider, though unfortunately atm there are just too few of them, most popular are Arcus E and ASG 32 El, both are too new (cost a lot of money) and too rare. I wouldn't mind if our club get one, but it might be more economical to get a few other high performance gliders instead (like get two ASW 27 instead of one ASG 32 El) as it much easier to deal with them in a club context (doing 5+ launches per day, maintenance, etc).

Most likely a first viable step would be to get electrical tow plane first.

Self launching on batteries means carrying around a fair bit of dead battery weight for the entire flight. Electric sustainers (can't take off but can stay up) are pretty interesting because gliders take hardly any power to fly level. Example:

* http://front-electric-sustainer.com

All this electric vehicle technology works really well for electric glider winches. You can get a whole lot of peak power off of a battery so you don't need a huge electric power feed.

Are super capacitors lighter and a better choice for the self-launching use case?

I have no idea, hence asking and wanting to know :-)

Maybe. Nawa's ultra-capacitors sound good:

https://newatlas.com/nawa-nanotube-ultracapacitor-production...

I hope they get adopted by Formula E. A bank of ultra-capacitors in front of the main battery should make the cars lighter with stronger regenerative braking.

Reply on news.ycombinator.com