On Saturday, April 11, 2020 at 9:04:39 AM UTC-7, wrote:
On Saturday, April 11, 2020 at 4:51:34 PM UTC+1, Martin Gregorie wrote:
On Sat, 11 Apr 2020 08:10:55 -0700, Muttley wrote:

There was a project in the UK for a UL Glider driven by a Motorised Main
Wheel and a Jet. Website still up at
http://www.proairsport.com/project-glow.php However do no think it ever
got of the Ground.

I think it was taxiied and have a feeling that was without wings fitted..

But UL? Its empty weight, 180 kg, is the same as the Diana 2.

--
Martin | martin at
Gregorie | gregorie dot org

I'd be interested to hear some reasons from the peanut armchair-aircraft-designer gallery as to why electric main wheels haven't "taken off" - seems like it would be a big win for both electric gliders in reduced launch energy, and solve the static thrust problem for jet self launchers?
The biggest problem I see is you'd need to have the main wheel a long way forwards, or a nose wheel to not pitch over on the belly?


Like to confirm a real world experience I had some years back while visiting El Tiro. I was there with my DG 800b took real interest in an Antares 20e that was tied down. I beleive the advertised climb from sea level in still air is 9000 ft. Well, sitting next to the glider was a hefty Honda gas generator. I asked the owner some question about his experience so far. First thing he said was he was disappointed. They found once the ground temperatures were above 100F they need to keep it in the shade before launch. If they left it ouside the batteries would over heat at around 1000AGL. Guess it😁 was designed for cooler climates like in Germany. Next I asked him how long it took to recharge the batteries from the generator.. He basically said all night long and consumed 10 gallons of gas. I doubt there are airports that would allow you to tap into their grid. El Tiro was using solar panels. On sites like Truckee where you can camp on the airport, you would become very unpopular in a hurry have that much noise. I have never seen an Antares fly from there, getting back into Truckee requires a climb to over 12,000 feet to safely get back in. The surrounding routes back in might have you starting the engine at 5-6k. Very marginal or impossible if you used the engine for self launch at the beginning of the day. In contrast the DG 800 will climb to well over 14k, personally in the winter I took off from sea level and climbed to 16k and it was still gaining 100-200 FPM. Recharging the gas tank takes less than 5 minutes for 5 gallons of fuel. When the battery's reach a much higher level of capacity and are able to be recharged in a different way, the electric glider will come of age, and i have no doubt they will. The backing to behind this push is driven by electric cars. Asking any one who owns a pure electric car and hear their stories on range anxiety. ONLY Tesla usiong super chargers do you see a charge time to drive time much less than one. My Volt is horrible! From a 110vac socket pulling 8 amps, it takes over 12 hours to get 40 minutes of driving time at 60 mph.