On 4 nov., 18:10, Herbert kilian wrote:
Here is a video of a composite launch of a LAK 17 by means of auto-tow
followed by using the electric sustainer that is installed in front of
the pilot. *Looks like a promising new launch method provided the car
gets the glider high enough for a dealing with any launch
interruptions.http://blog.cafefoundation.org/?p=4759
It says nothing about the time it takes to get to around 1,500' AGL,
the altitude I usually release from tow. *The remaining charge in the
Li-Po batteries may not be sufficient for a normal stustainer
operation (20-30 min) at the end of the day but you can always throw
in more batteries, I suppose.
Herb, J7

You can download igc file of this flight, where you can see climb rate
data.
At end of flight was another climb for about 1000m (17-20kW of power)

http://www.onlinecontest.org/olc-2.0...l?dsId=2137595

As there is adjustable throttle, pilot can fly horizontaly on low
power (4kW only due to very clean aerodinamic) for more than one hour
with fully charged batteries (4,2kWh of energy in 30kg of batteries).
Total climb available with 4,2kWh is about 1500m, at 400kg take-off
weight.
So with initial 450m (1,500' AGL) of climb to catch thermal, there is
still about 2/3 energy left. This is enough for another 65 km of
horizontal flight to get home!

Regards,

Luka