Test Flight LAK-17A FES
Postojna Airfield 6.9.2013

Big thanks (!) to Luka Žnidaršič for organizing the test flight and especially his father who let me try his personal plane: a LAK-17A FES (Front Electric Sustainer), the FES being developed and built by Luka.

Below my impressions - the test was a bit hampered by the excellent soaring conditions: thermals about everywhere. Sometimes no sink even between clouds, which made it difficult to gauge glider and FES performance.

LAK (18m configuration):
the glider handles very lightly (2 fingers), including the flaps - very little effort to adjust.
I did not like the trim setting mechanism so much - adjustment needs too much force for my taste. Handling was instant and easy. Big change in angle of attack at higher speeds; needs also some additional trim for high speed (not just flap change). Cockpit view is great, and lots of room (especially for the legs - and I can pull my knees up towards the chest, which I like for long flights). Needs landing speed 100km/h on flap+2 with 70kg pilot (and FES weight). Landing was easy with quite effective brakes.

FES:
handling is phantastic: power switch on, turn the poti and get the power you like. On/off in an instant, anytime. You could actually use it for landing it like a SEP (more power last moment when coming too short), even so that would not be an appropriate technique for gliders.
It was more noisy than I thought, with a screeching noise when the engine is running (depends on the RPMs of course). I think it should only be used in straight flight.

Also some pictures of a Silent with FES (it also shows the new batteries with integrated balancer and more sophisticated connectors; the LAK has an older version installed).

If you think about buying an electric glider, I highly recommend to talk to Luka!
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