I will write here just a few attributes of the FES which I think are the most important:



-reliable start, full power available in 1s, switching off also very quick

-no smell in cockpit, no oil on fuselage

-small noise outside and inside of cockpit

-low vibrations

-good max climb rate about 2,5m/s at 22kW for LAK17A (depend on weigh of glider)

-very efficient system (only 4kW of power is neccesery for horizontal flight) which gives about 100km of range

-big advantage is that 12V power is available from main baterie pack, (DC/DC converter) so you have finally enough power for Radio, Transponder, PDA, Vario etc, acctually for the whole flying season

-all 12V Pb batteries can be removed (this mean usually minus 5kg)

-only about 50kg of additional weigh - 5kg of Pb= 45kg

-no change of drag or CG position during engine run

-according Idaflieg test results, drag of propeller blades is really minimal (official results published in winter)

-very chaep charging of batteries, outside of glider

-virtually maintenance-free

-price in range of Solo sustainers



As there was a lot of votes today for JET (I think good article on link above helps) I think I need to lighten some more advantages of FES:

-Light gliders like Silent, AS13.5, Apis becomes with FES real selflaunchers with comparable or even better climb rates than if equiped with combustion retractable engines.

-Even when FES is installed on 18m glider, max climb rate is much better than it is achived with JET or Solo.

-As it is slower than JET you do not pass thermals too quickly, but you can do some turns to center (under power or even without, at normal thermaling speeds) and preserve energy. Actually is it suprising how much energy is even in weak thermals.

-You can use it in mountains, on the ridge to help you climb above the peaks. Even that you have motor you still feel it as soaring, so not bad feling...

-FES is possible to use even in horizontal flight trough (not too heavy) rain (ventlation is prefared to be closed) without fear to damage proppeller blades up to about 3500 RPM.

-Only at FES start is instant, so it can save you out of unladable valleys.

Regards,

Luka