At 05:55 28 November 2016, son_of_flubber wrote:
>On Saturday, November 26, 2016 at 12:06:03 AM UTC-5, son_of_flubber
wrote:
>> Will GP electric drive gliders be certified to aerotow with the boom
>depl=
>oyed and the motor turned off? (Boom extended in case of PT3. Aerotow
to
>=
>save the battery charge for later in the flight.)
>
>Sorry that I cannot point to specifics, but I read somewhere that towing
>gl=
>iders with the boom extended and the motor running is sometimes done in
>Eur=
>ope in order to compensate for low powered tugs. This would be a good
>reaso=
>n for GP to certify for extending the boom during aerotow.
>
>As Andrzej noted, the prop on the GP has less drag when it is folded.
And
>=
>the motor looks sleek. And since it is electric, I'd guess that you
could
>=
>dial in just enough thrust to negate the drag of the extended boom (and
>sav=
>e the batteries for later).
>
>Being able to use FES to recover from PT3 is very appealing if you launch
>f=
>rom a short runway with limited low altitude PT3 options. A plus if GP
>offe=
>red comparable functionality.
>
>That said, as battery costs comes down and power density increases,
>aerotow=
>ing a self-launch capable electric glider will at some point stop making
>se=
>nse. Maybe that will happen sooner rather than later.
>
>Do self launch gliders have the climb rate and stability to deal with
>stron=
>g sink on launch and the rotor associated with wave, or are they marginal
>o=
>n turbulent days? =20
>
The first flights of the GP Velo indicate an average climb under power of
4m/s, this is very encouraging and also very safe. See
https://www.facebook.com/gpgliders/