On 10/12/20 8:46 AM, kinsell wrote:
On 10/8/20 6:54 PM, 2G wrote:
On Thursday, October 8, 2020 at 1:14:30 PM UTC-7, Mana wrote:
You'll get at least 2m/s dry. But like PF says, better to take a tow
to 400m and use the FES straight and level until you find a thermal.
It's much more efficient in level flight than climbing.

On the Shark, based on a test flight I think that you will get less
than 2m/s as it is a heavier glider than Matthew's Diana 2 :-).

Â*From the FES manual:
5.3.4.1 Rate of climb
TheÂ* maximum rateÂ* of climbÂ* isÂ* availableÂ* onlyÂ* forÂ* aÂ* few
minutesÂ* withÂ* fullyÂ* charged battery packs. As battery voltage is
reduced, the maximum achievable climb rate is lower. The average rate
of climb depends mostly on the type of sailplane and its take-off
weight. Maximum attainable altitude gain that in standard atmosphere
conditions depends on the typeÂ* ofÂ* sailplane,Â* itsÂ* weightÂ* and
aerodynamicÂ* qualities.Â* To achieve the maximum altitudeÂ* gain, use
aboutÂ* 15kWÂ* ofÂ* power. DoÂ* notÂ* useÂ* fullÂ* powerÂ* asÂ* the
efficiencyÂ* ofÂ* the systemÂ* isÂ* lower. Usually, 80-85Â* km/h isÂ* best
for theÂ* climb with positive flapÂ* setting (the same setting as used
while thermaling). Here are rough numbers:
•1600 m (5200 ft) for UL sailplanes at 300kg take-off weight, i.e.
Silent 2 Electro
•1400Â* m (4500Â* ft)Â* forÂ* theÂ* 18mÂ* classÂ* sailplanesÂ* atÂ* 400kg
take-off weightÂ* (without water ballast), i.e.LAK17A FES
•1200Â* mÂ* (3900Â* ft) forÂ* theÂ* 18mÂ* classÂ* sailplanesÂ* atÂ* 450kg
take-off weightÂ* (without water ballast); LAK17B FES, Ventus 2cxa
FES, Discus 2c FES, HPH 304ES

Sounds like a very marginal self-launch system and is really just a
decent self-retrieve (turbo) setup.

Tom


These gliders are sustainers only.

Looks like the Silent 2 is rated for self-launch.