Schempp-Hirth Ventus–3M Performance Preliminary Flight Manual page 99

SCHEMPP-HIRTH FLUGZEUGBAU GmbH, KIRCHHEIM/TECK
Ventus-3M „Performance"
4.5.5 Extending the power plant, starting the engine in flight
1. With the powerplant extended and engine off, the rate of descent is approx.
2.30 m/s (450 fpm) at a speed of 105 km/h (57 kt, 65 mph), resulting in
a glide ratio of only about 13 : 1 – contrary to the best L/D of around 50 : 1 in
clean configuration (power plant retracted).
Therefore the engine should only be restarted over terrain suitable for an off-
field landing and, if possible, n o t below 300 m (984 ft) AGL.
However, it is better to extend the power plant on the downwind leg to a
suitable landing field at 200 m (656 ft) AGL than eg. starting it at 500 m (1640
ft) AGL above a forest or similar.
Should a flight be planned over long distance without any acceptable landing
fields, the power plant should be extended at a height giving sufficient time
for all emergency procedures and, if necessary, for re-retracting the power
plant.
2. Starting the Engine in Flight:
(See also check-list on page 4.5.2.1)
o Power plant master switch ON
o OPEN fuel shut-off valve
o Set throttle to idle
o Set speed to 95 to 100 km/h (51-54 kt, 59-62 mph)
o Ignition ON
o Only in manual operation: EXTEND powerplant using manual control
switch
o When power plant is fully extended (green signal):
o Depress starter button
The loss of height from extending the propeller to the moment the engine is
running is about 40 to 50 m (131-164 ft) and needs 35 to 45 seconds.
March 2019
Revision –
FLIGHT MANUAL
CS 22
4.5.5.1