Flight manual DG-800S
4.5.5
Flight at high altitude and at low temperatures
With temperatures below 0°C (32°F) for instance when wave flying or
flying in winter, it is possible that the control circuits could become
stiffer. Special care should be taken to ensure that there is no moisture on
any section of the control circuits to minimize the possibility of freeze up.
It could be advantageous to apply Vaseline along all the edges of the
airbrake cover plates to minimize the possibility of freezing closed.
Apply the controls in short periods.
It is not allowed to carry waterballast.
Caution:
1. At temperatures below -20°C (-4°F) there is the risk of cracking the
gelcoat.
2. Attention must be paid to the fact at higher altitudes the true airspeed is
greater than the indicated airspeed.
The max. speed VNE is reduced. See the following table:
Altitude in
meters 0-2000 3000
4000
5000
6000
VNE IAS km/h
270 256 243 230 218
Altitude in
ft.
0-6600 10000 13000 16000 20000
VNE IAS kts. 146 138 131 124 117
3. Dump the water ballast before you reach freezing altitude at +2°C
(36°F) or descend to lower altitudes.
4. Do not fly below 0° (32°F) when your glider is wet (e.g. after rain).
4.5.6
Flight in rain
With light rain the stall speed and the sink rate increases slightly and the
approach speed has to be increased.
4.5.7
Cloud flying
(not permitted with waterballast)
Take care to fly smoothly and coordinated. It is prohibited to use a spin as
a method for loosing altitude in the clouds. In case of emergency, pull out
the dive brakes fully before exceeding a speed of 200 km/h and dive at
200 km/h (108 kts.) to leave the cloud.
Issued: April 1997 4.14
