Flying Over Highland Areas - Kazan Helicopters Mi-17-1V Flight Manual

MI1·17·1B. Flight manual
(8) The anti-icing system Is switched on and off by the Flight Engineer on the
Captain's order.
The procedures of switching the anti-icing system on and off,
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monitoring its operation are indicated in para. 7.1.
(9) At an ambient temperature of +5°C or above select the helicopter anti ic-
ing system to the automatic mode.
If icing takes place, switch off the main and tail rotors heaters after taxiing
to the parking area before switching off the AC generators, and the en-
gines anti-icing system before shutting them down.
Caution: With the main and tail rotors heaters operating, the range of
omnirange station call signs reception is reduced. To listen to
the omnirange station call signs switch off the main and tail ro-
tors heaters for this purpose set the respective circuit breakers
to "off"
(SbIKll)
for not more than 30 seconds. This done, the en-
gines air intakes anti-icing should operate in manual control
mode.
4.22. Flying over highland areas
(1) Reliable start of the engines at elevated fields from the airborne and
ground electrical power sources is ensured up to an elevation of 4000 m.
Land on fields elevated above 4000 m above sea level without shutting
down the engines.
(2) Only the pilots gained special skill in execution of takeoff from and land-
ings on elevated fields of limited dimensions are authorized to perform
flights over highland areas including landings.
(3) Flying over highland areas requires from the crew thorough study of the
weather conditions in the area of flights before executing a mission and
systematic monitoring of weather variations in flight.
Special care should be exercised in determination of the wind speed and
direction, as well as presence of clouds and their development.
(4) Due to limited number of fields suitable for landing in mountains it is ad-
visable to find them out and investigate in advance. During investigation
of unknown fields the helicopter weight should be within the limits ensur-
ing its hovering out of ground effect.
(5) Flying in summer over mountains with steep slopes, sharp ridges, sharp
protrusions of rocks appear to be most complex since non-uniform heat-
ing of the mountain slopes causes heavy up - and downdrafts, the first on
the sunny side and the second on the shadow side.
These drafts should be accounted for takeoff and landing on elevated
fields, as well as in flying at minimum altitudes.
(6) Flying in near proximity of mountain ridges in wind or in presence of verti-
cal clouds becomes even more complicated due to intensive bumpiness
and somewhat deteriorated controllability, particularly in flights with ex-
ternal loads.
(7) When flying over highland areas it is not recommended to come close to
the mountain slopes and heavy cumulus clouds which develop in day
time above the mountains.
Cross mountain ridges with a clearance not less than 600 m above ter-
rain. If it proves impossible to cross a ridge with such a clearance, cross it
at a sharp angle to the ridge to provide a possibility to rapidly turn aside
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