a. Preparation for Flight.
For ground operations conducive to ice
accumulation on landing gear structure,
use undiluted defrosting fluid on brakes
and tires to reduce the tendency of ice
accumulation during taxi, takeoff, and
Accumulations of snow, ice, or frost on aircraft
surfaces will adversely affect takeoff distance, climb
performance, and stall speed to a dangerous degree.
Such accumulations must be removed before flight. In
addition to the normal exterior checks, also check the
removal of ice, snow, or frost and inspect wing and
empennage surfaces to verify that these remain
sufficiently cleared. Move all control surfaces to
confirm full freedom of movement. Assure that tires
are not frozen to wheel chocks or to the ground. Use
ground heaters, anti-ice solution, or brake deice to free
frozen tires. When heat is applied to release tires, the
temperature should not exceed 71 °C (160 °F). Refer
to Chapter 2 for anti-icing, deicing, and defrosting
b. Engine Starting. When starting engines on
ramps covered with ice, propeller levers should be in
the FEATHER position to prevent the tires from
sliding. To prevent exceeding torque limits when
advancing CONDITION levers to HIGH IDLE during
the starting procedure, place the power lever in BETA
and the propeller lever in HIGH RPM before advancing
the condition lever to HIGH IDLE.
c. Warmup and Ground Test. The warmup
procedures and ground test are the same as those
outlined in Section II.
d. Taxiing. Whenever possible, taxiing in deep
snow, light-weight dry snow, or slush should be
avoided, particularly in colder FAT conditions. If it is
necessary to taxi through snow or slush, do not set the
parking brake when stopped. If possible, do not park
the aircraft in snow or slush deep enough to reach the
brake assemblies. Chocks or sand bags should be
used to prevent the aircraft from rolling while parked.
Before attempting to taxi, activate the brake deice
system, ensuring that the bleed air valves are OPEN
and that the condition levers are in HIGH IDLE. An
outside observer should visually check wheel rotation
to ensure brake assemblies have been deiced. The
condition levers may be returned to LOW IDLE as
soon as the brakes are free of ice.
e. Before Takeoff.
If the possibility of ice accumulation on the
horizontal stabilizer or elevator exists,
takeoff will not be attempted.
If icing conditions are expected, activate all anti-
ice systems before takeoff, allowing sufficient time for
the equipment to become effective.
Following takeoff from runways covered
with snow or slush, it is advisable to delay
gear retraction and to cycle the gear a few
times to dislodge ice accumulated from the
spray of slush and water.
Takeoff procedures for cold weather operations
are the same as for normal takeoff. Taking off with
temperature at or below freezing with water, slush, or
snow on the runway, can cause ice to accumulate on
the landing gear and can throw ice into the wheel well
areas. Such takeoffs shall be made with brake deice
on and with the ice vanes extended to preclude the
possibility of ice build-up on engine air inlets. Monitor
oil temperature to ensure operation within limits.
Before flight into icing conditions, the pilot's and
copilot's WSHLD ANTI-ICE switches should be set at
the NORMAL position.
g. During Flight.
(1) After take off from a runway covered with
snow or slush, it may be advisable to leave brake
deice ON to dislodge ice accumulated from the spray
of slush or water. Monitor the BRAKE DEICE
annunciator for automatic termination of system
operation and then turn the switch OFF. During flight,
trim tabs and controls should also be exercised
periodically to prevent freezing. Ensure that anti-icing
systems are activated before entering icing conditions.
Do not activate the surface deice system until ice has
accumulated 1/2 to an inch. The propeller deice
system operates effectively as an anti-ice system and
it may be operated continuously in flight. If propeller
imbalance due to ice does occur, it may be relieved by
increasing RPM briefly, then returning to desired
(2) Ice vanes must be extended when
operating in visible moisture or when freedom from
visible moisture cannot be assured, at +5 °C FAT or
less. Ice vanes are designed as an anti-ice system,
not a deice system. After the engine air inlet screens