TM 55-1510-215-10
(2) Taxiing. Extreme care must be exercised
8-50. Ice and Rain.
when taxiing on ice or slippery runways. Excessive use
of either brakes or power may result in an uncontrollable
WARNING
skid.
(3) Takeoff. Extreme care must be exercised
Autoignition shall be used before
during takeoff from ice or slippery runways. Excessive
entering anticipated or actual icing
use of either brakes or power may result in an
conditions (10C or below in visible
uncontrollable skid.
moisture).
(4) Climb. Climb at 10 to 15 KIAS above
normal climb speeds when icing conditions exist.
WARNING
Reducing the angle of attack minimizes the
accumulation of ice on all surfaces.
Extend the engine ice vanes when
(5) Cruising flight. Prevention of ice formation
temperature is 5C or below before
is more effective and satisfactory than attempts to
entering visible moisture. If the ice
dislodge the ice after it has formed. If icing conditions
formation is allowed to progress to a
are encountered on the anti-icing systems prior to the
critical point, the loss of intake air
first sign of ice formation. Refer to chapter 2 for use of
may make it impossible for the
deicer boots. Flight in severe icing conditions should not
engine to run at normal power.
be attempted. If ice forms on the wing area aft of the
deicer boots, climb or descend to an altitude where
a. If flights into known icing conditions are made,
conditions are less severe. At any time visible moisture
all anti-icing and deicing systems of the aircraft should
is present, turn on the pitot and stall warning heat. Refer
be properly utilized in accordance with the procedures
to chapter 2 for additional information.
detailed in chapter 2. Rain presents no particular
problems other than restricted visibility.
NOTE
b. The aircraft is equipped with anti-icing or deicing
Do not operate deicer boots
systems to prevent the formation of ice on the pitot tube,
continuously. Continuous operation
stall warning, fuel vents, heater air intake, engine air
tends to balloon the ice over the
intake, and propeller blades. Deicer boots are provided
boots. Allow at least 1/2 inch of ice
to remove ice from the wing and tail leading edges, and
to accumulate on the boots, then
an electrothermal windshield anti-ice system is provided
activate the deicer boots to remove
to prevent ice from forming on the windshield.
the ice. Repeat this procedure as
Windshield defrosters are installed to alleviate conditions
required.
resulting from frost or light ice. Windshield wipers are
installed for rain at lower airspeeds. An engine ice vane
(6) Landing. Extreme care must be exercised
is provided for removal of ice and rain from the engine
when landing on ice or slippery runways. Excessive use
intake air. An autoignition system automatically provides
of either brakes or power may result in an uncontrollable
combustion re-ignition if flameout should occur due to
skid.
icing conditions, etc. If severe icing conditions are
encountered ascend or descend to altitudes where these
NOTE
conditions do not prevail. Operation of deice and anti-
ice equipment discussed here is described in chapter 2.
Ice accumulation on the aircraft will
result in higher stalling airspeeds
(1) Icing.
Icing occurs because of
due to the change in aerodynamic
supercooled water vapor such as fog, clouds, or rain.
characteristics and increased weight
The most severe formation will generally occur at
of the aircraft due to ice buildup.
approximately -5C.
Approach and landing airspeeds
must be increased accordingly.
8-28
