Do not operate deicer boots continuously.
Continuous operation tends to balloon
the ice over the boots. Allow at least 1/2
inch of ice to accumulate on the surface
boots and 1/8 to 1/4 inch of ice to accu-
mulate on the antenna boots, then acti-
vate the deicer boots to remove the ice.
Repeat this procedure as required.
Ice vanes. Ice vanes must be extended
when operating in visible moisture or when freedom
from visible moisture cannot be assured, at 5°C
OAT or less. Ice vanes are designed as an anti-ice
system, not a deice system. After the engine air inlet
screens are blocked, lowering the ice vanes will not
rectify the condition. Ice vanes should be retracted
at 15°C OAT and above to assure adequate engine
Stall speeds. Stalling airspeeds should
be expected to increase when ice has accumulated
on the aircraft causing distortion of the wing airfoil.
For the same reason, stall warning devices are not
accurate and should not be relied upon. Keep a com-
fortable margin of airspeed above the normal stall
airspeed. Maintain a minimum of 140 KIAS during
sustained icing conditions to prevent ice accumula-
tion on unprotected surfaces of the wing. In the
event of windshield icing, reduce airspeed to 226
KIAS or below.
Descent. Use normal procedures in Section
II. Brake icing should be considered if moisture was
encountered during previous ground operations or
inflight in icing conditions with gear extended.
Landing. Landing on an icy runway should
be attempted only when absolutely necessary and
should not be attempted unless the wind is within
10 degrees of runway heading. Application of brakes
without skidding the tires on ice is very difficult,
due to the sensitive brakes. In order not to impair
pilot visibility, reverse thrust should be used with
caution when landing on a runway covered with
snow or standing water. Use the procedures in Sec-
tion II for normal landing.
Engine Shutdown. Use normal procedures
in Section II.
Before Leaving the Aircraft. When the air-
craft is parked outside on ice or in a fluctuating
freeze-thaw temperature condition the following
procedures should be followed in addition to the
normal procedures in Section II. After wheel chocks
are in place, release the brakes to prevent freezing.
Fill fuel tanks to minimize condensation, remove
any accumulation of dirt and ice from the landing
gear shock struts, and install protective covers to
guard against possible collection of snow and ice.
DESERT OPERATION AND HOT WEATHER
Dust, sand, and high temperatures encountered
during desert operation can sharply reduce the oper-
ational life of the aircraft and its equipment. The
abrasive qualities of dust and sand upon turbine
blades and moving parts of the aircraft and the
destructive effect of heat upon the aircraft instru-
ments will necessitate hours of maintenance if basic
preventive measures are not followed. In flight, the
hazards of dust and sand will be difficult to escape,
since dust clouds over a desert may be found at alti-
tudes up to 10,000 feet. During hot weather opera-
tions, the principle difficulties encountered are high
turbine gas temperatures (TGT) during engine start-
ing, over-heating of brakes, and longer takeoff and
landing rolls due to the higher density altitudes. In
areas where high humidity is encountered, electrical
equipment (such as communication equipment and
instruments) will be subject to malfunction by corro-
sion, fungi and moisture absorption by nonmetallic
Preparation For Flight. Check the position
of the aircraft in relation to other aircraft. Propeller
sand blast can damage closely parked aircraft. Check
that the landing gear shock struts are free of dust
and sand. Check instrument panel and general inte-
rior for dust and sand accumulation. Open main
entrance door and cockpit vent storm windows to
ventilate the aircraft.
N1 speeds of 70% or higher may be
required to keep oil temperature within
Engine Starting. Use normal procedures in
Section II. Engine starting under conditions of high
ambient temperatures may produce a higher than
normal TGT during the start. The TGT should be
closely monitored when the condition lever is
moved to the LO IDLE position. If overtemperature
tendencies are encountered, the condition lever
should be moved to the IDLE CUTOFF position
periodically during acceleration of gas generator
RPM (N1). Be prepared to abort the start before
temperature limitations are exceeded.
c. Warm-Up Ground Tests. Use normal proce-
dures in Section II. To minimize the possibility of
damage to the engines during dusty/sandy condi-