f. During Flight. Use normal procedures in Section
g. Descent. Use normal procedures in Section II.
h. Landing. Use normal procedures in Section II.
i. Engine Shutdown. Use normal procedures in
During hot weather, if fuel tanks are completely
filled. fuel expansion may cause overflow,
thereby creating a fire hazard.
j. Before Leaving Aircraft. Use normal procedures in
Section II. Take extreme care to prevent sand or dust from
entering the fuel and oil system during servicing. During
hot weather, release the brake immediately after installing
wheel chocks to prevent brake disc warpage.
8-50. TURBULENCE AND THUNDERSTORM
Due to the comparatively light wing loading,
control in severe turbulence and thunderstorms
is critical. Since turbulence imposes heavy
loads on the aircraft structure, make all
necessary changes in aircraft attitude with the
least amount of control pressures to avoid
excessive loads on the aircrafts structure.
Thunderstorms and areas of severe turbulence should be
avoided. If such areas are to be penetrated, it will be
necessary to counter rapid changes in attitude and accept
major indicated altitude variations. Penetration should be
of an altitude which provides adequate maneuvering
margins as a loss or gain of several thousand feet of
altitude may be expected. The recommended penetration
speed in severe turbulence is 150 KIAS. Constant pitch
attitude and constant power settings are vital to proper
flight technique. Establish recommended penetration speed
and proper attitude prior to entering turbulent air to
minimize most difficulties. False indications by the
pressure instruments due to barometric pressure variations
within the storm make them unreliable. Maintaining a pre-
established attitude will result in a fairly constant airspeed.
Turn cockpit and cabin lights on to minimize the blinding
effects of lighting. Do not use autopilot altitude hold.
Maintain constant power settings and pitch attitude
regardless of airspeed or altitude indications. Concentrate
on maintaining a level attitude by reference to the flight
director/attitude indicator. Maintain original heading.
Maker no turns unless absolutely necessary.
8-51. ICE AND RAIN (TYPICAL).
While in icing conditions, if there is an
unexplained 30% increase of torque needed
to maintain airspeed in level flight, a
cumulative total of two or more inches of ice
accumulation on the wing, an unexplained
decrease of 15 knots IAS, or an unexplained
deviation between pilots and copilots
airspeed indicators, the icing environment
should be exited as soon as practicable. Ice
accumulation on the pitot tube assemblies
could cause a complete loss of airspeed
a. Typical Ice. The following conditions indicate a
possible accumulation of ice on the pitot tube assemblies
and unprotected airplane surfaces.
If any of these
conditions are observed, the icing environment should be
exited as soon as practicable.
Total ice accumulation of two inches or more on
the wing surfaces. Determination of ice thickness can be
accomplished by summing the estimated ice thickness on
the wing prior to each pneumatic boot deice cycle (e.g. four
cycles of minimum recommended ½-inch accumulation.
(2) A 30 percent increase in torque per engine
required to maintain a desired airspeed in level flight (not
to exceed 85 percent torque) when operating at
recommended holding/loiter speed.
(3) A decrease in indicated airspeed of 15 knots
after entering the icing condition (not slower than 1.4
power off stall speed) if maintaining original power setting
in level flight. This can be determined by comparing pre-
icing condition entry speed to the indicated speed after a
surface and antenna deice cycle is completed.
(4) Any variations from normal indicated airspeed
between the pilots and copilots airspeed indicators.
Icing occurs because of supercooled water vapor such
as fog, clouds or rain. The most severe icing occurs on
aircraft surfaces in visible moisture or precipitation with a
true outside air temperature between -5°C and +l°C.
However, under some circumstances, dangerous icing
conditions may be encountered with temperatures below
-10°C. The surface of the aircraft must be at a temperature
of freezing or below for it to stick. If severe icing