5-30B. ICING LIMITATIONS (SEVERE).
Severe icing may result from environmental
conditions outside of those for which the
airplane is certificated. Flight in freezing
freezing drizzle, or mixed icing
conditions (supercooled liquid water and ice
may result in a build-up on
protective surfaces exceeding the capability of
the ice protection system, or may result in ice
forming aft of these protected surfaces. This
ice may not shed using ice protection systems,
and may seriously degrade the performance
and controllability of the airplane.
a. During flight, severe icing conditions that exceed
those for which the airplane is certficated shall be
determined by the following visual cues. If one or more of
these visual cues exists. immediately request priority
handling from air traffic control to facilitate a route or an
altitude change to exit the icing conditions:
(1) Unusually extensive ice accreted on the
airframe in areas not normally observed to collect ice.
(2) Accumulation of ice on the upper (or lower. as
appropriate) surface of the wing aft of the protected area.
(3) Accumulation of ice on the propeller spinner
farther aft than normally observed.
b. Since the autopilot may mask tactile cues that
indicate adverse changes in handling characteristics. use of
the autopilot is prohibited when any of the visual cues
specified above exist.
or when unusual lateral trim
requirements or autopilot trim warnings are encountered
while the airplane is in icing conditions.
All icing detection lights must be operative prior
to flight into icing conditions at night. This
supersedes any relief provided by the master
minimum equipment list (MMEL) or equivalent.
5-31. CROSSWIND LIMITATION.
The maximum crosswind component is 25 knots at 90°.
The maximum angle of bank in a slip during landing is 8°.
Landing the aircraft in a crab will impose side loads on the
landing gear and should he recorded on the DA Form 2408
13-1. Refer to Chapter 8 for crosswind landing technique.
5-32. OXYGEN REQUIREMENTS.
A minimum ten minute supply of supplemental oxygen
shall be available during flight at or above an altitude of
25,000 feet based on the highest total aircraft oxygen flow
In addition to the supply required by the information
in the above paragraph. sufficient oxygen will be carried
for each flight. assuming a decompression will occur at the
altitude or point of flight that is most critical from the
standpoint of oxygen need. and that after decompression
the aircraft will descend. in accordance with the emergency
procedures. to a flight altitude that Will allow successful
termination of the flight. Following the decompression, the
cabin pressure altitude is considered to be the same as the
An oxygen system data/duration table may be found in
5-33. CABIN PRESSURE LIMITS.
Maximum cabin differential is 6.2 PSI.
5-34. CRACKED CABIN WINDOW / WIND-
If a crack occurs in an outer cabin window. the aircraft
is limited to an altitude of 25,000 feet, and maximum cabin
pressure differential is limited to 4.6 PSI. Maximum
operating time with a crack in an outer cabin window is 20
hours. If an external windshield crack is noted. no action is
required in flight. If an external crack occurs in either
cabin window or the windshield, refer to Chapter 9.