TM 1-1510-225-10 5-16 b.  Flight Load Factor Limits (12,500 Pounds). Any maneuver which results in a positive load factor of 3.17 G's or a negative load factor of 1.27 G's with wing flaps  up;  or  a  positive  load  factor  of  2.0  G's,  or  a negative load factor of 0 G's with flaps down. c.  Flight Load Factor Limits (14,000 Pounds). Any maneuver which results in a positive load factor of 3.10 G's or a negative load factor of 1.24 G's with wing flaps up; or a positive load factor of 2.0 G's, or 0 G's with flaps down. d.  Recommended     turbulent     air     penetration airspeed is 170 KIAS. 5-30.  BANK AND PITCH LIMITS. a.  Bank limits are 60° left or right. b.  Pitch   limits   are   30°   above   or   below   the horizon. Section VII.  ENVIRONMENTAL RESTRICTIONS 5-31.  ALTITUDE LIMITATIONS. The  maximum  altitude  that  the  aircraft  may  be operated at is 35,000 feet. 5-32.  TEMPERATURE LIMITS. a.  The  aircraft  shall  not  be  operated  when  the ambient temperatures are warmer than ISA +37 °C at sea level to 25,000 feet, or ISA +31 °C above 25,000 feet. b.  The    ice    vanes    shall    be    extended    for operations  in  ambient  temperatures  of  5  °C  or  below when flight free of visible moisture cannot be assured. c.  Minimum free air temperature for operation of deicing boots shall be –40 °C. 5-33.  FLIGHT   UNDER   INSTRUMENT   METEORO- LOGICAL CONDITIONS (IMC). This    aircraft    is    qualified    for    operation    in instrument meteorological conditions. 5-34.  ICING LIMITATIONS (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  2  or  more  inches  of ice accumulation on the wing, an unexplained  decrease  of  15  KIAS,  or  an unexplained  deviation  between  pilot's  and copilot's    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 indication. a.  The  following  conditions  indicate  a  possible accumulation  of ice on  the pitot tube  assemblies  and unprotected    aircraft    surfaces.        If    any    of    these conditions are observed, the icing environment should be exited as soon as practicable. (1)  If there has been a total ice accumulation of 2 inches or more on the wing surfaces, exit the icing environment as soon as practicable.  Determination of ice thickness on unprotected areas can be accomplished by summing the estimated ice thickness on the wing prior to each pneumatic boot deice cycle (i.e.,  four  cycles  of  minimum  recommended  ½-inch accumulation). (2)  If  there  is  a  30%  increase  in  torque  per engine required to maintain a desired airspeed in level flight,  not  to  exceed  85%  torque,  when  operating  at recommended holding speed, exit the icing environment as soon as practicable. (3)  If    there    is    a    decrease    in    indicated airspeed of 15 knots after entering the icing condition, not slower than 1.4 times the power off stall speed, if maintaining  original  power  setting  in  level  flight,  exit the  icing  environment  as  soon  as  practicable.    This can  be  determined  by  comparing  pre-icing  condition entry  speed  to  the  indicated  speed  after  a  surface deice cycle is completed. (4)  If  there  are  any  variations  from  normal IAS    between    the    pilot's    and    copilot's    airspeed indicators,   exit   the   icing   environment   as   soon   as practicable. WARNING