TM 1-1510-218-10 8A-23 8A-54.  LEVEL FLIGHT CHARACTERISTICS. All     flight     characteristics     are     conventional throughout the level flight speed range. Section V.  ADVERSE ENVIRONMENTAL CONDITIONS 8A-55.  INTRODUCTION. This  section  is  to  inform  the  pilot  of  the  special precautions and procedures to be followed during the various weather conditions that may be encountered in flight.  This section is primarily narrative and only those checklists that cover specific procedures characteristic of  weather  operations  are  included.    The  Checklist  in Section II provides for normal environmental operations. The procedures defined here are supplementary procedures and are to be performed in addition to the normal procedures in Section II. 8A-56.  COLD WEATHER OPERATIONS. Operational    difficulties    may    be    encountered during  extremely  cold  weather,  unless  proper  steps are   taken   prior   to   or   immediately   after   flight.      All personnel  should  understand,  and  be  fully  aware  of, the necessary procedures and precautions involved. CAUTION For   ground   operations   conducive   to   ice accumulation   on   landing   gear   structure, use   undiluted   defrosting   fluid   on   brakes and   tires   to   reduce   the   tendency   of   ice accumulation    during    taxi,    takeoff,     and subsequent landing. a.     Preparation  for  Flight.    Accumulations  of snow,  ice,  or  frost  on  aircraft  surfaces  will  adversely affect  takeoff  distance,  climb  performance,  and  stall speed  to  a  dangerous  degree.    Such  accumulations must   be   removed   before   flight.      In   addition   to   the normal  exterior  checks,  following  the  removal  of  ice, snow, or frost, inspect wing and empennage surfaces to    verify    that    these    surfaces    remain    sufficiently cleared.  Also, move all control surfaces to confirm full freedom of movement.  Assure that tires are not frozen to   wheel   chocks   or   to   the   ground.      Use   ground heaters, anti-ice solution, or brake deice to free frozen tires.      When   heat   is   applied   to   release   tires,   the temperature should not exceed 71 °C (160 °F).  Refer to   Chapter   2   for   anti-icing,   deicing,   and   defrosting treatment. b.    Engine Starting.  When starting engines on ramps covered  with  ice,  propeller  levers  should  be  in the   FEATHER   position   to   prevent   the   tires   from sliding.      To   prevent   exceeding   torque   limits   when advancing  condition  levers  to  HIGH  IDLE  during  the starting procedure, place the power lever in BETA and the propeller lever in HIGH RPM before advancing the condition lever to HIGH IDLE. c.     Before  Taxi  and  Engine  Runup.    Before taxi   and   engine   runup   are   the   same   as   those   in Section II.  When the engine runup areas are slippery, the  crew  may  not  be  able  to  safely  accomplish  the runup procedures without causing the aircraft to begin sliding.      Under   those   conditions,   the   pilot   on   the controls  must  use  his  judgment  to  determine  which runup procedures will be accomplished. d.    Taxiing.  Whenever possible, taxiing in deep snow,    lightweight    dry    snow,    or    slush,    should    be avoided,  particularly  in  colder  OAT  conditions.    If  it  is necessary to taxi through snow or slush, do not set the parking brake when stopped.  If possible, do not park the aircraft in snow or slush deep enough to reach the brake  assemblies.    Chocks  or  sandbags  should  be used  to  prevent  the  aircraft  from  rolling  while  parked. Before   attempting   to   taxi,   activate   the   brake   deice system,  ensuring  that  the  bleed  air  valves  are  open and  that  the  condition  levers  are  in  HIGH  IDLE.    An outside  observer  should  visually  check  wheel  rotation to  ensure  brake  assemblies  have  been  deiced.    The condition  levers  may  be  returned  to  LOW  IDLE  as soon as the brakes are free of ice. e.     Before Takeoff. CAUTION If the possibility of ice accumulation on the horizontal  stabilizer  or  elevator  exists,  do not attempt takeoff. If icing conditions are expected, activate all anti- ice systems before takeoff, allowing sufficient time for the equipment to become effective.