TM 1-1510-218-10 8-28 a.    Preparation for Flight. 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. 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, also check the removal  of  ice,  snow,  or  frost  and  inspect  wing  and empennage    surfaces    to    verify    that    these    remain sufficiently   cleared.      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.    Warmup  and  Ground  Test.    The  warmup procedures  and  ground  test  are  the  same  as  those outlined in Section II. d.    Taxiing. Whenever possible, taxiing in deep snow,   light-weight   dry   snow,    or    slush    should    be avoided,  particularly  in  colder  FAT  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  sand  bags  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, takeoff will not be attempted. If icing conditions are expected, activate all anti- ice systems before takeoff, allowing sufficient time for the equipment to become effective. f. Takeoff. NOTE Following   takeoff   from   runways   covered with snow or slush, it is advisable to delay gear retraction and to cycle the gear a few times to dislodge ice accumulated from the spray of slush and water. Takeoff  procedures  for  cold  weather  operations are  the  same  as  for  normal  takeoff.    Taking  off  with temperature at or below freezing with water, slush,  or snow on the runway, can cause ice to accumulate on the landing gear and can throw ice into the wheel well areas.  Such takeoffs shall be made  with  brake deice on  and  with  the  ice  vanes  extended  to  preclude  the possibility of ice build-up on engine air inlets.  Monitor oil    temperature    to    ensure    operation    within    limits. Before   flight   into   icing   conditions,   the   pilot's   and copilot's WSHLD  ANTI-ICE switches should be set  at the NORMAL position. g.    During Flight. (1)   After take off from a runway covered with snow  or  slush,  it  may  be  advisable  to   leave   brake deice ON to  dislodge ice accumulated from the spray of    slush    or    water.        Monitor    the    BRAKE   DEICE annunciator    for    automatic    termination    of    system operation and then turn the switch OFF.  During flight, trim    tabs    and    controls    should    also    be    exercised periodically to prevent freezing.  Ensure that anti-icing systems are activated before entering icing conditions. Do not activate the surface deice system until ice has accumulated   1/2   to   an   inch.      The   propeller   deice system operates effectively as an anti-ice system and it  may  be  operated  continuously  in  flight.    If  propeller imbalance due to ice does occur, it may be relieved by increasing   RPM    briefly,   then   returning    to    desired setting. (2)  Ice    vanes    must    be    extended     when operating  in  visible  moisture  or  when  freedom  from visible  moisture  cannot  be  assured,  at  +5  °C  FAT  or less.    Ice  vanes  are  designed  as  an  anti-ice  system, not a deice system.  After the engine air inlet screens