TM 1-1510-225-10 8-25 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. f.     Takeoff. NOTE Following   takeoff   from   runways   covered with  snow  or  slush,  consideration  should be   given   to   operating   the   landing   gear through   several   complete   cycles   (within limits)  to  dislodge  ice  accumulated  from the spray of slush and water and to prevent gear freezing in the retracted position. 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 NORMAL position. g.    During Flight. (1)   After takeoff 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 BRAKE DEICE ON 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 to 1/2 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  OAT  or less.    Ice  vanes  are  designed  as  an  anti-ice  system, not a deice system.  After the engine air inlet screens are blocked, extending the ice vanes will not rectify the condition.    Ice  vanes  should  be  retracted  at  +15  °C OAT and above to assure adequate engine oil cooling. (3)   Stalling airspeeds should  be  expected  to increase  when  ice  has  accumulated  on  the  aircraft causing  distortion  of  the  wing  airfoil.    For  the  same reason,  stall  warning  devices  are  not  accurate  and should not be relied upon.  Keep a comfortable margin of airspeed above the normal stall airspeed.  Maintain a   minimum   of   140   knots   during   sustained   icing conditions to prevent ice accumulation on unprotected surfaces of the wing.  In the event of windshield icing, reduce airspeed to 226 knots or below. h.    Descent.  Use normal procedures in Section II.  Brake deicing should be considered if moisture was encountered  during  previous  ground  operations  or  in flight, in icing conditions with gear extended. i.     Landing. Landing on an icy runway should be   attempted   only   when   absolutely   necessary   and should not be attempted unless the wind is within 10 of   runway   heading.      Application   of   brakes   without skidding  the  tires  on  ice  is  difficult.    In  order  not  to impair pilot visibility, reverse thrust should be used with caution when landing on a runway covered with snow or  standing  water.    Use  procedures  in  Section  II  for normal landing. j.     Engine Shutdown. Use normal procedures in Section II. k.    Before Leaving Aircraft. When the aircraft is parked outside on ice or in a fluctuating freeze-thaw temperature condition, the following procedures should be  followed  in  addition  to  the  normal  procedures  in Section II.  After wheel chocks are in place, release the brakes to prevent freezing.  Fill fuel tanks to minimize condensation, remove any accumulation of dirt and ice from    the    landing    gear    shock    struts,    and    install protective  covers  to  guard  against  possible  collection of snow and ice. 8-57.  DESERT  OPERATION  AND  HOT  WEATHER OPERATION. Dust, sand, and high  temperatures  encountered during    desert    operation    can    sharply    reduce    the operational life of the aircraft and its equipment.  The abrasive   qualities   of   dust   and   sand   upon   turbine blades and other moving parts of the aircraft  and  the destructive effect of heat upon the aircraft instruments will    necessitate    hours    of    maintenance    if    basic preventive  measures  are  not  followed.    In  flight,  the hazards  of  dust  and  sand  will  be  difficult  to  escape, since   dust   clouds   over   a   desert   may   be   found   at