TM 55-1510-219-10 CAUTION Do not pull out of the resulting dive too abruptly as this could cause    excessive    wing    loads and a possible secondary stall. 5. Pull out of dive by exerting a smooth, steady back pressure on the control wheel, avoiding an  accelerated  stall  and  excessive  aircraft stresses. 8-51.  DIVING. Maximum  diving  airspeed  (red  line)  is  245 KIAS   or   0.      47   Mach.      Flight   characteristics   are conventional throughout a dive maneuver; however, caution  should  be  used  if  rough  air  is  encountered after   maximum   allowable   dive   speed   has   been reached,  since  it  is  difficult  to  reduce  speed  in  dive configuration.    Dive  recovery  should  be  very  gentle to avoid excessive aircraft stresses. 8-52.  MANEUVERING FLIGHT. The  maximum  speed  (Va)  at  which  abrupt full  control  inputs  can  be  applied  without  exceeding the design load factor of the aircraft (Va 170 KIAS is shown  in  Chapter  5).    The  data  is  based  on  14,200 pounds.  There are no unusual characteristics under accelerated flight. Section V.  ADVERSE ENVIRONMENTAL CONDITIONS 8-53.  INTRODUCTION. The purpose of this part 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  part  is  primarily narrative,  only  those  checklists  that  cover  specific procedures  characteristic  of  weather  operations  are included.    The  checklist  in  Section  II  provides  for adverse environmental operations. 8-54.  COLD WEATHER OPERATIONS. Operational   difficulties   maybe   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. a. Preparation   For   Flight.      Accumulations   of snow, ice, or frost on aircraft surfaces will adversely affect  takeoff  distance,  climb  performance  and  stall speeds 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 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, antiice 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  must  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. Warm-Up    and    Ground    Test.        Warm-up procedures  and  ground  test  are  the  same  as  those outlined in Section II. d. Taxiing.  Whenever possible, taxiing in deep snow,   light   weight   dry   show   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  sandbags should  be  used  to  prevent  the  aircraft  from  rolling while parked.  Before attempting to taxi, activate the brake deice system, insuring 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 insure 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 If     icing     conditions     are expected,    activate    all    anti-ice    systems    before takeoff, allowing sufficient time for the equipment to become effective. f. Takeoff.        Takeoff    procedures    for    cold weather   operations   are   the   same   as   for   normal takeoff.    Taking  off  with  temperatures  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 8-23