TM 55-1510-219-10 PROACH and DOWN, the APPROACH position acts as an   off   position.      To   return   the   flaps   to   any   position between  full  DOWN  and  APPROACH,  place  the  flap switch to UP and when desired flap position is obtained, return   the   switch   to   the   APPROACH   detent.      In   the event that any two adjacent flap sections extend 3 to 5 degrees     out     of     phase     with     the     other,     a     safety mechanism is provided to discontinue power to the flap motor. b. Wing    Flap    Position    Indicator.        Flap position  in  percent  of  travel  from  "O"  percent  (UP)  to 100    percent    (DOWN),    is    shown    on    an    indicator, placarded  FLAPS,  located  on  the  subpanel  (fig.    2-6). The approach and full down or extended flap position is 14   and   34   degrees,   respectively.      The   flap   position indicator   is   protected   by   a   5-ampere   circuit   breaker, placarded   FLAP   CONTR,   located   on   the   overhead circuit breaker panel (fig.  2-26). Section VI.  PROPELLERS 2-43.  DESCRIPTION. A  three  blade  aluminum  propeller  is  installed  on each   engine.      The   propeller   is   of   the   full   feathering, constant speed, counter-weighted, reversible type, controlled  by  engine  oil  pressure  through  single  action, engine driven propeller governors.  The propeller is flange mounted to the engine shaft.  Centrifugal counterweights, assisted  by  a  feathering  spring,  move  the  blades  toward the  low  RPM  (high  pitch)  position  and  into  the  feathered position.    Governor  boosted  engine  oil  pressure  moves the  propeller  to  the  high  RPM  (low  pitch)  hydraulic  stop and  reverse  position.    The  propellers  have  no  low  RPM (high  pitch)  stops;  this  allows  the  blades  to  feather  after engine    shutdown.        Low    pitch    propeller    position    is determined by the low pitch stop which is a mechanically actuated, hydraulic stop.  Beta and reverse blade angles are controlled by the power levers in the beta and reverse range. 2-44.  FEATHERING PROVISIONS. Both  manual  and  automatic  propeller  feathering systems are provided.  Manual feathering is accomplished by  pulling  the  corresponding  propeller  lever  aft  past  a friction detent.  To unfeather, the propeller lever is pushed forward     into     the     governing     range.          An     automatic feathering   system,   will   sense   loss   of   torque   and   will feather  an  unpowered  propeller.    Feathering  springs  will feather the propeller when it is not turning. a. Automatic  Feathering.    The  automatic  feathering system   provides   a   means   of   immediately   dumping   oil from  the  propeller  servo  to  enable  the  feathering  spring and counterweights to start feathering action of the blades in the event of an engine failure.  Although the system is armed    by    a    switch    on    the    overhead    control    panel, placarded AUTOFEATHER ARM OFF TEST, the completion of the arming phase occurs when both power levers  are  advanced  above  90%  Ni  at  which  time  both indicator  lightson  the  caution/advisory  annunciator  panel indicate a fully armed system.  The annunciator lights are green and are placarded #1 AUTOFEATHER (left engine) and  #2  AUTOFEATHER  (right  engine).    The  system  will remain   inoperative   as   long   as   either   power   lever   is retarded below 90% Ni position, unless TEST position of the  AUTOFEATHER  SWITCH  is  selected  to  disable  the power  lever  limit  switches.    The  system  is  designed  for use only during takeoff and landing and should be turned off   when   establishing   cruise   climb.      During   takeoff   or landing,  should  the  torque  for  either  engine  drop  to  an indication  between  16  21%,  the  autofeather  system  for the   opposite   engine   will   be   disarmed.      Disarming   is confirmed when the AUTOFEATHER light of the opposite engine becomes extinguished.  If torque drops further, to a  reading  between  9  and  14%,  oil  is  dumped  from  the servo   of   the   effected   propeller   allowing   a   feathering spring   and   counter-weights   to   move   the   blades   into feathered position. Feathering also causes the AUTOFEATHER    light    of    the    feathered    propeller    to extinguish. At this time, both annunciator AUTOFEATHER  lights  are  extinguished,  the  propeller  of the  defective  engine  has  feathered,  and  the  propeller  of the    operative    engine    has    been    disarmed    from    the autofeathering capability.  Only manual feathering control remains for the second propeller. b. Propeller  Autofeather  Switch.    Autofeathering  is controlled by an AUTOFEATHER switch on the overhead control   panel   (fig.      2-18).      The   threeposition   switch   is placarded   ARM,   OFF   and   TEST,   and   is   spring-loaded from TEST to OFF.  The ARM position is used only during takeoff  and  landing.    The  TEST  position  of  the  switch, enables  the  pilot  to  check  readiness  of  the  autofeather systems,   below   88%   to   92%   N1,   and   is   for   ground checkout purposes only. c. Autofeather   Lights.      Two   green   lights   on   the caution/advisory annunciator panel, placarded AUTOFEATHER #1 and #2.  When illuminated, the lights indicate that the autofeather system is armed.  Both lights will     be     extinguished     if     either     propeller     has     been autofeathered or if the system is disarmed by retarding a power lever.  Autofeather circuits are protected by one 5- ampere circuit breaker placarded 2-39