TM 55-1510-220-10 2-23.  POWER LEVERS. CAUTION Moving     the     power     levers     into reverse  range  without  the  engines running   may   result   in   damage   to the reverse linkage mechanism. Two    power    levers    are    located    on    the    control pedestal  (fig.    2-8).    These  levers  regulate  power  in  the reverse,   idle,   and   forward   range,   and   operate   so   that forward    movement    increases    engine    power.        Power control   is   accomplished   through   adjustment   of   the   N1 speed    governor    in    the    fuel    control    unit.        Power    is increased when N1 RPM is increased.  The power levers also  control  propeller  reverse  pitch.    Distinct  movement (pulling up and then aft on the power lever) by the pilot is required  for  reverse  thrust.    Placarding  beside  the  lever travel  slots  reads  POWER.    Upper  lever  travel  range  is designated  INCR  (increase),  supplemented  by  an  arrow pointing  forward.    Lower  travel  range  is  marked  IDLE, LIFT  and  REVERSE.    A  placard  below  the  lever  slots reads:    CAUTION    REVERSE    ONLY    WITH    ENGINES RUNNING. 2-24.  CONDITION LEVERS. Two   condition   levers   are   located   on   the   control pedestal (fig.  2-8).  Each lever starts and stops the fuel supply,  and  controls  the  idle  speed  for  its  engine.    The levers  have  three  placarded  positions:  FUEL  CUTOFF, LO   IDLE,   and   HIGH   IDLE.      In   the   FUEL   CUTOFF position, the condition lever controls the cutoff function of its  engine-mounted  fuel  control  unit.    From  LO  IDLE  to HIGH IDLE, they control the governors of the fuel control units  to  establish  minimum  fuel  flow  levels.    LO  IDLE position sets the fuel flow rate to attain 52 to 55% (at sea level) minimum N1 and HIGH IDLE position sets the rate to   attain   70%   minimum   N1.The   power   lever   for   the corresponding  engine  can  select  N1  from  the  respective idle  setting  to  maximum  power.    An  increase  in  low  idle N1 will be experienced at high field elevation. 2-25.  FRICTION LOCK KNOBS. Four friction lock knobs (fig.  2-8) are located on the control pedestal to adjust friction drag.  One knob is below the  propeller  levers,  one  below  the  condition  levers,  and two  under  the  power  levers.    When  a  knob  is  rotated clockwise, friction restraint is increased opposing movement   of   the   affected   lever   as   set   by   the   pilot. Counterclockwise rotation of a knob will decrease friction drag thus permitting free and easy lever movement.  Two FRICTION  LOCK  placards  are  located  on  the  pedestal adjacent to the knobs. 2-26.  ENGINE FIRE DETECTION SYSTEM. a. Description.        A    flame    surveillance    system    is installed on each engine to detect external engine fire and provide  alarm  to  the  pilot.    Both  nacelles  are  monitored, each   having   a   control   amplifier   and   three   detectors. Electrical     wiring     connects     all     sensors     and     control amplifiers  to  DC  power  and  to  the  cockpit  visual  alarm units.  In each nacelle, one detector monitors the forward nacelle, a second monitors the upper accessory area, and a  third  the  lower  accessory  area.    Fire  emits  an  infrared radiation    that    will    be    sensed    by    the    detector    which monitors the area of origin.  Radiation exposure activates the relay circuit of a control amplifier which causes signal power   to   be   sent   to   cockpit   warning   systems.      An activated  surveillance  system  will  return  to  the  standby state   after   the   fire   is   out.      The   system   includes   a functional  test  switch  and  has  circuit  protection  through the   FIRE   DETR   circuit   breaker.      Warning   of   internal nacelle   fire   is   provided   as   follows:   the   red   MASTER WARNING lights on the glareshield illuminate accompanied by the illumination of a red warning light in the appropriate fire control T-handle placarded No.1 FIRE PULL   or   No.2   FIRE   PULL   (fig.      2-30).      Fire   detector circuits are protected by a single 5-ampere circuit breaker, placarded  FIRE  DETR,  located  on  the  overhead  circuit breaker panel (fig.  2-27). b.  Fire Detection System Test Switch.  One rotary switch placarded   FIRE   PROTECTION   TEST   on   the   copilot's subpanel   is   provided   to   test   the   engine   fire   detection system.  Before checkout, battery power must be on and the   FIRE   DETR   circuit   breaker   must   be   in.      Switch position DETR 1, checks the area forward of the air intake of each nacelle, including circuits to the cockpit alarm and indication  devices.    Switch  position  DETR  2,  checks  the circuits   for   the   upper   accessory   compartment   of   each nacelle.    Switch  position  DETR  3,  checks  the  circuits  for the lower accessory compartment of each nacelle.  Each numbered switch position will initiate the cockpit indications previously described. c.  Erroneous Fire Detection System Indications.  During ground   test   of   the   engine   fire   detection   system,   an erroneous indication of system fault may be encountered if   an   engine   cowling   is   not   closed   properly,   or   if   the aircraft 2-24