TM 55-1510-219-10 (a) External     AC     power     annunciator light.  An annunciator light placarded EXT AC PWR ON, located on the mission annunciator panel indicates that an  AC  GPU  plug  is  mated  to  the  AC  external  power receptacle and the External AC Power control switch is On. (b) External  AC  power  control  switch. A  switch  placarded  AC  EXT  POWER,  located  on  the mission control panel controls application of three phase AC power to the aircraft. Section X.  LIGHTING 2-74.  EXTERIOR LIGHTING. a. Description.        Exterior    lighting    (fig.        2-27) consists of a navigation light on top of the aft section of the  vertical  stabilizer,  one  navigation  light  on  top  and bottom of each wing tip pod, two strobe beacons, one on top of the vertical stabilizer and one on the underside of the fuselage center section, dual landing lights, one taxi light mounted on the nose gear assembly, a recognition light  located  in  each  wing  tip,  and  two  ice  lights,  one light    flush    mounted    in    each    nacelle,    positioned    to illuminate along the leading edge of each outboard wing. b. Navigation   Lights.      The   navigation   lights   are protected by a 5-ampere circuit breaker placarded NAV on    the    overhead    circuit    breaker    panel    (fig.    2-26). Control  of  the  lights  is  provided  by  a  switch  placarded NAV-ON on the overhead control panel (fig.  2-18). c. Strobe Beacons.  The  strobe beacons are dual intensity   units.      They   are   protected   by   a   15ampere circuit  breaker  placarded  BCN  on  the  overhead  circuit breaker   panel   (fig.      2-26).      Control   of   the   lights   is provided  by  a  switch  placarded  BEACONDAY-NIGHT (fig.  2-18).  Placing the switch in the DAY position will activate  the  high  intensity  white  section  of  the  strobe lights   for   greater   visibility   during   daytime   operation. Placing  the  switch  in  the  NIGHT  position  activates  the lower intensity red section of the strobe lights. d. Landing/Taxi  Lights.    Dual  landing  lights  and  a single taxi light are mounted on the nose gear assembly. The     lights     are     controlled     by     switches,     placarded LANDING  and  TAXI,  located  in  the  LIGHTS  section  of the    pilot's    subpanel.        In    addition,    these    light    are extinguished   whenever   the   landing   gear   is   retracted. The   landing/taxi   lights   circuits   are   protected   by   5- ampere  circuit  breakers  placarded  LANDING  and  TAXI respectively,   located   on   the   overhead   circuit   breaker panel    (fig.        2-26).        Additional    circuit    protection    is provided  by  35-ampere  and  15ampere  circuit  breakers on the DC power distribution panel located beneath the cockpit floor. e. Ice Lights.  The ice lights circuit is protected by a    5-ampere    circuit    breaker    placarded    ICE    on    the overhead circuit breaker panel (fig.  2-26).  Control of the lights is provided by a switch placarded ICE  on the overhead   control   panel   (fig.      2-18).      Prolonged   use during  ground  operation  may  generate  enough  heat  to damage the lens. f. Recognition  Lights.    A  RECOG  switch,  located in the pilot's subpanel LIGHTS section, controls a white recognition light in each wing tip.  When requested, this steady, bright light is used for identification in the traffic pattern.  The recognition lights circuit is protected by a 7 1/2   ampere   RECOG   circuit   breaker   located   on   the overhead circuit breaker panel (fig.  2-26). 2-75.  INTERIOR LIGHTING. Lighting systems are installed for use by the pilot and  copilot  and  by  the  passengers  in  the  cabin  area. The  lighting  systems  in  the  cockpit  are  provided  with intensity   controls   on   the   overhead   control   panel.      A switch   placarded   MASTER   PANEL   LIGHTS   on   the overhead  control  panel  (fig.   2-18)  provides  overall  on- off   control   for   all   engine   instrument   lights,   pilot   and copilot instrument lights, overhead panel lights, console and subpanel lights and the free air temperature light. a. Cockpit Lighting. (1) Flight  instrument  lights.    Each  individual flight instrument contains internal lamps for illumination. The   circuit   is   protected   by   a   7   1/2-ampere   circuit breaker  placarded  FLT  INST  on  the  overhead  circuit overhead  circuit  breaker  panel  (fig.    226).    Control  is provided  by  two  rheostat  switches  placarded  PILOT  or COPILOT   INST   LIGHTS-OFF-BRT   on   the   overhead control panel (fig.  2-18).  Turning the control clockwise from    OFF    turns    the    lights    on    and    increases    their brilliance. (2) Instrument indirect lights.  Three lights are mounted in the glareshield overhang along the top edge of  the  instrument  panel  and  provide  overall  instrument panel   illumination.      The   circuit   is   protected   by   a   5- ampere  circuit  breaker  placarded  INST  INDIRECT  on the overhead circuit breaker panel (fig.  2-26).  Control is    provided    by    a    rheostat    switch    placarded    INST INDIRECT  LIGHTS-OFF-BRT  on  the  overhead  control panel (fig.  2-18).  Turning the 2-67