TM 55-1510-219-10 lights  are  on.    Release  switch  and  check that all lights except those in step (a.) are extinguished. c. MASTER CAUTION and MASTER WARNING     lights-Press.          Both     lights extinguish. d. Stall    and    gear    warning    system-TEST. Check that warning horn sounds and that the   LDG   gear   control   handle   lights   (2) illuminate. 17. Fire protection system-Check as follows: a. Fire detector test switch-Rotate counterclockwise   to   check   three   DETR positions.      FIRE   PULL   handles   should illuminate in each position. Reset MASTER WARNING in each position. b. Fire detector test switch-Rotate counterclockwise   to   check   two   EXTGH positions.      SQUIB   OK   light,   associated EXTGH DISCH caution light and MASTER CAUTION LIGHT should illuminate in each position. 18. INS alignment-As required. a. Exterior power 28 VDC-Connected. b. Key lock switch-ON. c. Battery switch-ON. d. Aircraft inverters-ON. e. Mission inverters-ON. f. Mission control switch-As required. g. 3 phase A.C.  bus-RESET. Check inertial cooling for ON. h. Aircraft master avionics switch- EXTERNAL POWER i. Mode selector-ALIGN j. Data selector-DSTRK/STS Align  condition  is  shown  on  5  digit  RH  display. Align will not progress beyond 8 until present position is loaded. k. Test button-PRESS AND HOLD. All displays read 8, ROLL LIMIT, HOLD, INSERT/ADVANCE,    WY    PT,    CHG,    ALERT,    BAT, WARN,  and  READY  NAV  LAMPS  lit.    When  released, all   extinguish   except   INSERT/ADVANCE.      Insure   all malfunction codes are cleared. l. Data    selector-L/L    POS    (UTM    for    grid nav). m. Load present position. (1) Select N  or S degrees, minutes and tenths -INSERT/ADVANCE - PRESS. (2) Select E or W degrees, minutes and tenths -INSERT/ADVANCE-PRESS. NOTE Insure correct values for UTM grid spheroid   coefficients   are   loaded using UTM coordinates. WAYPOINT SELECTION a. Data selector-L/L WY PT. b. WYPT   thumb   wheel-DESIRED   WY   PT (Do not use 0). c. LAT/LONG waypoint (Deg., Min., Tenths)- LOAD. d. INSERT ADVANCE-PRESS AGAIN. Latitude  and  longitude  in  arc-seconds  relating  to tenths entered is shown. e. ARC/SEC    LAT    &    LONG    (Sec.        and Tenths)-LOAD. Repeat a thru e for each WY PT. f. Flight  plan  cross  check-Data  selector  to DIS/TIME (left display will indicate distance   between   WY   PTS   TO-FROM). Press   WY   PT   change.      Verify   logical distance between waypoints. TACAN STATION SELECTION a. Data selector-L/L WY PT. b. Simultaneously press-Keys 7 and 9. c. WY PT thumb wheel-DESIRED TACAN. d. TACAN station position-LOAD LAT/LONG. e. INSERT/ADVANCE-PRESS. Latitude  and  longitude  in  arc-seconds  relating  to  tenths entered is shown. f. ARC/SEC and Tenths-LOAD. g. INSERT/ADVANCE-PRESS. h. TACAN station altitude-LOAD (select Key 4 or 6).  Enter altitude. i. INSERT/ADVANCE-PRESS. 8-4