TM 55-1520-240-T 9-4.4  LANDING LIGHTS (SEARCHLIGHTS) OPERATIONAL CHECK (Continued) 9-4.4 TASK RESULT CAUTION Do  not  move  SEARCHLIGHT  switch  directly from    one    direction    to    opposite    direction. Release    switch    to    center    position    before moving   it   to   a   new   direction.      Abnormally rapid switching can damage relay contacts. CHECK CIRCUIT BREAKER 1. Check that LIGHTING SLT CONT circuit If SLT CONT circuit breaker (1) is open, close it.  If it breaker (1) and SLT FIL circuit breaker (2) opens again, go to task 9-4.5. are closed. If SLT FIL circuit breaker (2) is open, close it.  If it opens again, go to task 9-4.6. 2. Check that LIGHTING SLT CONT circuit If SLT CONT circuit breaker (3) is open, close it.  If it breaker (3) and SLT FIL circuit breaker (4) opens again, go to task 9-4.7. are closed. If SLT FIL circuit breaker (4) is open, close it.  If it opens again, go to task 9-4.6. CHECK PILOT'S LANDING LIGHT 3. Set PLT SLT CONT switch or PLT SRCHLT CONTR switch (5) to ON. 4. Set and hold pilot's SEARCH LIGHT Pilot's landing light (7) shall fully extend from hous- switch (6) to EXTEND. ing (8).  If landing light (7) does not fully extend, go to task 9-4.8. 5. Set and hold pilot's SEARCH LIGHT Pilot's landing light (7) shall rotate counterclockwise switch (6) to L and then to R. and then clockwise.  If light does not rotate in both directions, go to task 9-4.9. 6. Set and hold pilot's SEARCH LIGHT Pilot's landing light (7) shall fully retract into housing switch (6) to RETRACT. (8) with lamp (9) facing down.  If light does not fully retract, or lamp is not facing down, go to task 9-4.10. 7. Set and hold pilot's SEARCH LIGHT Pilot's landing light (7) shall fully extend from hous- switch (6) to EXTEND. ing (8). CAUTION Prolonged lighting of landing light on ground will reduce its useful life. TASK RESULT 8. Set pilot's SLT-FIL switch (10) to ON. Pilot's landing light (7) shall come on.  If it does not, 9. Set pilot's SLT-FIL switch (10) to OFF.   go to task 9-4.11. Pilot's landing light (7) shall go out.  If not, replace 10.   Set PLT SLT CONT switch or PLT landing light. SRCHLT CONTR switch (5) to RETR. Pilot's landing light (7) shall fully retract into housing (8).  If light does not fully retract, go to task 9-4.12. CHECK COPILOT'S LANDING LIGHT 11.   Set CO-PLT SLT CONT switch or CPLT SRCHLT CONTR switch (11) to ON. 12.   Set and hold copilot's SEARCH LIGHT switch (6) to EXTEND.   Copilot's landing light (12) shall fully extend from housing (13).  If light does not fully extend, go to 13.   Set and hold copilot's SEARCH LIGHT task 9-4.13. switch (6) to L and then to R. Copilot's landing light (12) shall rotate counterclock- wise and then clockwise.  If light does not rotate in 14.   Set and hold copilot's SEARCH LIGHT both directions, go to task 9-4.9. switch (6) to RETRACT. Copilot's landing light (12) shall fully retract in hous- ing (13) with lamp (14) facing down.  If light does not fully retract, or lamp is not facing down, go to task 15.   Set and hold copilot's SEARCH LIGHT 9-4.10. switch (6) to EXTEND. Copilot's landing light (12) shall fully extend from housing (13). CAUTION WARNING Prolonged lighting of landing light on ground will reduce its With  17, do not look into lighted useful life. NVG landing light.  Infra-red light output can seriously injure eyes.  Use night vision goggles or feel for heat from copilot's landing light to check 16.   Set copilot's SLT-FIL switch (10) to ON.   its operation. Copilot's landing light (12) shall come on.  If it does 17.   Set copilot's SLT-FIL switch (10) to OFF.   not, go to task 9-4.14. Copilot's landing light (12) shall go out.  If not, re- 18.   Set CO-PLT SLT CONT switch or CPLT place landing light. SRCHLT CONTR switch (11) to RETR. Copilot's landing light (12) shall fully retract into housing (13).  If light does not fully retract, go to task 9-4.15. FOLLOW-ON MAINTENANCE: TM 55-1520-240-23: Battery Disconnected Electrical Power Off END OF TASK Change  9-113