TM 55-1520-240-T 3-1.4  PROXIMITY  SWITCH  OPERATIONAL  CHECK  (WITH    ) 3-1.4 INITIAL  SETUP Personnel Required: Applicable Configurations: Medium Helicopter Repairer With               References: Tools: TM   55-1520-240-23 Aircraft  Mechanic’s  Tool  Kit, Equipment    Condition: NSN    5180-00-323-4692 Battery Connected Jack  1214-151  or  equal Electrical Power On Materials: Aft Landing Gear Access Panels Open None TASK RESULT 1. 2. 3. Check  that  AFCS  NO.  1  DC  circuit  breaker (1)  is  closed. Check  that  AFCS  NO.  2  DC  circuit  breaker (2)  is  closed. Check   that   HYDRAULICS   MAINT   PNL If AFCS NO. 1 DC circuit breaker (1) is open, close it.  If  it  opens  again,  go  to  task  11-3.6. If AFCS NO. 2 DC circuit breaker (2) is open, close it.  If  it  opens  again,  go  to  task  11-3.11. If HYDRAULICS MAINT PNL LTS circuit breaker (3) is LTS  circuit  breaker  (3)  is  closed. CHECK LEFT PROXIMITY SWITCH 4.  Check  left  GROUND  CONTACT  light  (4). 5.  Raise   left   aft   end   of   helicopter   with   jack (6)  but  do  not  install  static  lock  (7).  Jack helicopter  until  wheel  (8)  is  off  the ground  and  shock  strut  (9)  is  fully  extend- ed. 6. Lower jack (6) until clear of helicopter and re- move it. CHECK RIGHT PROXIMITY SWITCH open,  close  it.  If  it  opens  again,  go  to  task  8-14.10. Left GROUND CONTACT light (4) shall be lit. If it is not,  go  to  task  3-1.5. Left GROUND CONTACT light (4) shall go out. If it does  not,  go  to  task  3-1.6. 7. 8. 9. Check   right   GROUND   CONTACT   light   (5). Raise  right  aft  end  of  helicopter  with  jack (6)  but  do  not  install  static  lock  (7).  Jack helicopter  until  wheel  (8)  is  off  the ground  and  shock  strut  (9)  is  fully  extend- ed. Lower jack (6) until clear of helicopter and re- Right GROUND CONTACT light (5) shall be lit. If it is not,  go  to  task  3-1.7. Right   GROUND   CONTACT   light   (5)   shall   go out.  If  it  does  not,  go  to  task  3-1.8. move it. FOLLOW-ON    MAINTENANCE: Disconnect battery. Turn  electrical  power  off. Close aft landing gear access panels. END OF TASK Change 3 3-13