S 094-031
 WARNING: REFER TO AMM 27-81-00/201 FOR LOCK INSTALLATION PROCEDURE.
_______ WORKING PERSONS MUST STAY AWAY FROM THE WING LEADING EDGE AREA. ACCIDENTAL OPERATION OF THE FLAPS CAN CAUSE INJURY TO PERSONS.
 (10) Remove safety locks where installed.
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747-400 MAINTENANCE MANUAL
 S 414-021
 WARNING:_______ MAKE SURE THAT PERSONS AND EQUIPMENT ARE CLEAR OF THE LE AND TE
 FLAPS AND FLAP DRIVE MECHANISMS BEFORE YOU MOVE THE FLAP
 CONTROL LEVER.  WITH HYDRAULIC POWER REMOVED, THE FLAPS WILL
 MOVE AUTOMATICALLY BY ELECTRICAL POWER WHEN YOU MOVE THE FLAP
 CONTROL LEVER.

 (11)
 Retract the wing leading edge flaps (AMM 27-81-00/201).

 S 414-022

 (12)
 Install the strut access door where removed (AMM 06-09-09/201).

 S 414-033

 (13)
 For center duct thermal switches, install the access doors where removed.

 S 864-023

 (14)
 Close these circuit breakers and remove DO-NOT-CLOSE tags if it is applicable:

 (a)  P6 Main Power Distribution 1) 6C5 ALTN PWR LOOP A APU FIRE/BLD DUCT OVHT 2) 6H14 APU FIRE/BLD DUCT OVHT LOOP A 3) 6H15 APU FIRE/BLD DUCT OVHT LOOP B
 S 734-030
 (15) Do the operational test of the duct leak detection system in the wing leading edge. (AMM 26-18-00/501).
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747-400 MAINTENANCE MANUAL
 THERMAL SWITCH - INSPECTION/CHECK
_________________________________
 1.  General_______
 A.  This section makes a check of the thermal switches on the wing leading edge and the engine nacelle strut area.
 B.  There are nineteen thermal switches installed in each wing leading edge along the pneumatic ducts. Seventeen switches close at 200°F and two close at 250°F (the two above each engine strut). There are also two thermal switches installed in each nacelle strut above the pneumatic manifold which close at 300°F.
 C.  The wing leading edge thermal switches are accessed by extending wing leading edge flaps. The nacelle strut thermal switches can be accessed by removing the appropriate access panels.
 TASK 26-18-02-206-001
 2.  Check Thermal Switch (Fig. 601)____________________
 A.  References
 (1)
AMM 06-09-08/201, Wing Access Doors and Panels

 (2)
AMM 27-81-00/201, Leading Edge Flap System

 (3)
IPC 26-18-01 Fig. 2

 B.  Access
 (1)  
Location Zone
 452 Nacelle Strut 1 - Torque Box
 462 Nacelle Strut 2 - Torque Box
 472 Nacelle Strut 3 - Torque Box
 482 Nacelle Strut 4 - Torque Box

 511 Leading Edge to Front Spar, Left 521 Leading Edge to Front Spar, Left 531 Leading Edge to Front Spar, Left 611 Leading Edge to Front Spar, Right 621 Leading Edge to Front Spar, Right 631 Leading Edge to Front Spar, Right

 (2)  
Access Panel 452BL Upper Midspar Pressure Relief, Engine 1 462BL Upper Midspar Pressure Relief, Engine 2 462EL Mid Lower Strut, Engine 2 472BL Upper Midspar Pressure Relief, Engine 3 472EL Mid Lower Strut, Engine 3 482BL Upper Midspar Pressure Relief, Engine 4 521AB Lower Inbord Nacelle, Left 521EB Lower Skin Leading Edge, Left 621AB Lower Inboard Nacelle, Right 621EB Lower Skin Leading Edge, Right

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747-400
MAINTENANCE MANUAL