(2)
AMM 29-11-00/201, Pressurize/Depressurize Main Hydraulic System
(3)
AMM 32-00-15/201, Landing Gear Door Locks
(4)
AMM 32-00-20/201, Landing Gear Downlocks
E.
Access
(1)
Location zone
144 Main Landing Gear Wheel Well (RH)
731 Main Landing Gear (LH)
741 Main Landing Gear (RH)
F.
Procedure to Install the Landing Gear Selector Valve
S 614-009
(1)
Fill the valve with hydraulic fluid. Install a plug in the hydraulic fittings.
S 434-010
(2)
Install the attach bolts (1) and washers (2) to connect the valve to the structure (Detail A).
32-31-02
ALL ú ú 01 Page 403 ú May 28/01
A
757
MAINTENANCE MANUAL
S 434-011
(3) Move the input arm onto the gear on the side of the valve and
tighten the nut.
S 864-011
(4) Make sure that pressure is removed from the left hydraulic system
and the hydraulic reservoir.
S 434-012
(5) Connect the hydraulic lines to the valve.
S 714-013
(6) Make sure the valve is installed correctly.
(a) Pressurize the left hydraulic system.
WARNING: MAKE SURE THE NOSE AND MAIN LANDING GEAR DOWNLOCKS ARE_______
INSTALLED BEFORE YOU MOVE THE LANDING GEAR CONTROL LEVER.
IF THE CONTROL LEVER IS MOVED WITHOUT THE DOWNLOCKS
INSTALLED THIS CAN CAUSE THE LANDING GEAR TO RETRACT AND
INJURE PERSONNEL AND/OR DAMAGE EQUIPMENT.
(b) Move the landing gear control lever from DN to UP several
times. Return the lever to DN.
(c) Make sure hydraulic fluid does not leak from the valve.
S 864-014
(7) Look to see that the hydraulic reservoir is at the correct level.
Fill if required (AMM 12-12-01/301).
S 094-015
WARNING: MAKE SURE YOU REFER TO AMM 32-00-15/201 FOR THE DOOR LOCK
_______ REMOVAL PROCEDURE. FAST MOVEMENT OF THE DOORS WHEN THEY CLOSE COULD CAUSE INJURY TO PERSONNEL OR DAMAGE TO EQUIPMENT.
(8) Remove the landing gear door locks and close the doors (AMM 32-00-15/201).
32-31-02
ALL ú ú 01 Page 404 ú Sep 28/00
A
757 MAINTENANCE MANUAL
MAIN GEAR EXTENSION AND RETRACTION - DESCRIPTION AND OPERATION
______________________________________________________________
1. General_______
A. The extension and retraction system for the main landing gear includes valves and actuators which retract and extend the main landing gear and operate the doors for the main landing gear. The components of the system are as follows:
(1)
Retract actuator
(2)
Door actuator
(3)
Downlock actuator
(4)
Uplock actuator
(5)
Door-operated landing gear sequence valve
(6)
Downlock-operated door sequence valve
(7)
Uplock-operated sequence valve
(8)
Truck positioner actuator
(9)
Truck positioner shuttle valve
(10)
Uplock assembly.
2. Component Details
_________________
A. Retract Actuator (Fig. 1)
________________
Retract Actuator
Figure 1
32-32-00
ALL ú ú 01 Page 1 ú Mar 20/90
A
B.
C.
D.
E.
757
MAINTENANCE MANUAL
(1) The retract actuator is a hydraulic piston-type actuator that operates hydraulically in two directions. The actuator snubs internally at each end of the piston travel. This actuator applies the force to retract and extend the landing gear. The actuator is installed in the wing, outboard of the landing gear. The head end attaches to the beam that holds the main landing gear. The rod end of the actuator attaches to the upper end of the shock strut.
Door Actuator (Fig. 2)
_____________
(1) The door actuator is also a hydraulic piston-type actuator that operates hydraulically in two directions. This actuator snubs internally at each end of the piston travel. The door actuator applies the force to open and close the door for the main landing gear. An internal mechanical lock in the head end of the actuator locks the door when it is closed. Hydraulic pressure that is applied to the actuator to open the door releases the mechanical lock. The actuator is installed near the center of the keel beam in the wheel well for the main landing gear. The head end attaches to a fitting on the keel beam. The rod end attaches to the beam that holds the center hinge on the door for the main landing gear.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：757 AMM 飞机维护手册 起落架 CHAPTER 32 - LANDING GEAR 2(40)
