S 734-034
(7)
Do the system test for the control system of the landing gear (Ref 32-31-00/501).
S 094-035
WARNING: YOU MUST CAREFULLY DO THE STEPS IN THE TASKS BELOW TO REMOVE
_______ THE DOOR LOCKS FROM THE LANDING GEAR DOORS. THE DOORS CAN CLOSE QUICKLY IF YOU DO NOT REMOVE THE DOOR LOCKS CORRECTLY. THIS CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.
(8) Do this task: "Removal of the Door Locks from the Doors for the Wing Landing Gear" (Ref 32-00-30/201).
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
32-31-04
ALL ú ú 01 Page 413 ú Feb 10/91
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
S 094-036
(9) Do this task: "Removal of the Door Locks from the Doors for the Body Landing Gear" (Ref 32-00-30/201).
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
32-31-04
ALL ú ú 01 Page 414 ú Feb 10/91
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
WING GEAR AND DOOR EXTENSION AND RETRACTION -
_____________________________________________ DESCRIPTION AND OPERATION
_________________________
1. General (Fig. 1)_______
A. The wing gear extension system raises and lowers the wing landing gear. The wing gear retracts or extends simultaneously with the body gear and with the nose gear when the landing gear control handle is moved into the UP or DN detent. The retraction mechanism is comprised of the following components. The wing gear actuator applies the force required to raise and lower the gear. The actuator works in conjunction with a walking beam to apply force to the wing gear shock strut, swinging the gear inboard and forward into the wheel well. Both the actuator and the walking beam are connected to lugs on the landing gear trunnion. The outboard ends of the actuator and walking beam pivot on a beam hanger which is attached to the airplane structure. A wing landing gear locking mechanism located on the outboard side of the wheel well locks the gear in the up position. Locking of the gear in the down position is accomplished by a downlock actuator assisted by a downlock bungee which positions an upper and lower jury strut so that the upper and lower side struts will not fold.
B. The wheel well doors are operated through linkage by a hydraulic actuator. When the landing gear control handle is placed in the DN position, hydraulic pressure through sequence valves causes the doors to open before the gear extends. After the gear is down and locked these doors close. Additional doors attached to the shock strut and operated by it complete closure of the wheel well when the gear is up as shown on figure 2.
2. Wing Gear Actuator (Fig. 3)__________________
A. The wing gear actuator provides the power required to retract and extend the wing landing gear. The actuator is a hydraulic cylinder with a force piston. Snubbing action incorporated internally in the actuator slows the movement when the limit of travel is approached in either direction. The head (cylinder) end of the actuator is attached to the pin connecting the walking beams. The piston rod end connects to a trunnion arm integral with the top of the shock strut outer cylinder, at a point outboard and below the shock strut trunnion centerline. The outboard end of the walking beam is attached to structure. The opposite end of the beam pivots on a second set of trunnion arms integral with the shock strut outer cylinder. This attachment is at a point inboard and above the shock strut trunnion centerline. The actuator and walking beam are located in the wing, outboard of the shock strut.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 起落架 LANDING GEAR 4(43)
