Main Gear Isolation Valves, Modular Package Installation 506
32-32-111 Figure 401 Sep 15/70
Page 402
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
D. Pressurize hydraulic system A (Ref Chapter 29, Hydraulic Power).
E. Open and close valve and check for hydraulic leaks.
F. Check that ground lock assemblies are installed in main and nose gear (Ref 32-00-01).
G. Close isolation valves.
H. Feel down line hoses from main gear uplock and downlock actuators.
I. Move landing gear control lever to OFF.
J. Check that there are no pressure pulses in down line hoses.
K. Move landing gear control lever to DOWN.
L. Check that there are no pressure pulses in down line hoses.
M. Open valves and lockwire handles in open position.
CAUTION: VERIFY VALVE HANDLE IS IN POSITION AS SHOWN IN FIG. 401 WITH VALVE OPEN. IF DIFFERENT, INCORRECT VALVE HANDLE ASSEMBLY MUST BE REPLACED. GEAR WILL NOT RETRACT WITH VALVE IN CLOSED POSITION.
N. Install handle stop bracket. Tighten nuts finger-tight and install cotter pins.
Q. Depressurize hydraulic system A.
506
Feb 01/95 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-32-111 Page 403
MAIN GEAR ISOLATION VALVE - REMOVAL/INSTALLATION
1. General
A. Two main gear isolation valves are located in the left main gear wheel well in the main gear isolation valve modular package. The valves are identical. The following procedure provides removal and installation instructions for either valve.
2. Equipment and Materials
A. Ground Lock Assembly - F72735 (Ref 32-00-01)
B. Skydrol Assembly Lube MCS 352 or Hydraulic Fluid, Fire-Resistant, BMS 3-11
3. Remove Main Gear Isolation Valve
A. Check that landing gear ground lock assemblies are installed in all gear (Ref 32-00-01).
B. Depressurize hydraulic system A.
C. Remove handle stop bracket (Fig. 401).
D. Remove mounting bolts and isolation valve.
E. Plug valve ports in modular package.
4. Install Main Gear Isolation Valve
NOTE: Do not interchange Ronson and Whittaker valve handles. If these valve handles are interchanged on a valve, the handle position will not correspond with valve position. Loss of hydraulic power will occur.
A. Lubricate packings lightly with assembly lube or hydraulic fluid, and install on valve (Fig. 401).
B. Remove plug in isolation valve modular package.
C. Position valve in modular package and install mounting bolts.
504
Feb 01/95 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-32-121 Page 401
D. Pressurize hydraulic system A (Ref Chapter 29, Hydraulic Power).
E. Open and close valve and check for hydraulic leaks.
F. Check that ground lock assemblies are installed in main and nose gear (Ref 32-00-01).
G. Close isolation valves.
H. Feel down line hoses from main gear uplock and downlock actuators.
I. Move landing gear control lever to OFF.
J. Check that there are no pressure pulses in down line hoses.
K. Move landing gear control lever to DOWN.
L. Check that there are no pressure pulses in down line hoses.
M. Open valves and lockwire handles in open position.
CAUTION: VERIFY VALVE HANDLE IS IN POSITION AS SHOWN IN FIG. 401 WITH VALVE OPEN. IF DIFFERENT, INCORRECT VALVE HANDLE ASSEMBLY MUST BE REPLACED. GEAR WILL NOT RETRACT WITH VALVE IN CLOSED POSITION.
N. Install handle stop bracket. Tighten nuts finger-tight and install cotter pins.
O. Depressurize hydraulic system A.
32-32-121 Feb 01/95 Page 402
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
506 Main Gear Isolation Valves Installation
Aug 15/72 Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-32-121 Page 403
NOSE GEAR EXTENSION AND RETRACTION - DESCRIPTION AND OPERATION
1. General
A. The nose gear retraction and extension system raises and lowers the nose landing gear. (See figure 1.) The gear retracts or extends simultaneously with the main gear when the landing gear control handle is moved into the UP or DN detent. The retraction mechanism includes the following components. A nose gear actuator applies the force necessary to raise or lower the gear. The nose gear actuator is attached to airplane structure forward and above the gear, and to the lower end of the upper drag brace. A nose gear lock strut assembly, driven by an actuator and held in position by spring bungees, positively locks the gear in up or down position. The lock strut consists of a lock link and lock brace assembly located between the aft bulkhead and the upper drag brace. The lock actuator is mounted on the aft bulkhead between structure and an extension on the aft end of the lock brace. The spring bungees consist of two tension springs, one on each side of the lock brace. Bungees are connected to lugs on the lock link and at the lock brace pivot point on structure.
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