EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
29-11-00
ALL ú ú 01 Page 680G ú Oct 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
(b)
Make sure that all latch assemblies are installed.
(c)
Repair and adjust the latches if it is necessary (AMM 54-62-03/501).
S 416-422
CAUTION: MAKE SURE YOU LATCH THE FAIRING DOORS ON THE TRAILING EDGE
_______ CORRECTLY. DAMAGE CAN OCCUR IF THE DOORS OPEN DURING A FLIGHT.
(21) Close the doors on the trailing edge fairing (AMM 54-62-00/201).
TASK 29-11-00-796-544
14. Hydraulic System Internal Leakage Pressure Check
________________________________________________
A. General
(1)
This pressure check is an easy procedure to monitor the general internal condition of each hydraulic system. This procedure will identify a system which has more than 5 GPM of internal leakage. If a system has too much internal leakage, you can do the internal leakage check for that system. This will identify the components which have too much leakage.
(2)
You must do this pressure check with the airplane in the cruise configuration. You must motor the engine for each system at 12.2% N2 speed to supply a flow of 4.5 GPM from the engine-driven pump (EDP). With these conditions, the minimum approved pressure in the hydraulic systems 1 thru 4 is 2500 psi.
(3)
If the pressure in a hydraulic is less than the minimum approved pressure, you must do the internal leakage check for that hydraulic system. The internal leakage check will make sure the internal leakage rate is too high. It will also identify the components which have too much internal leakage. A pump which has high internal leakage (Fig. 611) or clogged pressure filters can also cause a low pressure indication.
(4)
The sequence in which you do the pressure check of the hydraulic systems is not important. All flight controls must be in the neutral position. Let the system pressure become stable before you make a record of the pressure indication.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
29-11-00
ALL ú ú 06 Page 680H ú Jun 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
CURVE BASED ON MOTORIZING ENGINE AT 12.2% N2 SPEED (EQUIVALENT TO 468 RPM EDP DRIVE SHAFT SPEED). CURVE SHOWN IS FOR A NEWLY OVERHAULED PUMP AND SHOULD BE INTERPRETED AS AN APPROX-IMATE INDICATION OF PRESSURE/LEAKAGE RATHER THAN AN EXACT RELATIONSHIP.
SYSTEM PRESSURE - PSI
System Pressure Versus System Internal Leakage
Figure 611
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
29-11-00
ALL ú ú 05 Page 680I ú Oct 18/99
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
B. References
(1)
AMM 09-11-00/201, Towing
(2)
AMM 24-22-00/201, Manual Control
(3)
AMM 71-00-00/201, Power Plant
C.
Access
(1)
Location Zones
221 Control Cabin
222 Control Cabin
D.
Prepare for the Check
S 496-545
WARNING: YOU MUST CAREFULLY INSTALL THE GROUND LOCKS IN ALL LANDING
_______ GEAR. AN ACCIDENTAL RETRACTION OF THE LANDING GEAR CAN CAUSE INJURY TO PERSONS AND DAMAGE TO EQUIPMENT.
(1)
Install the ground locks in all landing gear (AMM 09-11-00/201).
S 866-546
(2)
Supply electrical power (AMM 24-22-00/201).
S 866-547
(3)
Make sure all the autopilot switches are in the OFF position.
S 866-560
(4)
Make sure the four FLT CONTROL HYD POWER - WING switches, on the P5 Pilots' Overhead Panel, are in the NORM position.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747-400 AMM 飞机维护手册 液压 HYDRAULIC 1(80)
