52-31-00
ALL ú ú 02 Page 537 ú Oct 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
S 215-154
(8) Look to see the blue DOOR UP light goes off.
NOTE: The blue DOOR UP light goes off after you hold the control
____
switches for approximately 20 seconds.
S 215-155
(9)
Make sure it does not take more than 122 seconds to fully close the door from the fully open position.
S 835-156
(10)
Make sure you can install the 0.250 inch (6.35 mm) diameter rig pin in the 0.312 (7.92 mm) rig pin hole on the aft end of the linear actuator.
NOTE: The difference between 0.312 inch (7.92 mm) Rig position and
____ the 0.250 inch (6.35 mm) Operation position is a measure of the limit switch repeatibility and the motor coast due to the break slippage.
S 085-157
(11)
Remove the rig pin.
S 215-158
(12)
Look to see these indications:
(a)
On the door latch annunciator panel,
16 green LATCHED lights come on.
(b)
On the door closed annunciator panel,
2 green CLOSED lights come on.
(c)
On the door control and lights panel,
Blue DOOR UP light remains off.
N.
Put the Airplane Back To Its Usual Condition
(1)
Make sure the door is fully closed, latched and locked.
S 865-159
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
52-31-00
ALL ú ú 02 Page 538 ú Oct 18/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
S 865-175
(2)
Remove the electrical power, if it is not necessary.
S 095-176
(3)
Remove the safety barrier across the door opening.
TASK 52-31-00-725-178
5. Pressure Switch and Isolation Relay Test
________________________________________
A. General
(1)
Do this test to make sure the pressure switch and the zener diodes in the isolation circuit operate correctly.
(2)
The test is to make sure the pressure switch (S110) and the isolation relay (R1104) will completely isolate all the control circuits (electrical power) from the nose door control system (latch actuators) when the airplane is pressurized or the pressure difference between the cabin and ambient is more than 12 inches of water pressure (0.433 psi). This is a simulation test of the airplane in the flying condition.
(3)
This is a scheduled maintenance task.
B.
References
(1)
AMM 34-11-00/201, Pitot-Static System - Maintenance Practices
C.
Standard Tools and Equipment
(1)
Voltage Power Supply Probe - 0 to 65 volts DC range.
D.
Access
(1)
Location Zone
801 Nose Cargo Door
E.
Procedure
S 865-179
(1)
Make sure the nose cargo door is closed and latched.
S 215-180
(2)
Hold the SYSTEM POWER switch in the ON position and look to see this indication:
(a)
On the door control and lights panel, 1) White POWER ON light comes on 2) Green LATCHES CLOSED light comes on.
(3)
Release the switch.
S 215-181
NOTE: Green LATCHES CLOSED light will remain on after the
____
SYSTEM POWER switch is released.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú 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 舱门 DOORS 2(21)