(q)
A
747-400 MAINTENANCE MANUAL
b) Manually turn the actuator until the torque increases by 15-20 pound-inches. c) Turn the manual drive 1/2 turn counterclockwise
NOTE: The internal stops are at this point.
____Do a check of the installation of the brakes as follows:
CAUTION:_______ IN CASE THE DOOR DOES NOT OPEN, STOP IMMEDIATELY. DO
NOT OPERATE THE DOOR CONTROL SWITCH. HOLDING THE
DOOR CONTROL SWITCH MAY DAMAGE THE ACTUATOR. WAIT AT
LEAST 1 MINUTE BEFORE SECOND ATTEMPT. IF THE DOOR
STILL DOES NOT OPEN, WAIT AT LEAST 10 MINUTES BEFORE
THIRD ATTEMPT.
1) Open the door electrically or manually until the clearance between the upstop and the rotary actuator arm (View A-A, Fig. 512) at the two rotary actuator is from 4.5 to 6.5 inches.
2) During the manual or electrical operation of the lift actuator in the open direction, make sure the brakes makes clicks on the forward and aft door brakes.
NOTE: This check makes sure the brakes are installed
____ correctly. The click sounds are from the pawls that hit over the rachet teeth in the brakes. When you close the door, one pawl on each brake engages a ratchet tooth. This slips the brakes and no click sounds are heard in the closing direction.
Do a check of the torque necessary to move the lift mechanism
in the open direction.
1) Put a torque wrench into the manual drive socket of the lift actuator.
2) Turn the lift actuator in the open direction a minimum of 5 turns.
3) Make sure that the torque necessary to lift the door after
the initial movement is 56 pound-inches maximum.
Do a check of the adjustment of the door up switches as
follows:
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
CAUTION:_______ IF A POWER TOOL IS USED TO MANUALLY MOVE THE LIFT
ACTUATOR, IT MUST BE OPERATED AT 500 RPM OR LESS.
YOU MUST NOT USE MORE THAN 50 INCH-POUNDS OF TORQUE.
IF YOU USE MORE THAN 70 INCH-POUNDS, YOU CAN CAUSE
DAMAGE TO THE ACTUATOR.
1) Manually turn the lift mechanism until the clearance between the forward or aft actuator arm and the upstop is
0.20 inch (Viewn A-A, Figure 512).
NOTE: It is not necessary for the forward and aft actuator
____ arms to have 0.20 inch clearance at the same time. Do this check on the first actuator arm to get the correct clearance.
a) Make sure that the clearance between the door up switch and the actuator arm is from 0.063 to 0.071 inch (View A-A, Fig. 512).
2) Manually turn the lift mechanism until the clearance between the other actuator arm and the upstop is 0.20 inch. a) Make sure that the clearance between the door up switch
and the actuator arm is from 0.063 to 0.071 inch.
(r) Close the door electrically or manually until the midspan latch cams on the door start to engage the midspan latch pins on the body.
CAUTION: DO NOT MANUALLY DRIVE THE ACTUATOR ARMS INTO THE DOOR DOWN
_______ STOPS. YOU CAN CAUSE DAMAGE TO THE LIFT MECHANISM, IF YOU OPERATE IT AFTER THIS POINT.
(s)
Manually turn the lift mechanism in the close direction until the actuator arms touch the two door down switches (View A-A, Fig. 512).
(t)
Do a check of the torque necessary to move the hooks to the closed position as follows:
CAUTION: USE TORQUE WRENCH WITH A DIAL INDICATOR (FIG. 510) TO
_______ FIND WHEN THE ACTUATOR INTERNAL STOPS ARE TOUCHED. DO NOT USE MORE THAN 70 POUND-INCHES OF TORQUE. IF YOU USE MORE THAN 70 POUND-INCHES, YOU CAN CAUSE INTERNAL DAMAGE TO THE ACTUATOR.
1) Put torque wrenches into the hook actuator manual drive sockets. 2) Manually turn the hook actuators clockwise approximately 112 turns to the hook closed position. 3) Make sure that the torque necessary to operate the hook actuators is 25 pound-inches maximum.
(u) Do a check of the torque necessary to move the latches to the closed position as follows:
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本文链接地址：747-400 AMM 飞机维护手册 舱门 DOORS 2(103)
