(18)
 Do a check of the midspan latch adjustment.

 S 726-027
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747-400
MAINTENANCE MANUAL

 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.
 (a)  
Open the door electrically to get access to the midspan latches.

 (b)  
Make sure the midspan latch cams can move freely.

 (c)  
Make sure the midspan latch cams engage the midspan latch pins freely.

 (d)  
Make sure the clearance between the midspan latch pin and the midspan latch cam is from 0.31 to 0.35 inches (Detail D).

 S 826-032
 (19)
 Adjust the midspan latch pin fittings if it is necessary (Ref 52-32-00/501).

 S 226-011

 (20)
 Do a check of the latches open switch.

 NOTE: Do the check after the actuator operates electrically.
____
 S 416-073
 (21)
 Fully close the door.

 S 416-070

 (22)
 Open the door electrically approximately 1 to 2 feet (until the latch operation stops).

 S 826-060

 (23)
 Use a torque wrench with a dial indicator to manually drive the latch actuator in a OPEN (counterclockwise) direction.

 S 826-061

 (24)
 Carefully count the number of turns that remain until the external stops are contacted.

 S 826-062

 (25)
 The external stops must be contacted in 3 | 1 turns.

 S 826-074

 (26)
 If the external stops are not contacted in 3 | 1 turns, do these steps:

 (a)  
Subtract the actual number of turns that remain from the 3 turns.

 (b)  
Subtract the differnce from 8 | 1/4 turns.

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747-400 MAINTENANCE MANUAL
 (c)  Do the initial latches open switch adjustment and use this number of turns value.
 S 426-063
 (27)
 If the switch was adjusted, install the lockwire and locknuts.

 S 726-028

 (28)
 Do a check of the hook open switches.

 NOTE: Do the check after the actuator operates electrically.
____
 S 416-064
 (29)
 Hold the door control switch to the OPEN position until the lift mechanism starts to lift the door open. This will put the hooks and latches in the open in-sequence position.

 S 826-065

 (30)
 Use a torque wrench with a dial indicator to manually drive the hook actuator in a OPEN (counterclockwise) direction.

 S 826-066

 (31)
 Make sure you can turn the torque wrench from 2 to 4 turns before the actuator contacts the internal stops.

 NOTE: The actuator has contacted the stops when the torque
____ increases 15 to 20 pound-inches during one-half turn of the wrench.
 S 826-067
 (32)
 If the internal stop is not contacted in 2 to 4 turns, adjust the switch as follows:

 (a)  
Subtract the actual number of turns remaining from the 3 turns required.

 (b)  
Add this number to 7 turns.

 (c)  
Set the hook open switches to operate at this point.

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