500  Forward Airstairs Manual Operation and Resequencing 
Feb 15/68  Figure 201 (Sheet 2)  52-61-100 
Page 203 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

(2)  Pull ladders horizontally out of carriage. Use three or more men to control upper ladder while lower ladder is unfolding from under upper ladder and handrails are erecting. As inboard end of upper ladder approaches outboard end of carriage, upper ladder must be supported and controlled during its downward rotation.
WARNING:  KEEP HANDS AND BODY CLEAR OF LOWER LADDER DURING DOWNWARD ROTATION OF UPPER LADDER.
CAUTION:  DO NOT PERMIT STAIR TO FREE FALL.
NOTE:  During horizontal extension, lower ladder will be unlocked. As upper ladder rotates downward, handrail-erecting mechanism will be actuated. At full extension, lower ladder will have rotated into alignment with upper ladder and contacted ground.
F.  Fully extend carriage.
(1)  
Move carriage pinion disconnect lever to unlocked position.

(2)  
Pull airstair carriage outboard (allowing lower ladder to move along ground surface) until carriage extend stops (4, view 1) on forward and aft rails are contacted. During this final travel, carriage step cam followers (12, detail B) will engage carriage step control actuator (3, view 1) on forward and aft rails causing carriage step to elevate.

(3)  
Extend manual handrail extensions and latch extensions to handrail support brackets inside forward entry doorway.

NOTE:  After manual extension and prior to power operation of airstair, it must be retracted manually and resequenced as described in paragraphs 4 and 5.

(4)
Move carriage pinion disconnect lever to locked position prior to using airstairs.

4.  Retract Forward Airstair
A.  Check that airstair electrical connector (1, Fig. 201) has been disconnected and tagged with an operational limitation tag.
B.  Check that handrail extensions are stowed and latched to handrails.
C.  Check position of airstair.
(1)  
If stair is fully extended and contacting the ground, proceed with step D.

(2)  
If stair is partially rotated, omit step D. and use caution when proceeding with step E.

(3)  
If stair is retracted to horizontal and all upper ladder truck rollers are on horizontal track section of the rails, omit step D.

500 
52-61-100 Page 204  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Jun 20/84 

D.  Partially retract airstair carriage.
(1)  
Remove lockwire from carriage pinion disconnect lever (5, detail A) and move lever to the unlocked position.

(2)  
Push carriage inboard until the carriage step (6) moves to the full down position. Step should lie flush with top of forward and aft carriage beams.

(3)  
Engage carriage drive pinions by moving carriage pinion disconnect lever to locked position.

E.  Fully retract ladders into carriage.
(1)  Disconnect "dog" coupling (10, detail B) on actuator drive shaft (11) by gaining access through hatch of drain pan if installed.
CAUTION:  WHEN DISCONNECTING "DOG" COUPLING, SUPPORT THE STAIRS TO PREVENT FALLING, IF STAIR IS PARTIALLY ROTATED.
DO NOT ATTEMPT TO MOVE SWING ARM OUT OF WAY OR USE SWING ARM AS HANDHOLD OR IT MAY BE DAMAGED.
(2)  Manually fold and push the ladders until they are halfway into carriage. Use three or more men to control upper ladder while lower ladder is folding under upper ladder and mechanical handrails are lowering.
WARNING:  GRASP UPPER LADDER INBOARD OF LOWER LADDER LOCK MECHANISM TO PREVENT LOWER LADDER FROM CLOSING ON HANDS OR HITTING PERSONNEL RETRACTING UPPER LADDER.
NOTE:  Rotation of upper ladder will actuate the handrail mechanism and lower ladder will be locked during horizontal retraction.
(3)  
Manually pull the ladders outboard until the ballscrews (8) begin to rotate. This should occur within ten inches of movement outboard.

(4)  
Manually push the ladders inboard until ladders are fully stowed in carriage.

(5)  
Connect the "dog" coupling on actuator drive shaft.

500 
Aug 15/69  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  52-61-100 Page 205 

F.  Fully retract airstair carriage.
(1)  
Disengage carriage drive pinions by moving carriage pinion disconnected lever to unlocked position.

(2)  
Manually push the airstair inboard until carriage retract stop fittings (13, detail C) are contacted.
　
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