599  Aft Airstair Gearbox and Transfer Shaft Wear Limits 
Feb 15/79  Figure 601 (Sheet 1)  52-14-71 
Page 601

BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

Aft Airstair Gearbox and Transfer Shaft Wear Limits  501 
52-14-71 Page 602  Figure 601 (Sheet 2) BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Nov 1/73 

AFT AIRSTAIR RETRACT LIMIT SWITCH - REMOVAL/INSTALLATION
EFFECTIVITY
Airplanes With Aft Airstair
1.  General
A.  The aft airstair uses limit switches operated by cams in the transmission units. The limit switches determine the cutoff point of the ac power unit when the airstair is extended or retracted. The retract limit switch is on the forward transmission unit (Fig. 401).
2.  Equipment and Materials
A.  Ohmmeter
3.  Remove Retract Limit Switch
A.  Manually extend aft entry door and airstair and remove limit switch cover on forward
transmission unit.

B.  Disconnect switch wiring at splice.
C.  Back off locking nuts and unscrew limit switch from transmission unit (Fig. 401).
4.  Install Retract Limit Switch
A.  Manually retract aft airstair until the upper forward roller of the fuselage door frame is just entering the airstair door cam and the outside of aft door to the fuselage skin measures 1.40 + 0.10/-0.10 inches in line with the roller. (Refer to door alignment detail, Fig. 401.)
B.  Screw limit switch into forward transmission unit (Detail A, Fig. 401).
C.  Attach ohmmeter to wires A-A and A-C and screw in limit switch until continuity is just apparent.
D.  Tighten locking nuts and install lockwire.
E.  Connect switch to airplane wiring at splice.
F.  Test aft entry door and airstair (Ref 52-14-0, Aft Entry Door and Airstair).
G.  Install unit switch cover on forward transmission unit.
Feb 15/79 52-14-81 Page 401
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

Retract Limit Switch Installation  500 
52-14-81 Page 402  Figure 401 (Sheet 1) BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Feb 15/68 

500  Retract Limit Switch Installation 
May 15/68  Figure 401 (Sheet 2) BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  52-14-81 Page 403 

AFT AIRSTAIR EXTEND LIMIT SWITCH - REMOVAL/INSTALLATION
EFFECTIVITY
Airplanes With Aft Airstair
1.  General
A.  The aft airstair uses limit switches operated by cams in the transmission units. The limit switches determine the cutoff point of the ac power unit when the airstair is extended or retracted. The extend limit switch is on the aft transmission unit in the door entryway (Fig. 401).
2.  Equipment and Materials
A.  Airstair support 15.0 +1.0/-1.0 inches high
B.  Ohmmeter
C.  Bubble protractor
3.  Remove Extend Limit Switch
A.  Manually extend aft entry door and airstair.
B.  Back off locking nuts and unscrew limit switch from transmission unit (Fig. 401).
NOTE: Limit switch wiring is spliced into airplane wiring.
4.  Install Extend Limit Switch
A.  Level airplane (Ref Chapter 8, Leveling and Weighing).
B.  Manually extend airstairs.
C.  Raise airstair approximately 60 inches. Place protractor on upper segment then lower to the following position and hold.
(1)  
On airplanes using the 10-61339-4 transmission unit, lower upper segment to 33 +1 degrees from horizontal.

(2)  
On airplanes using the 10-61339-6 or -10 transmission unit , lower upper segment 21 +1 degrees from horizontal.

D.  Insert limit switch in aft transmission unit and screw in until switch just operates (Detail A, Fig. 401).
E.  Check for continuity across terminals C-NO and for no continuity across terminals C-NC of switch.
F.  Tighten locking nuts and install lockwire.
G.  Connect switch to airplane wiring.
H.  Test aft entry door and airstair (Ref 52-14-0, Adjustment/Test).
Feb 15/79 52-14-91 Page 401
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

Extend Limit Switch Installation  500 
52-14-91Page 402   Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Feb 15/68 

AFT AIRSTAIR FOLDING MECHANISM - ADJUSTMENT/TEST
EFFECTIVITY
Airplanes With Aft Airstair
1.  General
A.  Adjustment and test of the folding mechanism will normally be required only when a folding mechanism is replaced or repaired. However, the test can also be used to check for suspected faulty operation of folding mechanism.
　
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