Removal of the Asymmetry-Position Pick-Off Unit

TASK 27-81-18-000-001-A
Removal of the Asymmetry-Position Pick-Off Unit

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

WARNING: MAKE SURE THAT THE FLIGHT CONTROL SAFETY-LOCKS AND THE WARNING NOTICES ARE IN POSITION.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

ZONE: 522
ZONE: 622
FIN: 31CV
FIN: 32CV

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 4M (13 FT)
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	TIE WRAP
No specific	AR	WARNING NOTICE(S)
98D27803500001	1	LOCKING TOOL ZERO POS
98D27803500002	1	LOCKING TOOL ZERO POS

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
522	OUTBOARD FIXED L.E STRUCTURE
622	OUTBOARD FIXED L.E STRUCTURE
FOR [31CV] (POSITION PICK OFF UNIT)
522UB
FOR [32CV] (POSITION PICK OFF UNIT)
622UB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 27-80-00-866-005-A	Retracting the Slats on the Ground
Asymmetry-Position Pick-Off Unit 31CV (32CV)

3. Job Set-up
Subtask 27-81-18-941-050-A

A. Safety Precautions

WARNING: BEFORE YOU START WORK, YOU MUST PUT ON A SAFETY HARNESS AND ATTACH IT TO THE ACCESS PLATFORM. WITHOUT A SAFETY HARNESS, YOU CAN FALL. THIS CAN KILL YOU OR CAUSE YOU INJURY.

(1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Put WARNING NOTICE(S) in position, to tell persons not to operate the slat system.

Subtask 27-81-18-860-050-A

B. Aircraft Maintenance Configuration

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE FLIGHT CONTROLS SURFACES ARE CLEAR. MOVEMENT OF FLIGHT CONTROLS CAN CAUSE INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

(1) if you replace the APPU, fully retract the slats (Ref. AMM TASK 27-80-00-866-005).

NOTE: The APPU is self-locking and you can install it when the flap/slat system is not at zero, if:

You are to install the same APPU and its position is not changed.
There is no movement of the flap/slat system during the time the APPU is removed.

(2) Install the 98D27803500001 LOCKING TOOL ZERO POS or 98D27803500002 LOCKING TOOL ZERO POS on the flap/slat control-lever.
(3) Remove the safety collar from the circuit breakers 9CV and 11CV.

Subtask 27-81-18-865-050-A

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1	5CV	B06
** ON A/C NOT FOR ALL
49VU	FLIGHT CONTROLS/SLT/CTL AND MONG/SYS1	5CV	B01
** ON A/C ALL
121VU	FLIGHT CONTROLS/WTB/SLT/SYS2	11CV	P19
121VU	FLIGHT CONTROLS/SLT/CTL/SYS2	7CV	R21
122VU	FLIGHT CONTROLS/WTB/SLT/SYS1	9CV	S06

Subtask 27-81-18-010-050-A

D. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT) in position:
(a) FOR [31CV] (POSITION PICK OFF UNIT)
below zone 522.
(b) FOR [32CV] (POSITION PICK OFF UNIT)
below zone 622.
(2) Remove the applicable access panel:
(a) FOR [31CV] (POSITION PICK OFF UNIT)
remove the access panel 522UB.
(b) FOR [32CV] (POSITION PICK OFF UNIT)
remove the access panel 622UB.

4. Procedure
Subtask 27-81-18-020-050-A

A. Remove the Assymetry-Position Pick-Off Unit

CAUTION: MAKE MATCH MARKS ON ALL THE ELECTRICAL WIRES BEFORE YOU DISCONNECT THEM. INCORRECT CONNECTION OF WIRES WILL CAUSE DAMAGE TO EQUIPMENT.

(1) Disconnect the plug (3) from connector A and the plug (4) from connector B.
(2) Install CAP - BLANKING on the plugs (3) and (4) and connectors A and B.
(3) Hold the APPU (5), remove the bolts (6) and washers (7), then disengage and remove the APPU (5).
(4) Remove the screw (1), washer (2) and disconnect the bonding strap (13).
(5) Install a TIE WRAP (8), behind the locking plate (11), to lock the APPU (5) in position.

[Rev.10 from 2021] 2026.03.31 23:56:23 UTC