Installation of the Digital Flight Data Recorder (DFDR) Tray/Rack

TASK 31-33-55-400-802-A
Installation of the Digital Flight Data Recorder (DFDR) Tray/Rack

WARNING: PUT WARNING NOTICES IN THE COCKPIT TO TELL PERSONS NOT TO OPERATE THE FLIGHT CONTROLS. THE MOVEMENT OF THE TRIMMABLE HORIZONTAL STABILIZER (THS) CAN CAUSE INJURY TO PERSONS.

ZONE: 310
FIN: 5000TU ** ON A/C NOT FOR ALL

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

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE
No specific	1	MILLIOHMMETER 0.5 OHM MAX, 10 A MAX - MULTIRANGE
No specific	1	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
310	FUSLG TAIL SECTION AFT OF AFT PRESS BHD
312AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 20-28-00-912-802-A	Electrical Bonding - General Maintenance Procedure
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 31-33-55-400-002-A	Installation of the Digital Flight Data Recorder (DFDR)
Digital Flight Data Recorder (DFDR) Tray/Rack ** ON A/C NOT FOR ALL
Digital Flight Data Recorder (DFDR) Rack ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 31-33-55-860-053-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Make sure that the aircraft electrical circuits are energized (Ref. AMM TASK 24-41-00-861-002).
(2) In the cockpit, make sure that the WARNING NOTICE(S) are in position to tell persons not to operate the flight controls.

Subtask 31-33-55-865-058-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	RCDR/DFDR	7TU	K16

Subtask 31-33-55-010-055-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Make sure that the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE is in position at access door 312AR.
(2) Make sure that access door 312AR is open.
(3) Make sure that light switch 3LJ is set to the "ON" position.

4. Procedure
Subtask 31-33-55-420-053-A ** ON A/C NOT FOR ALL

A. Installation of the DFDR Tray/Rack
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Put the DFDR tray/rack (1) in position on the aircraft structure.
(4) Carefully pull the electrical connector (9) through the DFDR tray/rack (1).
(5) Put the electrical connector (9) in position and install the screws (8), the washers (10) and the nuts (11).

NOTE: There are two types of electrical connectors (9):

The electrical connector (9) that is connected with four screws (8).
The electrical connector (9) that is connected with eight screws (8).

(6) Tighten the nuts (11).
(7) Make sure that the DFDR tray/rack (1) is correctly aligned with the holes in aircraft structure.
(8) Install the screws (2) and (3), the washers (4) and (6) and the nuts (5) and (7).
(9) Tighten the nuts (5) and (7).
(10) Do the bonding procedure of the DFDR tray/rack (1) at the screws (2) (Ref. AMM TASK 20-28-00-912-802).
(11) Do a check of the maximum bonding value between (Ref. AMM TASK 20-28-00-912-802) the DFDR tray/rack (1) and the screws (2):
(a) Use the MILLIOHMMETER 0.5 OHM MAX, 10 A MAX - MULTIRANGE.
(b) Make sure that the maximum bonding value is not more than 10 milliohms.

Subtask 31-33-55-420-053-C ** ON A/C NOT FOR ALL

NOTE: There are two types of electrical connectors (9):

The electrical connector (9) that is connected with four screws (8).
The electrical connector (9) that is connected with eight screws (8).

(6) Tighten the nuts (11).
(7) Make sure that the DFDR tray/rack (1) is correctly aligned with the holes in aircraft structure.
(8) Install the screws (2) and (7), the washers (3) and (6) and the nuts (4) and (5).
(9) Tighten the nuts (4) and (5).
(10) Do the bonding procedure of the DFDR tray/rack (1) at the screws (2) (Ref. AMM TASK 20-28-00-912-802).
(11) Do a check of the maximum bonding value between (Ref. AMM TASK 20-28-00-912-802) the DFDR tray/rack (1) and the screws (2):
(a) Use the MILLIOHMMETER 0.5 OHM MAX, 10 A MAX - MULTIRANGE.
(b) Make sure that the maximum bonding value is not more than 10 milliohms.

Subtask 31-33-55-865-059-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	RCDR/DFDR	7TU	K16

5. Close-up
Subtask 31-33-55-420-055-A ** ON A/C NOT FOR ALL

A. Installation of Equipment
(1) Install the DFDR (Ref. AMM TASK 31-33-55-400-002).

Subtask 31-33-55-410-055-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Set light switch 3LJ to the "OFF" position.
(3) Close access door 312AR.
(4) Remove the access platform(s).
(5) Remove the WARNING NOTICE(S).

Subtask 31-33-55-860-055-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 00:35:12 UTC