Installation of the Fuel-Level Sensing Control-Unit (FLSCU)

TASK 28-46-34-400-001-B
Installation of the Fuel-Level Sensing Control-Unit (FLSCU)

ZONE: 121
ZONE: 122
ZONE: 150
FIN: 47QJ ** ON A/C NOT FOR ALL
FIN: 7QJ ** ON A/C NOT FOR ALL
FIN: 9QJ ** 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	AR	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
121	AVIONICS COMPARTMENT
122	AVIONICS COMPARTMENT
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT
811

C. Referenced Information

REFERENCE	DESIGNATION
TASK 28-46-00-740-001-A	Functional (BITE) Test
Fuel Level Sensing Control Unit (FLSCU 1, 2, 3)

3. Job Set-up
Subtask 28-46-34-010-052-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Make sure that the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE is in position.
(2) Make sure that access door 811 is open.
(3) On FUEL overhead panel 40VU:

Make sure that all the pushbutton switches are released (the OFF legends come on).
Make sure that the WARNING NOTICE(S) is in position to tell persons not to operate the fuel system.

(4) On refuel/defuel control panels 800VU and 801VU, make sure that the WARNING NOTICE(S) is in position to tell persons not to refuel/defuel the fuel tanks.

Subtask 28-46-34-865-054-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
FOR FIN: 7QJ (FLSCU1)
49VU	FUEL/AFT LOW LVL/& OVFL/WING L	43QJ	A10
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	FUEL/FWD LOW LVL/WING/R	45QJ	M23
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	1QL	R25
FOR FIN: 9QJ (FLSCU2)
49VU	FUEL/AFT LOW LVL/& OVFL/WING R	44QJ	A11
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	FUEL/FWD LOW LVL/WING/L	46QJ	M22
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	2QL	R26
FOR FIN: 47QJ (FLSCU 3)
121VU	ACT1/REFUEL & SPLY	33QU	L29
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	ACT LOW LVL R	51QJ	M29
121VU	ACT LOW LVL L	52QJ	M28
121VU	ACT XFR VALVE MAN CTL	30QH	N29
121VU	ACT1/CTL & SPLY	9QH	P29
121VU	ACT PUMP SUPPLY	25QH	Q29

4. Procedure
Subtask 28-46-34-420-051-A ** ON A/C NOT FOR ALL

A. Installation of the FLSCU
(1) Remove the blanking caps from the electrical connectors (3) and (5).
(2) Install the FLSCU (1) on its rack (2).
(3) Connect the FLSCU (1) to the electrical connector (3).
(4) Attach the FLSCU (1) to its rack (2) with the knurled nut (4).

Subtask 28-46-34-865-055-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
FOR FIN: 7QJ (FLSCU1)
49VU	FUEL/AFT LOW LVL/& OVFL/WING L	43QJ	A10
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	FUEL/FWD LOW LVL/WING/R	45QJ	M23
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	1QL	R25
FOR FIN: 9QJ (FLSCU2)
49VU	FUEL/AFT LOW LVL/& OVFL/WING R	44QJ	A11
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	FUEL/FWD LOW LVL/WING/L	46QJ	M22
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	2QL	R26
FOR FIN: 47QJ (FLSCU 3)
121VU	ACT1/REFUEL & SPLY	33QU	L29
121VU	FUEL/HI/LVL/SPLY	1QJ	L25
121VU	ACT LOW LVL R	51QJ	M29
121VU	ACT LOW LVL L	52QJ	M28
121VU	ACT XFR VALVE MAN CTL	30QH	N29
121VU	ACT1/CTL & SPLY	9QH	P29
121VU	ACT PUMP SUPPLY	25QH	Q29

Subtask 28-46-34-740-051-B ** ON A/C NOT FOR ALL

C. Tests
(1) Do the BITE test of the FLSCUs (7QJ, 9QJ, 47QJ) (Ref. AMM TASK 28-46-00-740-001).

NOTE: For the FLSCU 3 only:

remove the FLSCU 1 or 2
remove the FLSCU 3
install the FLSCU 3 in the FLSCU 1 or 2 position
do the BITE test of the FLSCU 3 (Ref. AMM TASK 28-46-00-740-001)
remove the FLSCU 3
install the FLSCUs 1 or 2 and 3 in their initial position.

5. Close-up
Subtask 28-46-34-410-051-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the WARNING NOTICE(S).
(3) Close access door 811.
(4) Remove the access platform(s).

[Rev.10 from 2021] 2026.04.02 06:18:17 UTC