Unwanted Fuel Transfer (Migration) Between The Outer and Inner Cells of The Same Wing When The ECAM FUEL System Page ICTV Indications Show Correct

TASK 28-15-00-810-815-A
Unwanted Fuel Transfer (Migration) Between The Outer and Inner Cells of The Same Wing When The ECAM FUEL System Page ICTV Indications Show Correct

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

WARNING: WHEN YOU DO WORK ON THE FUEL SYSTEM WIRING, YOU MUST USE TEST EQUIPMENT THAT IS APPROVED (REFER TO INTERNATIONAL OR NATIONAL SPECIFICATIONS FOR INTRINSICALLY SAFE TEST EQUIPMENT: EN50020, UL913 OR EQUIVALENT). TEST EQUIPMENT THAT IS NOT APPROVED CAN CAUSE FIRE OR AN EXPLOSION.

1. Possible Causes

VALVE-AIR INLET [161QM]
VALVE-AIR INLET [162QM]
VALVE-AIR RELEASE, L WING TK [86QM]
VALVE-AIR RELEASE, R WING TK [87QM]
Intercell Transfer Valve (ICTV) Installation at Rib 15
O-rings
Recirculation Cooling System Fuel Return Pipe Installation at Rib 15
Refuel Spill Pipe Installation at Rib 15
Refuel Gallery Installation at Rib 15
Center-Tank Vent (Pipe) Installation at Rib 15 (Left Wing Only)
PROTECTOR-OVERPRESSURE, L WING TK [102QM]
PROTECTOR-OVERPRESSURE, R WING TK [103QM]
VALVE-FLOAT VENT, L WING TK OUTR [15QM]
VALVE-FLOAT VENT, R WING TK OUTR [18QM]
VALVE-FLOAT VENT, L WING TK INR [16QM]
VALVE-FLOAT VENT, R WING TK INR [17QM]
connector 4046VC1(2), part of harness 16QT1(2)
connector 4045VC1(2), part of harness 15QT1(2)
Wing-Tank Vent Duct at Rib 15
Hydraulic Pipe 0.375 OD Blue System Pressure Installation at Rib 15
Hydraulic Pipe 0.5 OD Blue System Return Installation at Rib 15
Wing-Tank Scavenge System Jet-Pumps Supply Feed-line Installation at Rib 15
Valve-Air Inlet 161QM(162QM) Through-pipe Installation at Rib 15
RIB-15 Interfaces (Joints)
fuel tank sealant

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-12-00-810-801-A	Fuel - Unwanted Transfer From The Left Wing Tank To The Center Tank At Any Time
TSM TASK 28-12-00-810-804-A	Fuel - Tank Venting, L(R) Wing Tank (Outer Cell) Overpressure Protector 102QM(103QM) Broken
TSM TASK 28-15-00-810-803-A	Intercell XFR VALVE 27QM/70QM/9QP (Left Forward) Fault - Stays Closed When The Fuel In The Inner-cell Is At Low Level
TSM TASK 28-15-00-810-804-A	Intercell XFR Valve 28QM/71QM/11QP (Left Rear) Fault - Stays Closed When The Fuel In The Inner-cell Is At Low Level
TSM TASK 28-15-00-810-805-A	Intercell XFR Valve 29QM/72QM/10QP (Right Forward) Fault - Stays Closed When The Fuel In The Inner-cell Is At Low Level
TSM TASK 28-15-00-810-806-A	Intercell XFR Valve 30QM/73QM/12QP (Right Rear) Fault - Stays Closed When The Fuel In The Inner-cell Is At Low Level
TSM TASK 28-15-00-810-807-A	Intercell XFR Valve Failure (Left Forward) - Open When Fuel Not Low Level
TSM TASK 28-15-00-810-808-A	Intercell XFR Valve Failure (Left Rear) - Open When Fuel Not Low Level
TSM TASK 28-15-00-810-809-A	Intercell XFR Valve Failure (Right Forward) - Open When Fuel Not Low Level
TSM TASK 28-15-00-810-810-A	Intercell XFR Valve Failure (Right Rear) - Open When Fuel Not Low Level
TSM TASK 28-21-00-810-825-A	Internal Fuel Leak Which Causes a Fuel Imbalance or a Discharge From a NACA Vent During Taxi or Flight
TSM TASK 28-25-00-810-810-A	Refuel Gallery - Uncommanded Fuel Transfer From One Wing To The Other Wing
AIPC 27140525
AMM 28-11-00-790-001	Leak Test with Fuel of the Wing-Tank Outer-Cell
AMM 28-12-00-200-001	Inspection of the Tank Venting System
AMM 28-12-43-000-001	Removal of the Vent Float-Valve
AMM 28-12-43-000-002	Removal of the Vent Float-Valve
AMM 28-12-43-400-001	Installation of the Vent Float-Valve
AMM 28-12-43-400-002	Installation of the Vent Float-Valve
AMM 28-15-00-710-002	Operational Check of Individual Transfer Valves to Ensure Valve Shaft Rotates Valve to Open Position
AMM 28-15-00-740-002	Functional (BITE) Test of the Intercell Transfer Valves
ASM 281501
ASM 281502
AMM 28-15-41-000-001	Removal of the Transfer Valve
AMM 28-15-41-400-001	Installation of the Transfer Valve
AIPC 28210539
AMM 28-25-42-000-001	Removal of the Refuel Diffuser Assembly - Wing Tanks
AMM 28-25-42-400-001	Installation of the Refuel Diffuser Assembly - Wing Tanks
AMM 28-25-47-000-001	Removal of the Spill-Pipe Check-Valve
AMM 28-42-43-000-003	Removal of the Wing-Tank Outer-Cell Group A Harness
AMM 28-42-43-000-004	Removal of the Wing-Tank Outer-Cell Group B Harness
AMM 28-42-43-000-006	Removal of the Wing-Tank Inner-Cell Group A Harness
AMM 28-42-43-000-007	Removal of the Wing-Tank Inner-Cell Group B Harness
AMM 28-42-43-400-003	Installation of the Wing Tank Outer-Cell Group A Harness
AMM 28-42-43-400-004	Installation of the Wing-Tank Outer-Cell Group B Harness
AMM 28-46-00-740-001	Functional (BITE) Test
AIPC 29120522
AMM 51-76-12-300-001	Local Repair of the Fuel Tank Sealant
SRM 572134

3. Fault Confirmation
Subtask 28-15-00-865-064-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers referred to in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FUEL/FQI/CHAN/1	1QT	A13
49VU	FUEL/XFR VALVE1/WING/R	2QP	A11
49VU	FUEL/XFR VALVE1/WING/L	1QP	A10
121VU	FUEL/FQI/CHAN/2	2QT	M27
121VU	FUEL/XFR VALVE2/WING/R	4QP	M23
121VU	FUEL/XFR VALVE2/WING/L	3QP	M22

Subtask 28-15-00-710-084-A ** ON A/C NOT FOR ALL

B. Test (Prerequisite 1)
(1) Do the FLSS BITE test AMM 28-46-00-740-001.
(a) Examine the FLSS STATUS page.
Look for one (or more) of the messages that follow:

L LO LEVEL SENSOR 15QJ1
L LO LEVEL SENSOR 15QJ2
R LO LEVEL SENSOR 16QJ1
R LO LEVEL SENSOR 16QJ2
FLSCU1 7QJ
FLSCU2 9QJ.

(b) If a message(s) listed (in the step before):

is not shown, do step (2).
is shown, trouble shoot the LRU(s) before you do step (2). Refer to the Fault Symptoms, at the front of the TSM and/or chapter 28, for the related Task number.

(2) Do the Functional (BITE) Test of the Intercell Transfer Valves AMM 28-15-00-740-002.

NOTE: This test lets you check the control system of the Intercell Transfer Valve (ICTV) actuators.

NOTE: The COMMAND FLSS BITE option does not test the ICTVs.

NOTE: The ICTVs are motor driven and the electrical power for these circuits is supplied as follows:

Rear Spar, System 1 - 801PP,28VDC, ESS BUS/SHEDDABLE ASM 281502
Front Spar, System 2 - 206PP,28VDC, BUS 2 ASM 281501.

The ICTVs will not operate on battery power.

(a) Examine the FLSS STATUS page.
Look for one of the intercell transfer valve messages that follow:

XFR VALVE 27QM/70QM/9QP (left wing forward intercell)
XFR VALVE 28QM/71QM/11QP (left wing rear intercell)
XFR VALVE 29QM/72QM/10QP (right wing forward intercell)
XFR VALVE 30QM/73QM/12QP (right wing rear intercell).

(b) If a message:

is not shown, do Para. 3.C.
is shown, trouble shoot the LRU(s) before you do Para. 3.C. Refer to the Fault Symptoms List/28-CFDS for the related Task number.

Subtask 28-15-00-710-085-A ** ON A/C NOT FOR ALL

C. Test (Prerequisite 2)
(1) Do the Operational Check of Individual Transfer Valves to Ensure Valve Shaft Rotates Valve to Open Position AMM 28-15-00-710-002.

NOTE: Changes in the related inner and outer cell FQIs, on the ECAM fuel system display page, let you see if there is fuel movement or transfer. This lets you check the position of a intercell transfer valve during the test.
Examples:

if the outer-cell fuel content decreases and the inner-cell increases, the valve is open
if there is no fuel movement, the valve is closed
if the fuel movement stops, or there is a large decrease, the valve has moved to the closed position.

(a) If the fuel flow:

changes as specified, do the test in Para. 3.D.
does not change when C/B-3QP is opened and closed, do the TSM procedures (Ref. TSM TASK 28-15-00-810-809) (Ref. TSM TASK 28-15-00-810-805) and then Para. 3.D.
does not change when C/B-4QP is opened and closed, do the TSM procedures (Ref. TSM TASK 28-15-00-810-807) (Ref. TSM TASK 28-15-00-810-803) and then Para. 3.D.
does not change when C/B-2QP is opened and closed, do the TSM procedures (Ref. TSM TASK 28-15-00-810-808) (Ref. TSM TASK 28-15-00-810-804) and then Para. 3.D.

does not change when C/B-1QP is opened and closed, do the TSM procedures (Ref. TSM TASK 28-15-00-810-810) (Ref. TSM TASK 28-15-00-810-806) and then Para. 3.D.

Subtask 28-15-00-710-064-E ** ON A/C NOT FOR ALL

D. Test
(1) Read all of this paragraph before you continue or do the applicable work steps.

NOTE: When the wing-tank fuel pumps are in operation, there is a continuous flow of fuel (approximately 450 kg (1000 lb) per hour) to the scavenage jet pumps in the outer-cells. This is more than sufficient to keep the outer-cells full. When an outer-cell is full, the (more than necessary) fuel returns to the inner-cell through the spill pipe.

(2) Set, or make sure that, the aircraft fuel load on the related side is as follows AMM 28-11-00-790-001:

Outercell - Full
Innercell - Not more than a maximum of 3000 kg (6620 lb)
Center Tank - Not Applicable.

NOTE: The calculated outer-cell fuel quantities (given in Para. 4.A.) are only applicable if the surface level of the fuel in the inner-cell is lower than the bottom of Rib 15 at the end of the test. That is correct if the inner-cell fuel load is set as specified or less. The reference given is for if you want to defuel the inner-cell to empty.

(3) On the ECAM FUEL System Display page, monitor the Fuel On Board (FOB) and each of the tank (cell) FQIs. Make a record of the applicable outer-cell final FQI value. The final outer-cell FQI value can give an indication of the fuel leak location for use in Para. 4.A.

NOTE: The smallest movement (resolution) of the ECAM FQI digital display is 10 kg (20 lb). It is possible for the FQI displays to change, move up or down 10 kg (20 lb) when the aircraft is in a level attitude (with no movement).

if all the FQIs remain the same and stable, for an acceptable period, no work steps are necessary

NOTE: Acceptable period definitions are given at the end of this test.

if there is a decrease of the outer-cell FQI equal to an increase of the related inner-cell FQI, do Para. 4.A.
if the unserviceable wing shows a decrease of the outer-cell FQI (equal to the sum of an increase of the inner-cell FQIs in the same wing and the other wing) do Refuel Gallery - Uncommanded Fuel Transfer From One Wing To The Other Wing (Ref. TSM TASK 28-25-00-810-810)

NOTE: This TSM procedure tries to identify if there is a defective VALVE-AIR INLET [161QM] ( VALVE-AIR INLET [162QM] ) that stays in the open positon. This lets the related outer-cell fuel move into the refuel gallery. Gravity, and the attitude of the aircraft can cause this fuel to flow (to the down side) through the drain valve 31QM (32QM) into the left and/or right wing inner-cell.

if the unserviceable wing shows a decrease of the outer-cell FQI and the FOB decreases an equal FQI, do the Leak Test with Fuel of the Wing-Tank Outer-Cell AMM 28-11-00-790-001

NOTE: This shows an external fuel leak.

if there is an unwanted transfer from the left wing tank to the center tank, do (Ref. TSM TASK 28-12-00-810-801)

NOTE: An unwanted quantity of fuel has possibly collected in the left vent surge tank because its return system has failed. When the surface level of this fuel is above the center-tank vent-pipe outlet, gravity causes it to flow into the center tank.

if there is an unwanted internal leak (transfer) which causes a fuel imbalance or discharge from a NACA vent during taxi or flight, do (Ref. TSM TASK 28-21-00-810-825).

NOTE: This TSM procedure is about a possible defective VALVE-AIR RELEASE, L WING TK [86QM] ( VALVE-AIR RELEASE, R WING TK [87QM] ).

Acceptable Period Definitions

Acceptable Period 1
Changes in FQIs will let you see if there is a leak or transfer.
If the original (unwanted) transfer is 10 kg(20 lb)/minute) you will need to monitor the outer and inner-cell FQIs for ten minutes. The slower the leakage rate the longer the monitor time necessary to make sure that you can see (detect) its effect.

Acceptable Period 2 (For a small leakage rate)
If it is operationally possible, let the aircraft stay in a level attitude overnight and then do (repeat) step (2) the next morning (or alternatively after eight hours).

Acceptable Period 3 (For a large leakage rate)
When the decrease in the outer-cell FQI stops.

4. Fault Isolation
Subtask 28-15-00-810-064-F ** ON A/C NOT FOR ALL

A. Procedure.
(1) Troubleshooting Options.
(a) Do the work steps (2) thru (17) in the sequence given.

NOTE: The sequence of the steps is the height above the fuel-tank (cell) floor. It starts with the lowest items, the ICTVs and goes up to the wing top skin. The last step is the Rib 15 wing interface.

(b) Do the work steps (2) thru (17) in a sequence of your choice.
(c) Find the FQI of the outer-cell you recorded (as the result) at Para. 3.D.(3) in the table that follows. Then do the related step given.

Examples
If the aircraft has stayed in a level attitude (since the test in Para. 3.D) the fuel (remaining) in the outer-cell can be used as an initial guide to a possible LRU failure (or leak location) as given in the examples that follow:

if the outer-cell fuel quantity decreases to approximately zero, possibly one or two ICTVs have failed in the open position, do step (2)
if the outer-cell fuel quantity decreases to approximately 71 kg (157 lb), possibly the protector-overpressure (burst disc) has operated, do step (7)
if the outer-cell fuel quantity decreases to approximately 134 kg (295 lb), possibly the valve-float vent has failed in the open position, do step (8).

NOTE: The calculated (theoretical) outer-cell fuel quantities given are only applicable (correct) if the surface level of the fuel in the inner-cell is lower than the bottom of Rib 15 at the end of the test.

OUTER-CELL FQI kg(lb)	RIB-15 INSTALLATION/LRU	STEP
0	ICTVs	(2)
	Recirculation Return Pipe	(3)
	Spill Pipe	(4)
	Refuel Gallery	(5)
	CTR/Tank Vent (L/Wing Only)	(6)
71 (157)	Protector-Overpressure	(7)
134 (295)	Vent (Rib 15, STR 9 to 10)	(8)
134 (295)	Vent (Rib 15, STR 10 to 11)	(9)
	Connector 4046VC1(2)	(10)
	Connector 4045VC1(2)	(11)
	Wing-Tank Vent Duct between (STR13 to 14)	(12)
	Hyd Pipe 0.375 OD Blue System Pressure (between STR15 to 16)	(13)
	Hyd Pipe 0.5 OD Blue System Return (between STR14 to 15)	(14)
	Scavenge Jet Pumps Supply Pipe	(15)
120 (265)	Air Inlet Valve 161QM(162QM)	(16)
O to 750 (1653)	RIB-15 Interfaces (Joints)	(17)

NOTE: In the work step titles that follow an AIRBUS (Single Aisle Aircraft) drawing (DWG) reference is given. These can supply more specific data, if required. You can get them from Airbus OnLine Services (AOLS).

(2) The Intercell Transfer Valve (ICTV) Installation at Rib 15 (Ref. DWG D28250002)
(a) Get access to each (of the two) related ICTV installations on each side of the Rib 15 AMM 28-15-41-000-001.
(b) Physically examine the two related ICTV installations.
1 Make sure that the O-rings (between each ICTV valve and the Rib 15) are installed correctly. If necessary, remove each valve to check AMM 28-15-41-000-001 AMM 28-15-41-400-001.
2 Make sure that the sealant for each of the ICTV four attachment bolts was applied correctly and is in good condition. If necessary, re-apply the sealant.
(c) Do the test given in Para. 3.D.
(3) The Recirculation Cooling System Fuel Return Pipe Installation at Rib 15 (Ref. DWG D28250004)
(a) Physically examine the fuel-pipe connector installations on each side of the Rib 15.
1 Make sure that the O-rings (between each connector and the Rib 15) are installed correctly. If necessary, remove the connectors to check the installation is serviceable.
2 Make sure that the sealant for each of the four attachment bolts was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(4) The Refuel Spill Pipe Installation at Rib 15 (Ref. DWG D28250006)
(a) Physically examine the spill-pipe connector installation on each side of the Rib 15 AMM 28-25-47-000-001.
1 Make sure that the O-ring (between the connector and the out board side of the Rib 15) is installed correctly. If necessary, remove the connector to examine.
2 Make sure that the sealant for each of the five attachment bolts was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(5) The Refuel Gallery Installation at Rib 15 (Ref. DWG D28250003)
(a) Physically examine the refuel gallery connector installation on each side of the Rib 15 AMM 28-25-42-000-001.
1 Make sure that the O-ring (between the connector and the out board side of the Rib 15) is installed correctly.
2 If necessary, remove the connector to examine and replace AMM 28-25-42-000-001 and AMM 28-25-42-400-001.
3 Make sure that the sealant for each of the four attachment bolts was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(6) The Center-Tank Vent (Pipe) Installation at Rib 15 (Left Wing Only) (Ref. DWG D28150109)
(a) Physically examine the center-tank vent connector installation on each side of the Rib 15.
1 Make sure that the O-ring (between the connector and the out board side of the Rib 15) is installed correctly.
2 If necessary, remove the connector to examine and replace.
3 Make sure that the sealant for each of the four attachment bolts was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(7) The Protector-Overpressure (Ref. DWG D28150006)
(a) Do a check of the PROTECTOR-OVERPRESSURE, L WING TK [102QM] ( PROTECTOR-OVERPRESSURE, R WING TK [103QM] ) (Ref. TSM TASK 28-12-00-810-804).
(b) Do the test given in Para. 3.D.
(8) The Outer-cell Vent System outboard of STA8262/Rib 15 (between STR 9 & 10) Outer-cell (Ref. DWG D28150101)
(a) Do a visual inspection AMM 28-12-00-200-001 of the VALVE-FLOAT VENT, L WING TK OUTR [15QM] ( VALVE-FLOAT VENT, R WING TK OUTR [18QM] ) and replace, if necessary, AMM 28-12-43-000-001 and AMM 28-12-43-400-001.
1 Make sure that the items that follow are serviceable and installed correctly:

O-ring
sealant.

2 Make sure that the vent float valves 15QM (18QM) condition is as given in AMM 28-12-00-200-001.
3 Repair/replace all the unserviceable items.
(b) Do the test given in Para. 3.D.
(9) The Inner-cell Vent System inboard of STA8262/Rib 15 (between STR 10 & 11) Inner-cell (Ref. DWG D28150101)
(a) Do a visual inspection AMM 28-12-00-200-001 of the VALVE-FLOAT VENT, L WING TK INR [16QM] ( VALVE-FLOAT VENT, R WING TK INR [17QM] ) and replace, if necessary, AMM 28-12-43-000-002 and AMM 28-12-43-400-002.
1 Make sure that the items that follow are serviceable and installed correctly:

O-ring
sealant.

2 Make sure that the vent float valves 16QM (17QM) condition is as given in AMM 28-12-00-200-001.
3 Repair/replace all the unserviceable items.
(b) Do a visual inspection of the adaptor assembly between the applicable vent float valve and the Rib 15. Replace, if necessay.
1 Make sure that the items that follow are serviceable and installed correctly:

O-ring
sealant.

(c) Do the test given in Para. 3.D.
(10) The connector 4046VC1(2), part of harness 16QT1(2) (Ref. DWG D28450007)
(a) Get access to the connector 4046VC1(2) AMM 28-42-43-000-007 and AMM 28-42-43-000-004.
(b) Do a visual inspection of the:

connector 4046VC1(2)
related installation items and sealant.

(c) Replace, if necessary, the outer-cell harness 16QT 1(2) AMM 28-42-43-000-004 and AMM 28-42-43-400-004.
(d) Do the test given in Para. 3.D.
(11) The connector 4045VC1(2), part of harness 15QT1(2) (Ref. DWG D28450007)
(a) Get access to the connector connector 4045VC1(2) AMM 28-42-43-000-006 and AMM 28-42-43-000-003.
(b) Do a visual inspection of the:

connector 4045VC1(2)
related installation items and sealant.

(c) Replace, if necessary, the outer-cell harness 15QT 1(2) AMM 28-42-43-000-003 and AMM 28-42-43-400-003.
(d) Do the test given in Para. 3.D.
(12) The Wing-Tank Vent Duct at Rib 15 (Ref. DWG D28150109) and (Ref. DWG D28150101).
(a) Examine the wing-tank (stringer) vent-duct, as given in the procedure Inspection of the Tank Venting System AMM 28-12-00-200-001, in the areas that follow:
1 Where it goes through the Rib 15 (look from the inboard and outboard sides).
2 All of its length between the Ribs 15 and 22.
3 The vent pipe from the Rib 15, that connects the applicable vent float valve 16QM (17QM), to the vent-duct between the Ribs 17 and 18.

if damage is found, contact AIRBUS.

(13) The Hydraulic Pipe 0.375 OD Blue System Pressure Installation at Rib 15 (between STR 15 & 16) (Ref. DWG D93450030) (Ref. DWG D29150006) and AIPC 27140525
(a) Examine the through connector installation and replace, if necessary.
1 Make sure that the sealant was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(14) The Hydraulic Pipe 0.5 OD Blue System Return Installation at Rib 15 (between STR 14 & 15) (Ref. DWG D93450030) (Ref. DWG D29150005) and AIPC 29120522
(a) Examine the through connector installation and replace, if necessary.
1 Make sure that the sealant was applied correctly and is in good condition. If necessary, re-apply the sealant.
(b) Do the test given in Para. 3.D.
(15) The Wing-Tank Scavenge System Jet-Pumps Supply Feed-line Installation at Rib 15 (Ref. DWG D28250007)
(a) Examine the right-angle (elbow) connector AIPC 28210539 and replace, if necessary.
(b) Do the test given in Para. 3.D.
(16) The Valve-Air Inlet 161QM(162QM) Through-pipe Installation at Rib 15 (Ref. DWG D28250003) and (Ref. DWG D28250241)
(a) Do the TSM procedure (Ref. TSM TASK 28-25-00-810-810).
(b) If the fault continues, examine the Rib-15 at the vent pipe through-point.
(c) Replace or remake the through connection as necessary.
(d) Do the test given in Para. 3.D.
(17) The RIB-15 Interfaces (Joints) (Ref. DWG D57252315)
(a) Do leak test of the outer-cell AMM 28-11-00-790-001.
1 If necessary, examine the Rib 15 joints to the structures that follow for damage (that could possibly cause a leak):

upper wing-skin
lower wing-skin
front spar
rear spar.

if the Rib 15 is found to be damaged, go to SRM 572134
if necessary, do a local repair of the fuel tank sealant AMM 51-76-12-300-001.

(b) Do the test given in Para. 3.D.

[Rev.8 from Aug 2018] 2026.04.04 04:28:30 UTC