DOC AIRBUS | TSM A320FThe Fuel Quantity Indications, Shown on the ECAM and FQIS Displays, Fluctuate
TASK 28-42-00-810-878-A
The Fuel Quantity Indications, Shown on the ECAM and FQIS Displays, Fluctuate
A. Referenced Information
3. Fault Confirmation
Subtask 28-42-00-710-119-A
Subtask 28-42-00-810-136-A
[Rev.8 from Aug 2018]
2026.04.04 04:29:10 UTC
The Fuel Quantity Indications, Shown on the ECAM and FQIS Displays, Fluctuate
WARNING:
OBEY THE FUEL SAFETY PROCEDURES.
1. Possible Causesfuel contamination (example, water/ice or microbiological) - probe failure
- damaged harness
- FQIC [3QT]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 28-42-00-810-801-A | Fuel Quantity Indication Computer (FQIC) 3QT |
| TSM TASK 28-42-00-810-883-A | Fuel - FQI overread discrepancies in the Fuel on Board (FOB) and Fuel Used (FU) |
| AMM 12-11-28-650-003 | Pressure Refuel with Automatic Control |
| AMM 12-11-28-650-004 | Pressure Refuel with Manual Control |
| AMM 12-11-28-650-007 | Use of Magnetic Level Indicators (MLI) |
| AMM 12-31-28-660-001 | Cold Weather Maintenance - Fuel |
| AMM 12-32-28-281-001 | Drain Water Content |
| AMM 12-32-28-281-003 | Sample Fuel for Microbiological Contamination Analysis |
| AMM 28-25-00-650-001 | Pressure Defuel |
| AMM 28-25-00-650-003 | To Drain Remaining Fuel from the Wing Tanks and the Center Tank |
| AMM 28-42-15-000-001 | Removal of the Wing Tank Fuel-Quantity-Probes |
| AMM 28-42-15-000-002 | Removal of the Center Tank Fuel-Quantity-Probe |
| AMM 28-42-15-000-004 | Removal of the Center (Transfer) Tank Fuel-Quantity Probes |
| AMM 28-42-15-000-005 | Removal of the Wing Tank Fuel-Quantity Probes |
| AMM 28-42-15-400-001 | Installation of the Wing Tank Fuel-Quantity-Probes |
| AMM 28-42-15-400-002 | Installation of the Center Tank Fuel-Quantity-Probe |
| AMM 28-42-15-400-004 | Installation of the Center (Transfer) Tank Fuel-Quantity Probe |
| AMM 28-42-15-400-005 | Installation of the Fuel-Quantity-Probes |
| AMM 28-42-16-000-001 | Removal of the Cadensicon |
| AMM 28-42-16-000-002 | Removal of the Cadensicon |
| AMM 28-42-16-400-002 | Installation of the Cadensicon |
| AMM 28-42-34-000-001 | Removal of the Fuel Quantity-Indicating Computer (FQIC) |
| AMM 28-42-34-400-001 | Installation of the Fuel Quantity-Indicating Computer (FQIC) |
| 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 28-42-43-000-005 | Removal of the Wing Tank 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 28-42-43-400-005 | Installation of the Wing Tank Harness |
| AMM 28-42-43-400-006 | Installation of the Wing-Tank Inner-Cell Group A Harness |
| AMM 28-42-43-400-007 | Installation of the Wing-Tank Inner-Cell Group B Harness |
| AMM 28-42-44-000-001 | Removal of the Center Tank Harness |
| AMM 28-42-44-000-002 | Removal of the Center Tank Harness |
| AMM 28-42-44-400-001 | Installation of the Center Tank Harness |
| AMM 28-42-44-400-002 | Installation of the Center Tank Harness |
| AMM 28-42-46-000-001 | Removal of the Dualcomp |
| AMM 28-42-46-400-001 | Installation of the Dualcomp |
| AMM 28-42-47-000-001 | Removal of the Ultracomp |
| AMM 28-42-47-400-001 | Installation of the Ultracomp |
| AMM 28-42-48-000-001 | Removal of the Ultracomp |
| AMM 28-42-48-400-001 | Installation of the Ultracomp |
| AMM 31-60-00-860-001 | EIS Start Procedure |
Subtask 28-42-00-710-119-A
A. Test
(1) Read the procedure AMM 12-31-28-660-001.
(2) Do the EIS start procedure (ECAM only) AMM 31-60-00-860-001.
(a) On the ECAM control panel (CP), push (in) the FUEL pushbutton switch (P/BSW).
(b) Make sure that the FUEL page shows on the ECAM lower Display Unit (DU).
(3) At the ECAM FUEL page examine, for ten minutes, the FQI values of the FOB and each tank for fluctuations.
4. Fault Isolation(1) Read the procedure AMM 12-31-28-660-001.
(2) Do the EIS start procedure (ECAM only) AMM 31-60-00-860-001.
(a) On the ECAM control panel (CP), push (in) the FUEL pushbutton switch (P/BSW).
(b) Make sure that the FUEL page shows on the ECAM lower Display Unit (DU).
(3) At the ECAM FUEL page examine, for ten minutes, the FQI values of the FOB and each tank for fluctuations.
NOTE: If a tank FQI value fluctuates the FOB value will fluctuate.
(4) If after examination, for the specified time, the fuel tank FQIs are: - seen to fluctuate more than 2% of total fuel on board, do step (5)
- not seen to fluctuate or fluctuates less than 2%, no more maintenance work steps are necessary. Make a note in the aircraft log to record the incident.
Subtask 28-42-00-810-136-A
A. Procedure
(1) Make sure that all the applicable fuel and fuel tank scheduled servicing tasks from the Maintenance Planning Document (MPD) have been complied with.
(a) If necessary, use the methods given in AMM 12-31-28-660-001 to complete this procedure.
(b) Where applicable, start the procedure at step (2) on the fuel tank recorded in Para. 3.A.(5). and then do the other tanks.
(a) Sampled for microbiological contamination, do AMM 12-32-28-281-003.
(b) Drained of water content, do AMM 12-32-28-281-001.
(3) If you are not sure of the quantity of all the fuel in the aircraft tanks, do one of the two sub steps (a) or (b) that follow:
(a) Manual Magnetic Indicators (MMIs):
1 Use the MMI secondary direct-reading system to calculate the FOB when the aircraft is on the ground AMM 12-11-28-650-007.
2 Do step (4).
(b) The Refuel/Defuel:
1 Defuel the aircraft AMM 28-25-00-650-001.
2 Drain the remaining fuel from the fuel tanks AMM 28-25-00-650-003.
3 Refuel
a Read the Flight Manual (Ref. FM 2.04.00).
b For additives, refer to the engine installation and operating manual for the applicable aircraft engine installation (Vendors).
c Do a refuel with fuel of the correct specification and from a good (reputable) source, AMM 12-11-28-650-003 or AMM 12-11-28-650-004.
4 Do step (4).
(4) Do the test given in Para. 3.A.
(5) If the fault continues, do the procedure (Ref. TSM TASK 28-42-00-810-883).
(a) Do the test given in Para. 3.A.
(6) If the fault continues, do the procedure (Ref. TSM TASK 28-42-00-810-801).
(a) Do the test given in Para. 3.A.
Subtask 28-42-00-810-144-A ** ON A/C NOT FOR ALL (1) Make sure that all the applicable fuel and fuel tank scheduled servicing tasks from the Maintenance Planning Document (MPD) have been complied with.
(a) If necessary, use the methods given in AMM 12-31-28-660-001 to complete this procedure.
(b) Where applicable, start the procedure at step (2) on the fuel tank recorded in Para. 3.A.(5). and then do the other tanks.
NOTE: Steps (1) thru (3) must be done fully (thoroughly) to eliminate or remove (as far as is possible) the effects of fuel contamination (example, water/ice or microbiological) .
(2) If you are not sure when the fuel tanks were last: (a) Sampled for microbiological contamination, do AMM 12-32-28-281-003.
(b) Drained of water content, do AMM 12-32-28-281-001.
(3) If you are not sure of the quantity of all the fuel in the aircraft tanks, do one of the two sub steps (a) or (b) that follow:
(a) Manual Magnetic Indicators (MMIs):
1 Use the MMI secondary direct-reading system to calculate the FOB when the aircraft is on the ground AMM 12-11-28-650-007.
2 Do step (4).
(b) The Refuel/Defuel:
1 Defuel the aircraft AMM 28-25-00-650-001.
2 Drain the remaining fuel from the fuel tanks AMM 28-25-00-650-003.
3 Refuel
a Read the Flight Manual (Ref. FM 2.04.00).
b For additives, refer to the engine installation and operating manual for the applicable aircraft engine installation (Vendors).
c Do a refuel with fuel of the correct specification and from a good (reputable) source, AMM 12-11-28-650-003 or AMM 12-11-28-650-004.
4 Do step (4).
(4) Do the test given in Para. 3.A.
(5) If the fault continues, do the procedure (Ref. TSM TASK 28-42-00-810-883).
(a) Do the test given in Para. 3.A.
(6) If the fault continues, do the procedure (Ref. TSM TASK 28-42-00-810-801).
(a) Do the test given in Para. 3.A.
B. If the fault continues:
(1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
Subtask 28-42-00-810-144-B ** ON A/C NOT FOR ALL (1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
B. If the fault continues:
(1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
Subtask 28-42-00-810-144-D ** ON A/C NOT FOR ALL (1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
B. If the fault continues:
(1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
Subtask 28-42-00-810-145-A (1) Using the information recorded in Para. 3. A. (5) do a check for an applicable probe failure or damaged harness and replace if necessary.
(2) Do the test given in Para. 3.A.
C. If the fault continues:
(1) Replace the FQIC [3QT] AMM 28-42-34-000-001 and AMM 28-42-34-400-001.
(2) Do the test given in Para. 3.A.
(1) Replace the FQIC [3QT] AMM 28-42-34-000-001 and AMM 28-42-34-400-001.
(2) Do the test given in Para. 3.A.