W DOC AIRBUS | TSM A320F

Fuel Quantity/Temperature Probe 54QT1(2), Left(Right) Wing Tank

TASK 28-42-00-810-830-A
Fuel Quantity/Temperature Probe 54QT1(2), Left(Right) Wing Tank

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
  • FQIC [3QT]
  • aircraft wiring
  • Shorting plug 4043VC-A
  • Shorting plug 4044VC-A
  • water contamination
  • microbiological contamination
  • unwanted material
  • HARNESS-LEFT WING TANK A [57QT]
  • HARNESS-RIGHT WING, TANK A [58QT]
  • HARNESS-LEFT WING TANK B [63QT]
  • HARNESS-RIGHT WING TANK B [64QT]
  • PROBE-FQI NO 2 AND TEMP, RIB 1-2 L WNG TK GROUP B [54QT1]
  • PROBE-FQI NO 2 AND TEMP, RIB 1-2 R WNG TK GROUP B [54QT2]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 28-11-00-810-808-A
Fuel - Unwanted Material (Debris) In The Left (Right) Wing Fuel-Tank Collector-Cell Installation
TSM TASK 28-11-00-810-809-A
Fuel - Unwanted Material (Debris) In The Left (Right) Wing-Tank (Outboard of the Rib2)
TSM TASK 28-42-00-810-879-A
The Fuel Quantity Indications Go Inoperative Or Degraded Associated With Multiple Fuel Probe Failures Due To Water & Microbiological Contamination
AMM 12-32-28-281-001
Drain Water Content
AMM 12-32-28-281-003
Sample Fuel for Microbiological Contamination Analysis
ESPM 2052210
ESPM 2052220
ESPM 2053210
AMM 24-41-00-861-002
Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002
De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 28-10-00-910-001
Safety Procedures When You Do Work in a Fuel Tank
AMM 28-10-00-910-002
Access to the Fuel Tanks and the Work Areas
AMM 28-11-00-600-003
Removal of Microbiological Particles
AMM 28-42-00-00-
AMM 28-42-00-740-003
Interrogation of the FQIS Input Parameters Pages
AMM 28-42-00-740-009
Interrogation of the (SIMMONDS/GOODRICH) FQIS Trouble Shooting Data
AWM 284204
ASM 284205
AWM 284205
ASM 284206
ASM 284207
ASM 284208
AWM 284210
AWM 284211
AWM 284212
AWM 284213
AMM 28-42-15-000-005
Removal of the Wing Tank Fuel-Quantity Probes
AMM 28-42-15-400-005
Installation of the Fuel-Quantity-Probes
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 28-42-43-000-005
Removal of the Wing Tank Harness
AMM 28-42-43-000-008
Removal of the Wing Tank Fuel Quantity Indicating Probe Fused/Shorting Plug Connectors
AMM 28-42-43-400-005
Installation of the Wing Tank Harness
AMM 28-42-43-400-008
Installation of the Wing Tank Fuel Quantity Indicating Probe Fused/Shorting Plug Connectors
AMM 31-32-00-860-001
Procedure to Get Access to the SYSTEM REPORT/TEST Menu Page
AMM 31-60-00-860-001
EIS Start Procedure
AMM 31-60-00-860-002
EIS Stop Procedure
TSM TASK 28-42-00-03
QUANTITY INDICATING - TASK SUPPORTING DATA
3. Fault Confirmation
Subtask 28-42-00-865-076-A ** ON A/C NOT FOR ALL
A. Table of the circuit breakers used in this procedure:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUFUEL/FQI/CHAN/11QTA13
121VUFUEL/FQI/CHAN/22QTM27
Subtask 28-42-00-710-079-A ** ON A/C NOT FOR ALL
B. Test
NOTE: The FQIS is a positive DC capacitive system. In such a system the fuel probes (which are the sensors) operate as capacitors. The dielectric of the capacitors is:
  • fuel if a fuel probe is covered with fuel
  • air if a fuel probe is not covered with fuel.

Each fuel probe operates as a variable capacitor with a capacitance value related to the ratio of the fuel probe covered in air or fuel. This is because the permittivity of the fuel is approximately two times that of air. Thus the fuel is a component part of the electrical FQIS.

If water (and/or other unwanted materials) gets into a fuel-tank, it can cause problems. Example, it can cause a partial or a complete short circuit between the two concentric tubes of the fuel probe.

It is very important that the water in each fuel tank is kept to a minimum. The procedures given in the MPD and AMM must be fully completed. A failure to do so can cause the problems that follow:
  • water contamination
  • microbiological contamination
  • chemical contamination
  • local fuel-tank corrosion
  • engine corrosion
  • the engine fuel filters to become blocked
  • the aircraft is out of service for a long period some time in the future while the microbiological contamination is removed
  • possible aircraft safety issues.

The fuel-quantity/temperature probe 54QT1(2) is the source of the fuel temperature as shown (displayed) on the ECAM FUEL system page and the LEFT (RIGHT) TEMP on the input parameter page 1 (of the CFDS - FUEL menu).
   (1) If you are:

  • not sure that the AMM refuel and all the MPD scheduled servicing tasks (related to water and microbiological contamination of the fuel) have been correctly done, do the TSM procedure (Ref. TSM TASK 28-42-00-810-879)

  • sure that the AMM refuel and all the MPD scheduled servicing tasks (related to water and microbiological contamination of the fuel) have been correctly done, do step (2).
   (2) To keep the number of computer replacements (with no fault found) to a minimum, do the power on BITE test of the FQIS as follows:
NOTE: The L(R) wing tank must contain 250kg (550lb) of fuel to fully test the temperature elements of the fuel probe. This is a software requirement related to the temperature measurement but not the fuel gaging.
     (a) If the FQIS is not energized:
       1 Close the C/Bs 1QT and 2QT.
       2 Energize the Aircraft Electrical Circuits from the External Power AMM 24-41-00-861-002.
     (b) If the FQIS is energized, reset the FQIC as follows:
       1 Open the C/Bs 1QT and 2QT.
       2 Wait 10 seconds.
       3 Close the C/Bs 1QT and 2QT.
NOTE: For the FQIC to do a (new) power up BITE test, a power supply interrupt (interval) of more than 10 seconds is necessary. This gives the current status of the FQIS components.
   (3) Do the EIS Start Procedure (ECAM only) AMM 31-60-00-860-001.
   (4) On the ECAM control panel, push (in) the FUEL P/BSW.
   (5) Make sure that the FUEL page shows on the ECAM lower display unit.
   (6) Wait 60 seconds.
   (7) Continue as follows:
NOTE: The FUEL page FQIs will show XXs in amber color, for 35 seconds, during the FQIC power up BITE test.
A FQIS sensor fault must be sensed by the FQIC for 60 seconds before the applicable LRU identification is transmitted to the CFDS as unserviceable. The fault message is shown on the MCDU when set to SYSTEM REPORT/TEST (FUEL) and the FQIS STATUS page.
     (a) Do the procedure to get access to the SYSTEM REPORT/TEST menu page AMM 31-32-00-860-001.
     (b) When the SYSTEM REPORT/TEST menu page comes into view, push the line key adjacent to FUEL.
     (c) When the FUEL menu page comes into view, push the line key adjacent to FQIS STATUS.
   (8) Examine the FQIS STATUS page.
     (a) Make a record of the messages shown (or use the PRINT function to get a copy).
     (b) When you have got a copy or print, press the RETURN key on the MCDU.
     (c) When the FUEL menu page comes into view, push the line key adjacent to INPUT PARAMETERS.
   (9) Examine the INPUT PARAMETER VALUES (page 1 - FQIS INPUT PARAMETERS).
     (a) Make a record of the page 1 (or use the PRINT function to get a copy).
     (b) When you have got a copy or print, press the NEXT PAGE key on the MCDU.
   (10) Examine the INPUT PARAMETERS (page 2 - FQIS PROBE CAPACITANCES).
     (a) Make a record of the page 2 (or use the PRINT function to get a copy).
   (11) Compare the original failure and your records with those that follow:

  • if the FQI goes inoperative or degraded and is associated with multiple fuel probe failures, do the procedure (Ref. TSM TASK 28-42-00-810-879)

  • if multiple fuel probe messages are given on the FQIS STATUS page with multiple values on the I/P PARAMETER page 1 and page 2 (shown with a - (dash) or out of range (see the note below)), do the procedure (Ref. TSM TASK 28-42-00-810-879)

  • if the message L(R) QTY PROBE 54QT1(2) or L(R) QTY PROBE 54QT1(2)/WRG is shown (and/or the LEFT (RIGHT) TEMP value on the I/P PARAMETER page 1 and/or the related probe capacitance value on page 2) are shown with a - (dash) or out of range, do Para. 4.A.

  • if the message L(R) QTY PROBE 54QT1(2) or L(R) QTY PROBE 54QT1(2)/WRG is not shown and the values shown on the I/P PARAMETER pages are correct, no troubleshooting work steps are necessary.
NOTE: If the input parameter values are calculated (in the FQIC 3QT) they are shown (displayed). This is also true when the parameters are out of range. A - (dash) is shown if a parameter is not measured. Example, because of a fuel-probe sensor detector failure. Out of range values of more than the display capability are shown as the maximum value of the display.

The normal range of fuel-probe capacitance values (at dry and full) can be got from the Tank Units DC Capacitance Values 28-42-00-03 TSM TASK 28-42-00-03.
NOTE: You can get data from the:
  • Description and Operation (D and O) section of the Aircraft Maintenance Manual (AMM), the Fuel Quantity Indicating System (FQIS) AMM 28-42-00-00-
  • Trouble-shooting Manual (TSM) - Task Supporting Data (Ref. P. Block 301)
  • Aircraft Schematic Manual (ASM) ASM 284205 ( ASM 284206) and ASM 284207 ( ASM 284208).
NOTE: You can get more Trouble-shooting data from the CFDS(FUEL):
NOTE: OPTIONAL TESTING:
If a DC Capacitance Fuel System Tester is available, measurements can be taken (of the capacitive section) before a decision is made to go into or close up a fuel tank. The Tester can be connected to the FQIC rack connector or the related tank wall connector. (Ref. P. Block 301 for the Tank Units DC Capacitance Values).
4. Fault Isolation
Subtask 28-42-00-810-079-B ** ON A/C NOT FOR ALL
A. Procedure
NOTE: Where applicable, to show the difference between the left and right wing installations, the FINs given in this procedure are written as follows:
  • The left wing, no parenthesis, FIN
  • The right wing, in parenthesis, (FIN).
   (1) Temporarily replace the FQIC 3QT with a serviceable item AMM 28-42-34-000-001 and AMM 28-42-34-400-001.
NOTE: The step (1) has been included because it is important to make sure that the FQIC is serviceable before you start more steps.
   (2) If the message L(R) QTY PROBE 54QT1(2) or L(R) QTY PROBE 54QT1(2)/WRG:

  • Is not shown (and the related input parameter values show correct), complete the installation of the FQIC [3QT] AMM 28-42-34-000-001 and AMM 28-42-34-400-001

  • Is shown (and the related input parameter values stay incorrect), do step (3).
   (3) Remove the temporary installed serviceable FQIC 3QT AMM 28-42-34-000-001 and return it to stores.
   (4) Get access to the tank wall connectors 4039VC1(2)-A, 4040VC1(2)-A and the shorting plug 4043VC-A(4044VC-A) AMM 28-42-43-000-008.
   (5) Disconnect the:
  • Tank wall connector 4039VC1(2)-A
  • Tank wall connector 4040VC1(2)-A
  • Shorting plug 4043VC-A(4044VC-A).
   (6) Do a visual inspection and electrical tests of the aircraft wiring AWM 284205 ( AWM 284204) and AWM 284211 ( AWM 284210) between the FQIC rack connector 3QT-AA and the tank wall connector 4040VC1-A(4040VC2-A) as follows:
NOTE: Each capacitive fuel probe is supplied with an alternating current drive from the FQIC.
The fuel probes in a tank group (harness) share the drive and drive return (two aircraft wires) between the FQIC rack connector and the connector 4043VC-A (4044VC-A).
The connector is adjacent to and below its related tank wall connector.
In the connector:
  • The drive wire divides to supply each of the related fuel probes, in parallel
  • The drive return wire also divides to connect to each of the related fuel probes,in parallel.
All of the discrete drive and drive return wires then go to the tank wall connector 4040VC1(2)-A.
Diodes located in the terminal housing of the fuel probe half wave rectify the output signal. The positive going, dc current signal (in proportion to the capacitance value/fuel height from the fuel probe) is routed directly from the tank wall connector 4040VC1(2)-A to the FQIC rack connector.
The two (2) temperature sensors (A & B) in the wing tank fuel quantity/temperature probe 54QT1(2) are connected to the FQIC by six (6) wires. The three wires from one temperature sensor (A) are routed directly from the tank wall connector 4039VC1(2). The three wires from the other temperature sensor (B) are routed directly from the tank wall connector 4040VC1(2).
     (a) Visual Inspection
Make sure that good lighting is available.
Do a visual inspection and look for distortion (bent, pinched or stretched), damage (broken, chafed or cut), discoloration, overheating (burnt, melted or arcing), liquid contamination, loose electrical connection, or incorrect assembly of the items that follow:
NOTE: The visual inspections are grouped by wing and group.
Left Wing Group A - TEMP ELEMENT A AWM 284205
  • FQIC rack connector 3QT-AA, pins 9H, 9J and 9K
  • 92VU shelf receptacle 214VC and connector 214VC-A
  • Receptacle 1521VC and connector 1521VC-A
  • Receptacle 2973VC and connector 2973VC-A
  • Receptacle 7107VC and connector 7107VC-A
  • Pressure seal feedthrough 4015VP
  • Connector 4039VC1-A, pins N, <I and <Y
  • Adjacent and related connecting wires

Left Wing Group B - TEMP ELEMENT B and PROBE-FQI No 2 AWM 284211 and AWM 284213
  • FQIC rack connector 3QT-AA, pins 11C, 10A and 10B - temp. element
  • FQIC rack connector 3QT-AA, pins 3B, 7A and 4D - probe element
  • 92VU shelf receptacle 210VC and connector 210VC-A
  • Receptacle 1970VC and connector 1970VC-A
  • Receptacle 7155VC and connector 7155VC-A
  • Pressure seal feedthrough 4017VP
  • Shorting plug 4043VC-A and receptacle 4043VC
  • Connector 4040VC1-A, pins N, <I and <Y - temp. element
  • Connector 4040VC1-A, pins R, <J and P - probe element
  • Adjacent and related connecting wires

Right Wing Group A - TEMP ELEMENT A ASM 284206
  • FQIC rack connector 3QT-AA, pins 9B, 9C and 9D
  • 92VU shelf receptacle 210VC and connector 210VC-A
  • Receptacle 1970VC and connector 1970VC-A
  • Receptacle 7154VC and connector 7154VC-A
  • Pressure seal feedthrough 4018VP
  • Connector 4039VC2-A, pins N, <I and <Y
  • Adjacent and related connecting wires

Right Wing Group B - TEMP ELEMENT B and PROBE-FQI No 2 AWM 284210 and AWM 284212
  • FQIC rack connector 3QT-AA, pins 11J, 10G and 10H - temp. element
  • FQIC rack connector 3QT-AA, pins 4K, 7G and 5F - probe element
  • 92VU shelf receptacle 214VC and connector 214VC-A
  • Receptacle 1521VC and connector 1521VC-A
  • Receptacle 2973VC and connector 2973VC-A
  • Receptacle 7110VC and connector 7110VC-A
  • Pressure seal feedthrough 4016VP
  • Shorting plug 4044VC-A and receptacle 4044VC
  • Connector 4040VC2-A, pins N, <I and <Y - temp. element
  • Connector 4040VC2-A, pins R, <J and P - probe element
  • Adjacent and related connecting wires.
     (b) Electrical Tests
Do a continuity test ESPM 2052210 and a test for a short circuit ESPM 2052220 of the wires that follow:
NOTE: The wiring tests are grouped by wing, group and sensor.
Left Wing Group A - TEMP ELEMENT A AWM 284205
  • FQIC rack connector 3QT-AA, pin 9B to connector 4039VC1-A, pin N (HIGH)
  • FQIC rack connector 3QT-AA, pin 9C to connector 4039VC1-A, pin <I (SENSE)
  • FQIC rack connector 3QT-AA, pin 9D to connector 4039VC1-A, pin <Y (LOW)

Left Wing Group B - TEMP ELEMENT B AWM 284211
  • FQIC rack connector 3QT-AA, pin 11J to connector 4040VC1-A, pin N (HIGH)
  • FQIC rack connector 3QT-AA, pin 10G to connector 4040VC1-A, pin <I (SENSE)
  • FQIC rack connector 3QT-AA, pin 10H to connector 4040VC1-A, pin <Y (LOW)

Left Wing Group B - PROBE-FQI No 2 AWM 284211
  • FQIC rack connector 3QT-AA, pin 4K to connector 4040VC1-A, pin R (probe 2 signal)
  • FQIC rack connector 3QT-AA, pin 7G to connector 4040VC1-A, pin <J (common drive return)
  • FQIC rack connector 3QT-AA, pin 5F to connector 4040VC1-A, pin P (common drive)

Right Wing Group A - TEMP ELEMENT A AWM 284204
  • FQIC rack connector 3QT-AA, pin 9H to connector 4039VC2-A, pin N (HIGH)
  • FQIC rack connector 3QT-AA, pin 9J to connector 4039VC2-A, pin <I (SENSE)
  • FQIC rack connector 3QT-AA, pin 9K to connector 4039VC2-A, pin <Y (LOW)

Right Wing Group B - TEMP ELEMENT B AWM 284211
  • FQIC rack connector 3QT-AA, pin 11C to connector 4040VC2-A, pin N (HIGH)
  • FQIC rack connector 3QT-AA, pin 10A to connector 4040VC2-A, pin <I (SENSE)
  • FQIC rack connector 3QT-AA, pin 10B to connector 4040VC2-A, pin <Y (LOW)

Right Wing Group B - PROBE-FQI No 2 AWM 284211
  • FQIC rack connector 3QT-AA, pin 3B to connector 4040VC2-A, pin R (probe 2 signal)
  • FQIC rack connector 3QT-AA, pin 7A to connector 4040VC2-A, pin <J (common drive return)
  • FQIC rack connector 3QT-AA, pin 4D to connector 4040VC2-A, pin P (common drive).
     (c) Repair all the unserviceable wiring and connectors ESPM 2053210.
     (d) Connect the:
  • Shorting plugs 4043VC-A and 4044VC to their related receptacles AMM 28-42-43-400-008
  • Tank wall connectors 4039VC1(2)-A and 4040VC1(2)-A to their related receptacles.
     (e) Install the initial FQIC 3QT AMM 28-42-34-400-001.
     (f) Do the test given in Para. 3.B.
   (7) If the fault continues:
     (a) Do a check for water contamination as given in the procedure 'Drain Water Content' AMM 12-32-28-281-001.
     (b) Do a check (sample) for microbiological contamination AMM 12-32-28-281-003. If the results are MODERATE or HEAVY, do the applicable procedure or action AMM 28-11-00-600-003.
NOTE: Different microbiological contamination test kits are available. If no water is present in the drained sample, it is important to use a kit which can test contamination in the fuel phase. It is also important you make sure you use a kit which is correct for the timescale for the results availability.
     (c) Get access to the applicable wing-tank collector cell AMM 28-10-00-910-001 and AMM 28-10-00-910-002.
     (d) If during the steps to get access to the fuel probe you find:
       1 Microbiological contamination in the fuel-tank, do the steps that follow:
         a Make a record of what you have found in the aircraft technical log.
         b Remove all the microbiological contamination AMM 28-11-00-600-003.
       2 Debris unwanted material (example, locking wire or an aircraft fastener), do the TSM procedures that follow:
   (8) Do a check of the HARNESS-LEFT WING TANK A [57QT] ( HARNESS-RIGHT WING, TANK A [58QT] ) AWM 284205 ( AWM 284204) and replace, if necessary, AMM 28-42-43-000-005 and AMM 28-42-43-400-005.
   (9) Do a check of the HARNESS-LEFT WING TANK B [63QT] ( HARNESS-RIGHT WING TANK B [64QT] ) AWM 284211 ( AWM 284210) and replace, if necessary, AMM 28-42-43-000-005 and AMM 28-42-43-400-005.
   (10) If the harneses 57QT (58QT) and 63QT (64QT) are serviceable, replace the PROBE-FQI NO 2 AND TEMP, RIB 1-2 L WNG TK GROUP B [54QT1] ( PROBE-FQI NO 2 AND TEMP, RIB 1-2 R WNG TK GROUP B [54QT2] ) AMM 28-42-15-000-005 and AMM 28-42-15-400-005.
NOTE: The L(R) wing tank must contain 250kg (550lb) of fuel to fully test the temperature elements of the fuel probe. This is a software requirement related to the temperature measurement but not the fuel gaging.
5. Close-up
Subtask 28-42-00-942-071-A ** ON A/C NOT FOR ALL
A. Close-up and Removal of Equipment
   (1) Do the EIS Stop Procedure AMM 31-60-00-860-002.
   (2) If necessary, de-energize the aircraft electrical circuits AMM 24-41-00-862-002.
   (3) Make sure that the access panel 574BB (674BB) opened during this trouble-shooting procedure is closed.
   (4) Make sure that the work area is clean, clear of tool(s) and other items.
   (5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
[Rev.8 from Aug 2018] 2026.04.04 04:39:47 UTC
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