Fault Message:

None

Fault Code:

28402700

Associated CAS:

FUEL QTY DEGRADED
(Advisory)

FUEL QTY DEGRADE CAS message is displayed when the accuracy of the total fuel quantity indication can not be assured within one percent of the total fuel quantity.

• Fuel Management Quantity and Gauging Computer (FMQGC) (A47)

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

The message will be displayed on the ground if one of the following condition occurs:

1. 50% or more of the probes in a tank are contaminated or failed.
2. The tank fuel quantity gauging function has detected the following conditions for more than 3 minutes:

   1. Fuel surface pitch/roll angles are out of limit when the fuel quantity in each wing tank is less than 85% full on the ground.
   2. FMQGC can no longer assure fuel gauging accuracy.
   3. Both probes in the forward tank have failed while the center tank is not empty.

3. Total fuel quantity can not be assured to be within one percent accuracy for the following reasons:

   1. FMQGC cannot detect a density value within 60 seconds after a power-up.
   2. Densitometer fails before the FMQGC can acquire the density value after re-fueling.
   3. Multiple sensor failures (compensators or 50% or more of the fuel probes in a tank failed).
   4. Aircraft pitch and/or roll angle limit is exceeded and the total aircraft fuel quantity is greater than 66% for 60 seconds:

      • Pitch limits: +24°/-13°.
      • Rolls limits: ±5°.

   5. FMQGC channel A and B total fuel quantity indication cross check disagrees by more than 1% for more than one minute. FMQGC computer fault will be logged in the NVM. This condition will also display the FUEL QTY DEGRADE CAS message in flight.

4. Communication fault between one of the two channels between FMQGC, DAU and the PMAT.

1. Check aircraft pitch (Pitch limits: +24°/-13°) and/or roll (Rolls limits: ±5°) angles for more then 60 seconds:

   1. If aircraft is within limits, go to step 3.
   2. If aircraft is out of limit, continue with next step.

2. Level the aircraft.

   1. If system tests are good, do close out.
   2. If fault remains, continue with next step.

3. Compare FMQGC CH A and CH B fuel quantity indication individually. Using EMS CDU, select FUEL COMPUTR CH A, then CH B circuit breaker to OUT. Record fuel quantities on the Fuel Synoptic page for each channels. FMQGC CH A and CH B readings must be within 1% of the full scale tank quantity.

   1. If it is within tolerance, go to step 5.
   2. If it is out of tolerance, continue with next step.

4. Replace the FMQGC.

   1. If system tests are good, do close out.
   2. If fault remains, continue with next step.

5. Refer to CAIMS troubleshooting tasks.
6. Do close out