Service difficulty report · Fuel Sys · Boeing 737890

Difficulty date
July 16, 2016
Submitted
July 18, 2016
Operation
Air carrier
Aircraft
N597AS
Make and model
Boeing 737890
Aircraft serial
35689
Aircraft time
31,783 hours, 9,797 cycles
Part
Fuel Sys
Condition
Fluctuates
Stage of operation
CR
How discovered
O
Nature of condition
O
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

FUEL FLUCTUATIONS UP TO 800 LBS BETWEEN MAIN TANK 1 & 2 WERE OBSERVED AFTER THE CENTER TANK FUEL WAS EXHAUSTED. TOTALIZER ALSO FLUCTUATED IN CONJUNCTION WITH THE MAIN TANK FLUCTUATIONS. YOKE DID NOT DEFLECT, INDICATING NO IMBALANCE. FLUCTUATIONS WERE QUICK CYCLING IN APPROXIMATELY ONE MINUTE THEN SETTLING DOWN FOR A FEW MINUTES. FUEL TEMP -14C AT FL 380, FUEL QUANTITY 14,500 LBS. ACFT GROUNDED. PERFORMED FQIS BITE CHECK AND GROUND TEST IAW FIM 28-41 TASK 814. NO FAULTS FOUND OR LOGGED ON FQIS AND ITS HISTORY. PERFORMED A WING FUEL SUMP FROM BOTH WINGS TO CHECK FOR WATER. NO WATER FOUND. PERFORMED CROSSFEED VALVE OPS CHECK, OPS CHECKED GOOD. COULD NOT DUPLICATE.