Service difficulty report · Compensator · Boeing 737823

Difficulty date
October 5, 2019
Submitted
October 9, 2019
Operation
Air carrier
Aircraft
N811NN
Make and model
Boeing 737823
Aircraft serial
31079
Aircraft time
31,114 hours, 12,501 cycles
Part
Compensator
Part number
2020201
Condition
Unreliable
Location
Fuel System
Stage of operation
CL
How discovered
O
Nature of condition
S
Precautionary procedure
O

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

What was found

AIRCRAFT WAS GROUNDED: PILOT REPORTS FUEL IMBALANCE IN BOTH WING TANK INDICATIONS BEGAN DECREASING IMMEDIATELY AFTER T/O. LEFT WING REDUCED TO 8.59 RIGHT TO 8.12 FAIRLY RAPIDLY THEN AT A SLOWER RATE. FUEL LOG CONSISTENTLY AND INCREASINGLY BELOW PLAN. FUEL FLOW ON LEFT ENGINE CONSISTENTLY LESS THAN RIGHT, CREW CALCULATED TOTAL FUEL BURN AT APPROX 6200 LBS PER HOUR. FUEL LOG SHOWED GREATER THAN 6400 LBS PER HOUR. WING TANKS CONTINUED TO DECREASE WITH FUEL REMAING IN THE CENTER. MAINTENANCE TROUBLESHOT AND FOUND FUEL PROBES AND THE COMPENSATOR IN THE LEFT WING TESTED BAD AND PROBES AND THE COMPENSATOR ARE FAILING IN THE RIGHT WING TANK. MAINTENANCE REPLACED LEFT WING FUEL PROBES F7, 9, 10, 12 AND COMP F15 IAW AMM 28-41-21. BITE CHECK GOOD. REPLACED RIGHT WING FUEL PROBES F8, 9, 10, 12 AND COMP IAW AMM 28-41-21. BITE TEST GOOD. (SEE SDR # AALA201910079020, AALA201910099019, AALA201910099020)