Service difficulty report · Compensator · Boeing 7377H4

Difficulty date
October 18, 2025
Submitted
June 5, 2026
Operation
Air carrier
Aircraft
N479WN
Make and model
Boeing 7377H4
Aircraft serial
33990
Aircraft time
70,135 hours, 42,348 cycles
Part
Compensator
Condition
Leaking
Location
Zone 600
Stage of operation
CR
How discovered
9
Nature of condition
O
Precautionary procedure
K

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

What was found

SUSPECTED FUEL LEAK. ALSO FUEL IMBALANCE RT SIDE FIRST THEN LEFT SIDE. 5.8 AT GATE IN JAX. SUPPOSED TO LAND WITH 6.6 IN MCO. ALSO HAD 6.3 AT GATE IN JAX. IT NOW STATES 5.7? (6.6). NH 30 DAYS. HANGAR REQUEST RECORD #4196<[01] ACCOMPLISHED GVI OF MAIN WING AND CENTER TANKS PER AMM 28-11-00; NO LEAKS NOTED. ACCOMPLISHED TANK FQIS TO STICK COMPARISON CHECK PER AMM 28-41-00; FOUND THE #2 MAIN TANK OUT OF TOLERANCE. OK TO CONTINUE PER MEL 28-6-01. C/W SP# 3 & SP# 1. AUTH # 288831.;[02] PERFORMED TANK AND COMPENSATOR UNITS - FUEL QUANTITY INDICATING SYSTEM HEALTH CHECK AS PER AMM 28-41-21 AND FOUND TANK UNIT 7 BELOW NORMAL READING.;[03] FOR COMPANY CONVENIENCE; R&R FUEL QUANTITY PROCESSOR PER AMM 28-41-81. FUEL QUANTITY PROCESSOR UNIT INSTALLATION TEST REQUIRED.;[04] PERFORMED FUEL QUANTITY PROCESSOR UNIT INSTALLATION TEST PER AMM 28-41-81; NO DEFECTS NOTED AT THIS TIME.;[05] R&R'D R/W FUEL QTY COMP + F3;F4;F5;F6;F7; & F8 FUEL QTY UNITS. REF: AEROTEAMS W/O 66-25188. R/W FUEL QTY OPS CHECKS GOOD PER AMM 28-41-21.

More about the Boeing 737-7H4