Service difficulty report · Compensator · Boeing 737890

Difficulty date
January 14, 2018
Submitted
January 18, 2018
Operation
Air carrier
Aircraft
N586AS
Make and model
Boeing 737890
Aircraft serial
35189
Aircraft time
39,114 hours, 11,925 cycles
Part
Compensator
Part number
2020002060211
Condition
Failed
Location
Fuel Tank
Stage of operation
NR
How discovered
O
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

RT FUEL QTY ON THE UPPER DISPLAY UNIT INTERMITTENTLY GOES BLANK ALONG WITH THE TOTALIZER. WHEN SHOWING THE INDICATIONS APPEAR NORMAL. FMC "ACT PERF INIT" PAGE FUEL QTY INDICATION APPEARS UNAFFECTED. GROUNDED - YES. RELEASED PER MEL 28-6B, RT FUEL QTY INDICATION INOP AND PER MEL 28-12B. REFUEL QTY INDICATIONS ARE INOP. ACCOMPLISHED TANK AND COMPENSATOR UNITS TEST PER AMM 28-41-21/501. FOUND TANK UNITS 3 AND 7 TO BE OVER CAPACITANCE LIMITS. TANK UNIT 7 ALSO HAS LOW RESISTANCE BETWEEN LO-Z AND HI-Z. REMOVED PANELS 632 CB AND GB PER AMM 28-11-11/401. REPLACED TANK UNITS 3 AND 7 PER AMM 28-41-21/401. TANK AND COMPENSATOR UNITS TEST NOW PASSES PER AMM 28-41-21/501. CLOSED PANELS 632 CB AND GB PER AMM 28-11-11/401. LEAK CHECKS GOOD. THE FQIS NOW OP-CHECKS GOOD PER AMM 28-41-00/501. THIS CLEARS MELS 28-6B AND 28-12B.