SDR AALA202011259010

Service difficulty report · Sensor · Boeing 737823

Difficulty date: November 23, 2020
Submitted: November 25, 2020
Operation: Air carrier
Aircraft: N835NN
Make and model: Boeing 737823
Aircraft serial: 29577
Aircraft time: 32,744 hours, 13,292 cycles
Engine: Cfmint CFM567B273
Engine time: 29,208 hours, 11,736 cycles
System (JASC): 7320 · Fuel Controlling System
Part: Sensor
Condition: Faulty
Location: Rt Engine
Stage of operation: CR
How discovered: O
Nature of condition: J
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. RT ENGINE HAS LONG PERIODS OF N1 AND N2 FUEL FLOW FLUCTUATIONS AT FL390/.78M N1 RANGE 91.4 TO 95.0, FUEL FLOW RANGE 2.5 TO 3.1, THROTTLES SPLIT WITH AUTOTHROTTLE ON, CHANGED ALTITUDE TO FL330 WITH NO IMPROVEMENT. AT IDLE, AUTOTHROTTLE DISENGAGED AND RT ENGINE HAD SMALL POWER SURGE. REPLACED RT T12 SENSOR, IAW AMM 73-21-05, RT ELECTRONIC ENGINE CONTROLLER (AALA202011259009), IAW SIC 08L40073002, AND THRUST LEVER ANGLE RESOLVER (AALA202011259001), IAW AMM 76-11-05. OPERATIONS CHECK GOOD.