SDR ASAA2017041920490

Service difficulty report · Apu · Boeing 737890

Difficulty date: April 19, 2017
Submitted: April 21, 2017
Operation: Air carrier
Aircraft: N566AS
Make and model: Boeing 737890
Aircraft serial: 35182
Aircraft time: 39,472 hours, 11,824 cycles
System (JASC): 4900 · Airborne Auxiliary Power Unit (APU) System
Part: Apu
Condition: Malfunctioned
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

APU FAULT LIGHT ILLUMINATED ON 1ST APU START ATTEMPT AT FL360. RAN QRH , FAULT LIGHT WENT OUT WITHIN 5 MINS. ACFT GROUNDED. APU BITE TEST SHOWS MSG 49-31171 FUEL CONTROL UNIT FLOW DISAGREES WITH COMMAND. APU DID START ON 2ND ATTEMPT IN FLIGHT PER SEAMC. PERFORMED FIM 49-31TASK 808, FUEL FLOW DIVIDER HYDRAULIC LOCK PROCEDURE IAW AMM 49-31-15/401. APU STARTED AND OPS NORMAL. NO OTHER FAULTS. GROUND VERIFICATION GOOD.