SDR ASAA2017110522436

Service difficulty report · Warning Light · Boeing 737990ER

Difficulty date: November 5, 2017
Submitted: November 8, 2017
Operation: Air carrier
Aircraft: N474AS
Make and model: Boeing 737990ER
Aircraft serial: 40715
Aircraft time: 9,513 hours, 3,110 cycles
System (JASC): 4900 · Airborne Auxiliary Power Unit (APU) System
Part: Warning Light
Condition: False Activation
Location: Apu
Stage of operation: NR
How discovered: 9
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

ON APU START MAINT LIGHT ILLUMINATED. ACFT GROUNDED. CHECKED APU OIL LEVEL, LEVEL FULL. STARTED APU, NO LIGHT ON. ACCOMPLISHED FIM 49-90, 804, STEP E 92 0B. APU SOFTWARE READS 491A-TUS-A51-000. MAINT LIGHT FOR LOG IS SET TO ON. ACCOMPLISHED IAW AMM 49-61-00-040-801. SET LOG LIGHT TO OFF AS REQUIRED. STARTED AND RAN APU, NO LIGHT ON. PERFORMED BITE CHECK, NO FAULTS NOTED.