SDR ASAA2020040632586

Service difficulty report · Unknown · Boeing 737890

Difficulty date: March 31, 2020
Submitted: April 6, 2020
Operation: Air carrier
Aircraft: N529AS
Make and model: Boeing 737890
Aircraft serial: 35198
Aircraft time: 38,799 hours, 11,475 cycles
System (JASC): 4940 · APU Start/Ignition System
Part: Unknown
Condition: Malfunctioned
Location: Apu
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 FAILED START AT FL 380 TWO TIMES. FAULT LIGHT ILLUMINATED DUE TO OVERTEMP. SUCCESSFUL CSS ACCOMPLISHED AFTER FAULT LIGHT EXTINGUISHED. GROUNDED - YES. PERFORMED APU BITE TEST, CURRENT STATUS NO FAULTS. FOUND FAULT IN HISTORY FOR AN OVERTEMP SHUTDOWN MAINT MSG 49-3106. STARTED APU, OPS CK GOOD. CHECKED AND RELEASED PER MEL 49-99A. APU CSS CAPABILITY IS COMPROMISED. REF L.P. 12058907. CSS SUCCESSFUL. CLEARS MEL 49-99A.