SDR CALA2013100991923

Service difficulty report · Controller · Boeing 777222

Difficulty date: October 8, 2013
Submitted: October 10, 2013
Operation: Air carrier
Aircraft: N776UA
Make and model: Boeing 777222
Aircraft serial: 26937
Aircraft time: 71,833 hours, 12,617 cycles
Engine: Pwa PW4077
System (JASC): 4960 · APU Controls
Part: Controller
Condition: Malfunctioned
Location: Apu
Stage of operation: NR
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 CONTROL STATUS MESSAGE. MAT SHOWS MX MESSAGE 49-12 960 GEN FILT BYPASS VLV SWITCH LUBE CLUSTER CIRCUIT SHORTED. UNLATCHED & ERASED FAULT BUT SYSTEM MESSAGE RETURNED ON APU START. DEFERRED IAW MEL AFTER VLV SWITCH REPLACED STILL HAVE APU CONTROL STATUS MESSAGE DISPLAYED WHEN APU SWITCH TO ON AFTER 15 SECONDS. REPLACED APU CONTROL IAW MM49-61-05. STARTED APU 3 TIMES & NO STATUS, NO ACTIVE MESSAGE ON MAT. CHECKED HARNESS & OK. REPLACED BYPASS VLV SWITCH IAW MM49-27-15