SDR CALA2013100791767

Service difficulty report · Unknown · Boeing 747422

Difficulty date: October 2, 2013
Submitted: October 8, 2013
Operation: Air carrier
Aircraft: N122UA
Make and model: Boeing 747422
Aircraft serial: 29168
Aircraft time: 58,729 hours, 6,833 cycles
Engine: Pwa PW4056
System (JASC): 2421 · AC Generator-Alternator
Part: Unknown
Condition: Malfunctioned
Location: Heat Exchanger
Stage of operation: IN
How discovered: C
Nature of condition: L
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

NR 2 ENG IDG AIR OIL HEAT EXCHANGER VALVE FAIL TEST. PRESENT LEG FAULT MX MESSAGE 24529. ACCOMPLISHED 24-11 FAULT TREE CONFIG 1 PAGE 104. BLOCK 1,6,7,8,12,13. RANG WIRES FROM GCU2 DISCONNECT POS J5 TO PRESS SWITCH CON DS1611 POS B & FROM DS1611 POS A TO VALVE CONN DV350 POS H. RANG FROM GUC2 DISCONNECT F1 TO VALVE CONN DV350 POS E & CHECK ALL GNDS AD VALVE CON DV350 POS F,A,J,G.