# SDR CALA2013100191616

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 30, 2013
- Submitted: October 3, 2013
- Operation: Air carrier
- Aircraft: [N122UA](https://openairdocs.org/aircraft/N122UA), registered now
- Make and model: Boeing 747422
- Aircraft serial: 29168
- Aircraft time: 58,729 hours, 6,833 cycles
- Engine: Pwa PW4056
- System (JASC): [7900 · Engine Oil System (Airframe Furnished)](https://openairdocs.org/jasc/7900)
- Part: Unknown
- Condition: Malfunctioned
- Location: Nr 2 Engine
- Stage of operation: IN
- How discovered: C
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2013100191616

## Discrepancy

NR 2 ENG IDG AIR OIL HEAT EXCHANGER VALVE FAILED TEST.  PRESENT LEG FAULT MAINT MSG 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 & CHECKED ALL GNDS AD VALVE CON DV350 POS F,A,J,G.  REPLACED HPC SECONDARY FLOW CONTROL VALVE SOLENOID IAW AMM 75-33-04-401 & IDG AIR-OIL HEAT EXCHANGER ASSEMBLY IAW AMM 24-11-15-401, NO HELP.  LATEST EXISTING FAULT FAILURE INDICATES "IDG-2 COOLER VALVE FAIL OPEN" MSG24529A.

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