# SDR UALA2013012100366

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 18, 2013
- Submitted: February 8, 2013
- Operation: Air carrier
- Aircraft: [N197UA](https://openairdocs.org/aircraft/N197UA), registered now
- Make and model: Boeing 747422
- Aircraft serial: 26901
- Aircraft time: 62,506 hours, 7,340 cycles
- Engine: Pwa PW4056
- System (JASC): [3610 · Pneumatic Distribution System](https://openairdocs.org/jasc/3610)
- Part: B-Nut
- Condition: Loose
- Location: Valve
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UALA2013012100366

## Discrepancy

BLEED FAMV ENGINE 4 CAME ON AT LVL OFF AT FL 330.  FOUND B-NUT LEAKING AT FAN AIR VALVE MUSCLE AIR CONNECTION.  REPLACED MUSCLE AIR LINE AND TEMP SENSE LINE.  BACKED OFF B-NUT AND SAW METALLIC PARTICLES.  STEM FITTING LOOKED OK, LOOSENED ADJ LINE STAND OFFS. HAND STARTED B-NUT, HALF WAY DOWN STARTED TO BIND.  REPLACED MUSCLE AIR LINE AND TEMP SENSE LINE.

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