# SDR CA030717001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 15, 2003
- Submitted: August 18, 2003
- Operation: General aviation
- Make and model: Beech C90A
- Registry model: [Beech C90A](https://openairdocs.org/model/beech-c90a) (OpenAirDocs)
- Aircraft time: 3,060 hours
- Engine: Pwa PT6A21
- System (JASC): [3710 · Vacuum Distribution System](https://openairdocs.org/jasc/3710)
- Part: Line
- Part number: 1013202661
- Condition: Chafed
- Location: Vacuum Regulator
- Stage of operation: NR
- How discovered: O
- Nature of condition: D
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CA030717001

## Discrepancy

(CAN) DURING A MAINTENANCE GROUND RUN, AND FOLLOWING THE START OF THE RT ENGINE, A HISSING SOUND WAS NOTICED EMITTING FROM BEHIND THE INSTRUMENT PANEL. AFTER FURTHER INVESTIGATION IF WAS FOUND THAT THE INSTRUMENT AIR TUBE HAD BEEN CHAFING ON THE UPPER CORNER OF THE RADIO RACK. THE TUBE IS USED TO JOIN THE VACUUM REGULATOR TO THE LT SIDE OF THE FORWARD BULKHEAD TO THE MANIFOLD LOCATED IN THE COCKPIT BEHIND THE INSTRUMENT PANEL ON THE RT SIDE.

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