# SDR 2018FA0000147

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 18, 2018
- Submitted: April 18, 2018
- Operation: General aviation
- Aircraft: [N4075R](https://openairdocs.org/aircraft/N4075R), registered now
- Make and model: Piper PA-32-300
- Registry model: [Piper PA-32-300](https://openairdocs.org/model/piper-pa-32-300) (OpenAirDocs)
- Aircraft serial: 3240387
- Engine: Lyc IO540K1A5
- Engine time: 8,045 hours
- System (JASC): [7414 · Magneto/Distributor](https://openairdocs.org/jasc/7414)
- Part: Rivet
- Condition: Sheared
- Location: Impulse Coupling
- Part time: 160 hours
- Component: Magneto, Slick, 6351
- Component part number: 6351
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2018FA0000147

## Discrepancy

LEFT MAGNETO IMPULSE COUPLING FAILED. . AD 99-04-04 APPLIES TO THIS MAGNETO ENGINE COMBINATION. INTERVAL FOR REPETITIVE INSPECTIONS IS 250 HRS. MAGNETO HAD BEEN RECENTLY REPLACED WITH A REBUILT UNIT AND  HAS A NEW IMPULSE COUPLING.  THE IMPULSE COUPLING SHEARED INTERNAL RIVETS CAUSING MAGNETO TO BIND WHICH CAUSED TWO TEETH TO BREAK OFF OF THE DRIVE GEAR AND DAMAGED ACCESSORIES DRIVE SYSTEM.

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