# SDR 2026FA0000795

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 7, 2026
- Submitted: September 30, 2026
- Operation: General aviation
- Aircraft: [N1416T](https://openairdocs.org/aircraft/N1416T), registered now
- Make and model: Piper PA-28-140
- Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (OpenAirDocs)
- Aircraft serial: 287225507
- Engine: Lyc O320E2D
- System (JASC): [7414 · Magneto/Distributor](https://openairdocs.org/jasc/7414)
- Part: Magneto
- Part number: 4N0421009
- Condition: Faulted
- Location: Rt Engine
- Stage of operation: NR
- How discovered: O
- Nature of condition: R
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/2026FA0000795

## Discrepancy

DURING FLIGHT, THE ENGINE EXPERIENCED A SMOOTH PARTIAL LOSS OF POWER WITH AN RPM DECREASE OF APPROX 200–400 RPM.  DISCONTINUED THE FLIGHT & MADE AN EMERGENCY LANDING AT AN AIRPORT OTHER THAN THE ACFT’S HOME AIRPORT. THE MAGNETO HAD APPROX 115 HRS OF SERVICE & WAS CONFIGURED FOR 25° FIXED TIMING VIA THE DIP SWITCHES. DURING TROUBLESHOOTING, THE MAGNETO LED INDICATED 25° VARIABLE RATHER THAN 25° FIXED.  THIS CAUSED A DETONATION EVENT IN THE ENGINE. CONTACTED MANUFACTURER & INSTRUCTED TO RESET THE UNIT. AFTER 3 SEPARATE RESETS, THE LED CONTINUED TO INDICATE 25° VARIABLE. DURING THE EVENT, NR 4 CHT INCREASED SIGNIFICANTLY.  INSPECTION & BORESCOPE EXAM, SHOWED EVIDENCE CONSISTENT WITH ABNORMAL COMBUSTION/DETONATION. NR 4 LEAKDOWN WAS APPROX 58/80. THE CAUSE OF THE TIMING ANOMALY AND ITS RELATIONSHIP TO THE ENGINE CONDITION HAS NOT YET BEEN CONCLUSIVELY DETERMINED. I AM AN A&P/IA AND PERFORMED THE TROUBLESHOOTING AND INSPECTION.

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