# SDR 2017FA0000398

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: August 9, 2017
- Submitted: August 9, 2017
- Operation: General aviation
- Aircraft: [N4770L](https://openairdocs.org/aircraft/N4770L), registered now
- Make and model: Piper PA 28-180
- Registry model: [Piper PA 28-180](https://openairdocs.org/model/piper-anderson-pa-28-180) (OpenAirDocs)
- Aircraft serial: 284102
- System (JASC): [5330 · Fuselage Main, Plate/Skin](https://openairdocs.org/jasc/5330)
- Part: Skin
- Condition: Cracked
- Location: Belly
- 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/2017FA0000398

## Discrepancy

DURING AN ANNUAL INSPECTION,  A 4.5 INCH CRACK WAS FOUND IN THE SKIN AT THE AFT EDGE OF THE BOTTOM CHANNEL STIFFENER, REAR SPAR LOCATION.  STOP DRILLED THE CRACK AND INSTALLED A DOUBLER.   AIRFRAME HAS 6261 HRS AND WAS USED FOR FLIGHT TRAINING.  REPETITIVE STRESS LOADING AND FLEXING IN THAT AREA OF STRESS CONCENTRATION MOST LIKELY CAUSED THE SKIN TO CRACK FROM FATIGUE.

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