# SDR TWAA0102902

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 9, 2001
- Submitted: February 14, 2001
- Operation: Air carrier
- Aircraft: N9401W
- Make and model: Doug DC-9-83
- Registry model: [Doug DC-9-83](https://openairdocs.org/model/douglas-dc-9-83) (OpenAirDocs)
- Aircraft serial: 53137
- Aircraft time: 25,345 hours, 12,172 cycles
- System (JASC): [5531 · Vertical Stabilizer, Spar/Rib](https://openairdocs.org/jasc/5531)
- Part: Rib
- Condition: Cracked
- Location: Dorsal Fin
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/TWAA0102902

## Discrepancy

DURING CHECK-C MAINT NUMBER 3 AND 4 DORSAL FIN RIBS, FROM UPPER EDGE ON LT SIDE, WERE CRACKED.  ROUTED AND RADIUSED END OF RIB. INSTALLED REPLACEMENT FILLER ON NUMBER 3 AND 4.  INSTALLED 2024-T3 0.050 DOUBLER PICKING UP MINIMUM 3 ROWS OF FASTENERS BEYOND CRACK PER 55-30-102.

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