# SDR 99ZZZX4370

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 29, 1999
- Submitted: March 26, 2000
- Operation: General aviation
- Aircraft: N602FF
- Make and model: Boeing 747124
- Aircraft serial: 19734
- System (JASC): [5711 · Wing Spar](https://openairdocs.org/jasc/5711)
- Part: Spar
- Condition: Corroded
- Location: Ws 444-520
- Stage of operation: IN
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/99ZZZX4370

## Discrepancy

DURING MAINTENANCE C-CHECK, BEJ FOUND SEVERE CORROSION ON THE REAR SURFACE OF VERTICAL LEG OF THE LEFT WING REAR SPAR UPPER CHORD AT WS 550, WS 520, AND WS 444.

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