# SDR 0004556622

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 20, 2000
- Submitted: January 3, 2001
- Operation: Air carrier
- Aircraft: N622US
- Make and model: Boeing 747251B
- Aircraft serial: 21704
- Aircraft time: 83,208 hours, 13,820 cycles
- System (JASC): [5412 · Nacelle/Pylon, Bulkhead/Firewall](https://openairdocs.org/jasc/5412)
- Part: Chord
- Condition: Cracked
- 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/0004556622

## Discrepancy

During "L" check found crack on the upper chord at the rear engine mount bulkhead NAC station 222 number one pylon. Repaired per EA 66-180413.

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