# SDR UIEA2026072300640

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 23, 2026
- Submitted: July 23, 2026
- Operation: Air carrier
- Aircraft: [N418MC](https://openairdocs.org/aircraft/N418MC), registered now
- Make and model: Boeing 747-47UF
- Registry model: [Boeing 747-47UF](https://openairdocs.org/model/boeing-747-47uf) (OpenAirDocs)
- Aircraft serial: 32840
- Aircraft time: 94,142 hours, 15,402 cycles
- System (JASC): [4990 · APU Oil System](https://openairdocs.org/jasc/4990)
- Part: Apu
- Part number: 28B26313B
- Part serial: 891C
- Condition: Odor
- Location: Zone 100
- Stage of operation: TX
- How discovered: O
- Nature of condition: K, B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/UIEA2026072300640

## Discrepancy

BACK TO BLOCK DUE TO EICAS MESSAGE SMOKE CREW REST AND UNUSUAL SCENT DETECTED IN UPPER DECK.  PERFORM FIRE TEST, NO SMOKE PRESENT IN CABIN. OIL SCENT COMING FROM APU. SUSPECT APU BEARING OIL LEAK ENTERING CABIN. REMOVED AND REPLACED APU IAW ATLAS WORK CARD 49-099-00-01. OPS CHK OK.

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