# SDR IPXA2022103119573

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 28, 2022
- Submitted: October 31, 2022
- Operation: Air carrier
- Aircraft: [N573UP](https://openairdocs.org/aircraft/N573UP), registered now
- Make and model: Boeing 747-44AF
- Registry model: [Boeing 747-44AF](https://openairdocs.org/model/boeing-747-44af) (OpenAirDocs)
- Aircraft serial: 35662
- Aircraft time: 53,191 hours, 8,337 cycles
- System (JASC): [2612 · Fire Detection](https://openairdocs.org/jasc/2612)
- Part: Fire Warning
- Condition: Illuminated
- Location: Apu Bay
- Stage of operation: CR
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/IPXA2022103119573

## Discrepancy

APU FIRE SWITCH LIGHT IN SWITCH BEGAN FLICKERING EN ROUTE SHORTLY AFTER EICAS MSSG APU FIRE BEGAN APPEARING ON & OFF RAPIDLY THEN APU FIRE BELL WENT OFF. LINKED TO L8ZJ & L8Z8.  APU FIRE BOTTLE REPLACED.

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