# SDR ASAA2023110246021

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 2, 2023
- Submitted: November 7, 2023
- Operation: Air carrier
- Aircraft: [N494AS](https://openairdocs.org/aircraft/N494AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41729
- Aircraft time: 28,606 hours, 8,710 cycles
- System (JASC): [4940 · APU Start/Ignition System](https://openairdocs.org/jasc/4940)
- Part: Unknown
- Part number: UNKNOWN
- Condition: Unknown
- Location: Unknown
- Stage of operation: CR
- How discovered: V
- Nature of condition: J
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2023110246021

## Discrepancy

FAULT LIGHT ILLUMINATED DURING APU START ATTEMPT AT FL340 DURING FIRST AND SECOND TRY. SUCCESSFUL CSS ACCOMPLISHED AFTER FAULT LIGHT EXTINGUISHED AT FL300. GROUNDED - YES. PER SEAMC DUE TO APU BEING DEFERRED FOR THIS ISSUE, CSS IS CONSIDERED UNSATIFACTORY. APU TO REMAIN ON 49-99A. SEAMC AUTHORIZED.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.