# SDR ASAA2019090830668

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 8, 2019
- Submitted: September 16, 2019
- Operation: Air carrier
- Aircraft: [N440AS](https://openairdocs.org/aircraft/N440AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 41705
- Aircraft time: 23,336 hours, 7,591 cycles
- System (JASC): [2420 · AC Generation System](https://openairdocs.org/jasc/2420)
- Part: Unknown
- Condition: Malfunctioned
- Location: Electrical Sys
- Stage of operation: NR
- How discovered: O
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2019090830668

## Discrepancy

APU GEN BUSES WILL NOT COME ON LINE WHEN SELECTED. GROUNDED - YES. PERFORMED OPS TEST FOR THE AC GENERATION AND CONTROL SYSTEM IAW AMM 24-24-00-700-803 STEPS 2A THROUGH 2E(Z)(4). BOTH APU BUS TIES OPERATE NORMALLY. NO FAULTS NOTED. NO CHANGES TO AIRCRAFT CONFIGURATION. PLACARDS REMOVED. SEAMC NOTIFIED.

---
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.