# SDR ASAA2018100626413

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 6, 2018
- Submitted: October 9, 2018
- Operation: Air carrier
- Aircraft: [N590AS](https://openairdocs.org/aircraft/N590AS), registered now
- Make and model: Boeing 737890
- Aircraft serial: 35687
- Aircraft time: 40,841 hours, 12,371 cycles
- System (JASC): [4960 · APU Controls](https://openairdocs.org/jasc/4960)
- Part: Sensor
- Part number: 38762231
- Condition: Failed
- Location: Apu
- Stage of operation: CR
- How discovered: O
- Nature of condition: N
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2018100626413

## Discrepancy

FAULT LIGHT ILLUMINATED ON APU CSS AT FL380. GROUNDED - YES. CHECKED MAG PLUG PER FIM 49-60 TASK 817 STEP 4. NO DEFECTS NOTED. REPLACED SPEED SENSOR PER FIM 49-60 TASK 817 STEP 8 AND AMM 49-61-21. OPS CK GOOD, LK CK GOOD. NO FAULTS FOUND. STARTED APU SEVERAL TIMES WITH NO DEFECTS NOTED. ETOPS GROUND VERIFICATION C/W. THIS CLEARS MEL 49-1B.

---
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.