# SDR SWAA2024010335622

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 27, 2023
- Submitted: January 3, 2024
- Operation: Air carrier
- Aircraft: N7851A
- Make and model: Boeing 737-7Q8
- Registry model: [Boeing 737-7Q8](https://openairdocs.org/model/boeing-737-7q8) (OpenAirDocs)
- Aircraft serial: 28240
- Aircraft time: 63,802 hours, 42,067 cycles
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Actuator
- Part number: UNKNOWN
- Condition: Faulty
- Location: Zn 100 Fus Lower
- Stage of operation: CL
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SWAA2024010335622

## Discrepancy

AUTOPILOT WOULD NOT ENGAGE; STAB OUT OF TRIM LIGHT ILLUMINATED MOMENTARILY. PLANE NOSED OVER SLIGHTLY; AUTOPILOT CONTINUED TO DISENGAGE AND WOULD NOT REMAIN ENGAGED. FLIGHT CONTROLS WERE LESS RESPONSIVE IN ROLL THAN USUAL. AUTOPILOT IS FAULTING THE LVDT ON THE ELEVATOR AUTOPILOT ACTUATOR.<[01] PERFORMED FIM 27-11 TASK 808; VISUALLY INSPECTED AILERON CABLES ABSA AND ABSB CABLES FOR BLOCKAGE/DAMAGE. NO DEFECTS NOTED TO CABLES. REF AMM 27-11-00 STEP I; ABSA LH WAS AT 175; ABSB LH 176. ABSA RH 180; ABSB RH 180. ALL CABLE TENSIONS WITHIN LIMITS. PERFORMED AILERON TRAVEL TEST REF AMM 27-11-00; AILERON DEFLECTION NORMAL AND WITHIN LIMITS.;[02] PER FIM 27-11 TASK 808; CONFORMATION AILERON OPS NORMAL. NO FAULTS FOUND AT THIS TIME.;[03] R&R 'B' AUTOPILOT ELEVATOR ACTUATOR IAW AMM 22-11-26

---
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.