The ATSB is investigating a control issue involving a Raytheon Aircraft Company C90A, registered VH-JEO, at 180 km north-east of Kalgoorlie-Boulder Airport, Western Australia, on 25 January 2024.
During cruise while in instrument meteorological conditions (IMC), the horizontal situation indicator (HSI) failed, resulting in a continuous and uncommanded right turn. The pilot disengaged the autopilot and hand flew the aircraft resulting in minor controllability issues. The aircraft was returned to Kalgoorlie and the post-flight engineering inspection confirmed a failed left HSI remote gyroscope.
The evidence collection phase of the investigation will involve interviewing the pilot, reviewing recorded data, and the collection of other relevant information.
A final report will be released at the conclusion of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties, so that appropriate safety action can be taken.