What happened
On the morning of 19 November 2025, a Regional Express Saab 340 departed Townsville for Hughenden. The pilot in command programmed the flight management system (FMS) using external power before engine start. After take-off, when the autopilot was engaged, the aircraft immediately attempted to turn left, deviating from the CATEY ONE standard instrument departure (SID) track.
The first officer observed that the FMS indicated CATEY as the first active waypoint rather than AGSIR, which should have been the first SID waypoint. Although the SID waypoints were present in the flight plan, they appeared visually distinct, possibly 'greyed out'. Attempts to re-sequence the route using the 'Direct-To' function failed because the system would not accept the selected SID waypoints.
The investigation
The ATSB examined the operator's procedures and the FMS manufacturer's potential failure scenarios. No fault was found in the operator's FMS database, and the manufacturer could not replicate the issue using their training simulator.
Analysis suggested that if the SID entry was initiated but not fully completed before the FMS was powered down for engine start, the procedure might have remained displayed but unlinked to active guidance. This would explain the visual discrepancy noted by the crew. However, without access to the FMS download or cockpit voice recorder, the exact reason for the invalid data appearance could not be determined.
Findings
The investigation identified a procedural gap in Regional Express's operations. When programming the FMS before engine start using external power, existing procedures did not require the crew to verify the programmed flight plan after engine start and before take-off. This increased the risk of departing with a data error undetected.
Additionally, the pilot in command misunderstood the operator's intended check of the first waypoint. They interpreted it as the first waypoint of the company flight plan rather than the first waypoint after take-off. While it could not be determined if this misunderstanding directly contributed to the incident, it increased the risk of a data entry error going unnoticed.