What happened
A non-revenue flight operating under instrument flight rules, carrying two pilots and four passengers, was en route to Truckel, California. During the descent, air traffic control assigned the crew an RNAV approach for runway 20. However, the pilot flying and the pilot monitoring determined that the runway length was insufficient for the aircraft's landing weight. Rather than requesting a straight-in approach to the longer runway 11, the crew opted for a circle-to-land approach to runway 20, which would eventually transition to runway 11.
The crew failed to brief the new approach as required by descent checklists. During the maneuver, the aircraft maintained excessive airspeed, which the pilot monitoring noted but the pilot flying did not address. While attempting to establish a downwind leg parallel to runway 11, the pilot monitoring instructed an early roll-out, causing the aircraft to fly a course that required an unnaturally tight turning radius. Additionally, the pilot monitoring deployed flaps to 45 degrees, exceeding the standard 30-degree setting for that leg.
As the aircraft transitioned to the base leg, the pilot monitoring repeatedly requested control of the aircraft, though no formal transfer of control was verbalized. The aircraft was noted to be too high, leading to the deployment of flight spoilers to increase the sink rate. Shortly after, the aircraft experienced a stall, indicated by the activation of the stick shaker and stick pusher. The aircraft entered a rapid left roll and impacted the terrain, resulting in six fatalities.
Findings
- The crew failed to perform a required briefing for the modified approach.
- Improperly executed maneuvering and an early roll-out created a flight path requiring an unsustainable turning radius.
- The aircraft was operating at an airspeed significantly above the calculated landing reference speed.
- There was a lack of clear communication and a failure to formalize a transfer of control between the pilots during the critical phase of the approach.