What happened
On the flight from Canberra, Australian Capital Territory, to Armle, New South Wales, the Cirrus aircraft, registration VH-MSF, was climbing toward a planned cruising altitude of 10,000 ft. Approximately 12 minutes after departure, the aircraft's flight path became unstable, characterized by fluctuations in altitude, airspeed, and heading. During this phase, witnesses reported hearing engine surging sounds while the aircraft was obscured by clouds.
As the aircraft climbed, it experienced two instances where the airspeed dropped near stall speeds. While the flight data suggested a possible attempt at recovery, the aircraft subsequently experienced a rapid loss of airspeed and altitude at approximately 9,946 ft. This led to an aerodynamic stall and a departure from controlled flight. The aircraft entered a rapid descent, reaching a rate of about 13,000 ft/min, and likely entered a spin before impacting the terrain. The impact resulted in 4 fatalities and a post-impact fire destroyed the airframe.
The investigation
The ATSB examined flight track data, wreckage, and witness accounts to determine the sequence of events. Investigators noted that the aircraft's flight path changed from a steady state to irregular movements around 8,300 ft, suggesting the pilot may have transitioned from autopilot to manual flight, potentially to avoid turbulence or clouds.
While the pilot's operating handbook (POH) provides specific procedures for stall recovery—such as reducing back pressure and increasing power—the flight data showed no evidence of such a recovery. Furthermore, although the Cirrus Airframe Parachute System (CAPS) was available, wreckage inspection revealed the parachute was not deployed in flight, but rather triggered by the force of the ground impact. The investigation also found that the required engine shutdown procedure prior to CAPS deployment was not performed.
Findings
- The primary cause of the loss of control was an aerodynamic stall occurring as the climb rate increased and airspeed decreased near 10,000 ft.
- The aircraft likely entered a spin following the stall, which was not recovered through manual flight controls.
- The Cirrus Airframe Parachute System (CAPS) was not activated by the pilot during the descent.
- The flight was planned through forecast moderate icing conditions, despite the aircraft being prohibited from operating in such environments. While the impact of icing on performance could not be definitively proven, the encounter was highly probable.