Accident Overview
On a mustering operation at Mulgathing Station in South Australia, a Cessna Aircraft Corporation 172N, registered VH-SQO, was observed diving toward a group of sheep. After pulling out of the dive, the aircraft rolled to the left, descended, and impacted terrain. Examination of the wreckage revealed no defects or anomalies with recovered components that might have contributed to the accident. The propeller damage indicated a power-on impact. There was no evidence of adverse weather or fuel issues. Pilot incapacitation was deemed unlikely given the pilot's age, medical history, reported health prior to the flight, and toxicological results.
Loss of Control
Witnesses reported that the aircraft descended from approximately 150–200 ft to about 50 ft above the ground, then pitched up at a steep nose-up attitude of about 60° to an estimated 250–300 ft with no observed change in engine power. The aircraft then banked left and descended to the ground. The witness noted that the climb angle was steeper than the descent angle, and the exit height exceeded the entry height. These observations were consistent with a loss of control during the exit of the dive. The steep climb-out likely caused a rapid airspeed decay and increase in angle of attack, making the aircraft susceptible to a power-on stall and subsequent spin. On-site examination showed the aircraft impacted the ground in about a 70° nose-down attitude with no forward momentum; both the engine and tail sections were deflected to the right. These findings were consistent with a stall and left spin. According to the Pilot's Operating Handbook, the stall and spin occurred at a height from which recovery was not possible, resulting in the impact.
Pilot Qualifications
Aerial mustering with an aeroplane requires both a low-level rating and an aerial mustering endorsement. The pilot held a low-level rating but did not possess the aerial mustering endorsement. During the pilot's time at Mulgathing Station, they were observed on several occasions diving toward sheep in an attempt to move them—a maneuver considered to be aerial mustering. On the day of the accident, the pilot declined assistance from a colleague on a motorbike, stating an intention to move the sheep with the aircraft. The lack of the additional training and experience associated with the aerial mustering endorsement likely left the pilot ill-equipped to manage the challenges of mustering sheep, increasing the risk of a loss of control at low level.
Job Application and Role
The pilot applied for and was hired for a position described as a pilot/station hand. The job advertisement stated that the main flying duties would be 'aerial stock mustering.' However, the qualifications listed for the role did not include an aerial mustering endorsement, and the pilot did not hold one. The specifications were consistent with the operator's intention for aerial spotting, requiring only a low-level rating. Despite the advertisement's description, the pilot was observed mustering sheep using maneuvers outside the scope of their qualifications and the operator's intentions. Several staff at the station, including the station manager, witnessed these actions, but none reported being aware that the pilot was not qualified to perform aerial mustering.
Seatbelt Usage
On-site inspection found that the upper torso restraint was stowed in the roof line, indicating it was not used by the pilot. At the time of the accident, only the lap belt was required to be used. However, the aircraft was fitted with an over-the-shoulder sash belt, the benefits of which were not realized in this instance.