What happened
During the final stages of a mustering operation, a pilot was attempting to move the last remaining animal into a holding paddock. As the animal approached a gate, it suddenly stopped, prompting the pilot to flare the helicopter while flying at a low altitude. At the time, the aircraft was operating with a quartering tailwind. This maneuver caused the aircraft to descend, leading to the tail rotor making contact with the ground. The impact resulted in a loss of yaw control and caused the right skid to hit the terrain, which subsequently led to the aircraft rolling over.
The investigation
The investigation focused on the pilot's actions and the environmental conditions during the maneuver. It was determined that the pilot's attention was divided between managing the aircraft and ensuring the animal passed through the gate. This focus on the livestock likely reduced the pilot's awareness of the aircraft's height and the impact of the wind on performance.
While flying approximately 6 ft above the ground and roughly 4 m behind the animal, the pilot performed an instinctive flare. Due to the tailwind, the pilot likely perceived a higher airspeed than was actually present. The flare, combined with a lack of anticipated power, caused the aircraft to lose altitude and brought the tail rotor closer to the terrain. There was insufficient time to apply the necessary power to arrest the descent before the strike occurred.
Findings
- The pilot's focus on moving the stock led to flying in very close proximity to both the ground and the animal.
- The pilot flared the aircraft in response to the animal's movement, which triggered the descent.
- The combination of the tailwind and the low-level flare caused the tail rotor to strike the ground.
- The impact caused an uncontrollable yaw to the right.
Safety message
Recent emergency training, specifically a proficiency check conducted less than two months prior that included tail rotor failure simulations, assisted the pilot in managing the subsequent loss of control. The pilot's use of correct technique—reducing throttle to decrease torque and increasing collective to manage the descent—likely prevented more serious injuries.