Accident Sequence
During the final stages of a mustering operation, four out of five animals had been returned to the yard. The pilot became highly motivated to complete the task and focused increasingly on moving the last remaining animal through to the holding paddock while flying close to the ground. When the animal baulked at a gate, the pilot estimated the helicopter was moving forward about 4 meters behind the animal at approximately 6 feet above ground level.
To prevent the animal from escaping, the pilot flared the helicopter while low to the ground with a quartering tailwind. During the flare, the helicopter descended, resulting in the tail rotor impacting the ground. The pilot lost yaw control, and the right skid contacted the ground, causing the helicopter to roll over.
Divided Attention and Environmental Factors
The pilot's attention was divided between managing the helicopter and focusing on the last animal. This likely reduced awareness of the helicopter's proximity to the animal, the ground, and the effect of the prevailing wind on helicopter performance. The helicopter's close proximity to the animal and forward momentum limited the pilot's reaction time and options for recovery.
Pilot's Reaction
The pilot likely judged airspeed by visual reference to ground features, and the tailwind may have given a sensation of higher airspeed. With limited time to respond, the pilot flared the aircraft as an automatic reaction to the animal's movement. The pilot did not anticipate the additional power required during the flare, leading to descent. The change in pitch attitude lowered the tail rotor closer to the ground. With minimal clearance, there was insufficient opportunity to apply additional power to climb or arrest the descent before tail rotor ground impact.
Response to Ground Impact
After the tail rotor struck terrain, the helicopter began to rapidly rotate to the right. The pilot assessed a tail rotor failure and reduced throttle to decrease torque, then increased collective prior to impact to manage the rate of descent. The operator had conducted a proficiency check flight with the pilot less than 2 months prior, which included tail rotor failure simulations. The recent emergency training likely helped the pilot react with the correct technique before the helicopter became uncontrollable.