Robinson R44 Astro Agricultural Spraying Accident at Ntomeni Sugar Estate (ZS-RHX)

Accident Overview and Flight History On 7 September 2013, at 0645Z, a Robinson R44 Astro helicopter, registration ZS-RHX, was conducting an agricultural spraying operation at the Ntomeni Sugar Estate in KwaZulu-Natal, South Africa. The aircraft was operated by Vortex Aviation and piloted by a 36-year-old commercial pilot. The flight was conducted under visual meteorological conditions, with the pilot taking off from and intending to land at the Ntomeni Sugar Estate. During the first run of the spraying detail, the pilot observed electrical power lines across his intended flight path. Despite having conducted a prior aerial inspection of the field, the pilot realized the power lines were angled toward him. He immediately took evasive action by climbing and turning right to avoid a collision. This maneuver caused a significant decay in airspeed and main rotor revolutions per minute (rpm). ## Forced Landing and Damage In an attempt to restore airspeed and rotor rpm, the pilot flew down a valley. However, due to the slope of the valley and the helicopter's proximity to the ground, he was unable to regain the necessary airspeed and rpm. The pilot then decided to perform a forced landing. A hard landing on sloping terrain followed, causing the helicopter to roll over onto its right side. The helicopter and its spraying system were substantially damaged. The pilot was not injured in the accident. The accident was considered survivable due to the low kinetic forces associated with the impact and the pilot wearing his safety harness. There was no pre- or post-impact fire. ## Aircraft and Personnel Information The aircraft, a Robinson R44 Astro manufactured in 1996, had a serial number of 0295 and 3,129.9 total airframe hours at the time of the accident. The last mandatory periodic inspection (MPI) was certified on 23 August 2013. The pilot held a valid commercial license with a type endorsement for the helicopter and had 5,383.3 total flying hours, including 957.4 hours on type. ## Analysis and Probable Cause The investigation found that the pilot was appropriately licensed and qualified for the flight. However, the pilot failed to perform a proper weight and balance calculation prior to the flight. Weight calculations indicated the helicopter was operated at 2,449 pounds, which was 49 pounds more than the certified maximum take-off weight of 2,400 pounds. The probable cause of the accident was an unsuccessful forced landing. A contributing factor was the pilot's failure to keep a proper lookout for obstacles in the flight path. The evasive action taken to avoid the power lines placed the aircraft in a dangerous position with insufficient airspeed and low rotor rpm, ultimately forcing the pilot to execute the forced landing.