Incident
On 5 May 2006, a Robinson R22 BETA helicopter (registration ZS-RAO) departed from Steenbokpan farm in Vaalwater near Thabazimbi for a short flight to Umzimpele farm, also in Vaalwater. The pilot, accompanied by a passenger, was conducting a private operation. The pilot held a valid private pilot license with 317.5 total flying hours, including 275.1 hours on type. The flight was conducted under visual meteorological conditions with good visibility, temperature 19°C, and calm northeast wind.
During the approach for landing on an identified open field at an indicated airspeed of approximately 50 knots, the pilot required more power and applied it. At that moment, the engine suffered a sudden loss of power. The pilot immediately lowered the collective pitch lever to attain forward speed, but tall trees in the area provided insufficient clearance. The helicopter impacted the trees and rolled onto its port side. The main rotor blades were substantially damaged upon impact with the trees, and the tail rotor blades failed on impact. The pilot did not sustain any injuries; the passenger suffered an injury to his wrist.
Investigation
The last Mandatory Periodic Inspection (MPI) was certified on 13 March 2006 at 3056.2 airframe hours. The aircraft had been operated for 100.6 hours since that MPI. The Aircraft Maintenance Organisation (Nr. 846) responsible for the maintenance was audited within the previous two years with no major findings recorded. The helicopter was recovered to an approved maintenance organization for further investigation. It was tied down in the same configuration as recovered, and ground run tests were performed. The engine operated smoothly without any abnormalities observed.
Probable Cause
The probable cause of the accident was determined to be the helicopter colliding with high trees during a landing in an open field on a private farm. A contributory factor was an error in judgment by the pilot in command with regard to the safe clearance of the trees while landing.