What happened
On August 11, 2002, a Robinson R-22 helicopter, registration ZS-RHF, was preparing for a private flight from Lanseria Airport to Kroonstad, with a planned subsequent stop in Bultfontein. The flight was carrying two occupants. Before departure, the crew added 43 liters of fuel, leaving the main tank at three-quarters capacity and the auxiliary tank at one-quarter.
During the initial attempt to take off, the pilot performed a power check that resulted in the aircraft entering a hover, during which a low rotor RPM audio warning was triggered. The pilot subsequently landed the aircraft back on the ground. A second attempt to become airborne was made, but the low rotor RPM warning sounded once again. During this second attempt, the aircraft drifted sideways, leading to a hard landing. The skid gear struck an embankment adjacent to the taxiway, causing the helicopter to roll onto its left side. No injuries were reported to the pilot or the passenger.
The investigation
The investigation focused on the flight conditions and the mechanical warnings received during the takeoff sequence. Investigators examined the fuel load and the aircraft's weight configuration relative to its performance capabilities. The inquiry established that the aircraft's weight was a critical factor in the inability to maintain stable flight parameters during the power check and subsequent takeoff attempts.