History of Flight
On 28 November 2007 at 1500Z, a Bell 206L-4 helicopter, registration ZS-RHZ, operated by King Air Services Partnership, was conducting a training flight with an instructor and a student pilot. The flight departed from Lanseria Aerodrome for a local type conversion flight. During an autorotation approach for landing from an easterly direction, the instructor reported that the helicopter nose was slightly high upon completion of the flare. This resulted in a firm touchdown of the rear skids. Due to low main rotor RPM, the rotor blades flapped downward and struck the left-hand vertical fin stabiliser, causing it to separate from the horizontal stabiliser. The helicopter then skidded for less than approximately one metre before coming to a stop. The weather at the time was surface wind 090° at 12 knots, visibility good, temperature 20°C, overcast cloud cover with a base of 2,000 feet, and dew point 14°C. The incident occurred in daylight conditions in an open field north of Lanseria Aerodrome (GPS position: South 25°47,028 East 027°54,332).
Aircraft Damage
The aircraft sustained damage on the left-hand vertical fin stabiliser and on the middle of the side in the centre of the tail boom due to the impact by the main rotor blades.
Injuries
No injuries were sustained.
Probable Cause
The probable cause of the incident was that the instructor allowed the main rotor’s RPM to decay to below minimum, which resulted in a hard landing in which the main rotor blades impacted both the vertical fin stabiliser and the tail boom.