What happened
On December 3, 2002, a PIPER PA22-150, registration ZS-NHK, was conducting a conversion training flight at Lanseria Aerodrome. The flight, operated by a flight training school, involved an instructor demonstrating maneuvers to a student pilot. Following several successful touch-and-go landings on Runway 06R, the instructor attempted a full-stop landing. During the flare, the throttle was closed; however, upon touchdown, a pronounced shimmy developed in the tailwheel.
As the aircraft decelerated, it began to veer toward the right side of the runway. Despite the instructor's attempts to maintain the centerline using the brakes, rudder, and tailwheel steering, the aircraft drifted off the paved surface and onto the grass. The excursion resulted in the collapse of the left-hand main landing gear. There were no injuries and no fatalities resulting from the incident.
The investigation
SACAA AIID examined the circumstances surrounding the loss of control. The investigation confirmed that the flight was authorized and that the instructor held a valid Commercial pilot's license with an Instructor Grade II rating. Meteorological data at the time of the accident indicated fine weather with a temperature of 18°C and light, variable winds. The investigation focused on the mechanical behavior of the tailwheel assembly and the pilot's ability to maintain directional stability during the landing roll.