What happened
On 18 September 2005, a Replica Fokker D-VII, registration ZS-VSY, was conducting a private flight from Kitty Hawk Aerodrome to Rand Aerodrome. The aircraft had recently been acquired by new owners and was fully fueled with 25 litres of fuel for the short trip.
While on final approach to Runway 11 at Rand Aerodrome, the pilot encountered a sudden loss of engine power. Realizing the aircraft could not glide to the remaining runway, the pilot attempted an emergency landing on a tarred road intersecting the flight path. During this maneuver, the aircraft's main landing gear struck the corrugated roof of a self-storage facility in the Germiston area. The impact caused the aircraft to strike a palisade fence before coming to a halt. There were no injuries to the pilot, though the aircraft sustained substantial damage.
The investigation
SACAA AIID investigators examined the mechanical state of the aircraft and the engine's performance. The investigation noted that the aircraft's last annual inspection had been completed on 1 July 2005, with only 0.8 flight hours accumulated since that certification. The maintenance was performed by an authorized person rated for this specific type of aircraft.
Findings
The investigation established that the engine failure was caused by the engine RPM being set too low. Because the Rotax two-stroke engine's idle was set at an insufficient level, the inertia of the propeller prevented a rapid response when the pilot moved the throttle forward to increase power. This lack of responsiveness led to a sudden, unannounced engine stoppage during the pilot's attempt to manage the power settings.