Accident Overview
On 12 September 2002, a Beech 76 aircraft registered as ZS-KHG was involved in an accident near Wonderboom, South Africa. The aircraft was conducting a twin conversion training flight with a student pilot and an instructor on board. The flight departed from Wonderboom Airport (FAWB) at 1013Z for the Pretoria General Flying Training Area No. 2.
Pre-flight Events
Before the flight, the student pilot experienced difficulty starting the left-hand engine. Assistance was obtained from a nearby aircraft maintenance organization. The dual magneto of the left engine was removed and bench tested, found to operate normally, and reinstalled. The engine then started successfully. The aircraft was refueled with 252 liters of Avgas 100LL.
In-flight Engine Shutdown and Restart Attempts
After takeoff, the aircraft climbed to 8000 feet. The instructor commenced single engine performance demonstrations by pulling the mixture lever of the left-hand engine to the idle/cut-off position. The student pilot secured the engine per procedures, which the instructor deemed satisfactory. Approximately two minutes later, the engine restart procedure was initiated. After several unsuccessful attempts by both the student and the instructor, the left engine could not be restarted. The aircraft continued descending on the right-hand engine.
Emergency and Forced Landing
The instructor turned back toward Wonderboom and was positioned at the northern boundary of the Roodeplaat dam. Unable to maintain altitude, an emergency was declared and a forced landing on a dirt road was carried out approximately 7 nautical miles northeast of Wonderboom in the Kameeldrift area. About 80 meters after touchdown, the aircraft collided with a fence and small bushes, veering off the road to the right. It then struck a sand embankment, causing the nose gear to separate. The aircraft overturned and came to rest inverted. Both occupants vacated the aircraft with no injuries, although the aircraft was extensively damaged.
Probable Cause
The probable cause was determined to be that during a simulated engine failure to demonstrate asymmetric flight and VMCA, the left-hand engine was shut down and failed to restart. The aircraft could not maintain altitude on the right-hand engine alone, resulting in a forced landing on a dirt road. During the landing, the aircraft collided with a fence and small bushes to the right of the road, which caused it to veer off the right side and overturn.