Accident Details
On 29 June 2001, at 1100Z, a Beech F33A aircraft, registration ZS-INH, departed Grand Central Aerodrome on a private flight to Nelspruit Aerodrome. While near Witbank, the pilot suddenly experienced a propeller overspeed condition. As Witbank Aerodrome was beyond gliding distance, the pilot executed a forced landing on an open field near the Witbank coal mine. During the landing roll, the aircraft traversed a ditch, causing the nose landing gear to separate, the left main landing gear to collapse, and the propeller to contact the ground. The aircraft sustained substantial damage, but the pilot was not injured. The accident occurred during daylight conditions with fine weather.
Aircraft Information
The Beech F33A (ZS-INH) had a last mandatory periodic inspection (MPI) at a total of 3488.53 airframe hours, and the accident occurred 65.53 hours after that MPI and after the engine was overhauled. The pilot held a private pilot license with a total of 148.10 flying hours, of which 60.60 hours were on type. The license was valid.
Probable Cause
The camshaft fractured at the number 3 camshaft bearing machined oil transfer pick-up point, causing the constant speed unit (CSU) bevel gear to become ineffective. This resulted in the propeller overspeed with partial loss of power. The subsequent forced landing on an open field led to substantial damage to the aircraft.