Accident Overview
On 18 July 2009 at approximately 1330Z, a Beech 36 (registration ZS-MPB) operated by a private pilot on a VFR flight from Stellenbosch aerodrome (FASH) to Upington International Airport (FAUP) experienced an uncontained engine failure. About two hours into the flight, the pilot detected the smell of oil and smoke in the cockpit, followed by a loss of oil pressure.
Forced Landing
Believing the aircraft was about to catch fire, the pilot switched off the master switch to prevent electrical sparks. He then selected "gear down" but did not attempt to lower the landing gear manually, assuming it had already extended. The aircraft landed on a gravel road approximately 25 km west of Kenhardt in the Northern Cape with the landing gear retracted.
Damage and Injuries
The aircraft sustained damage to the engine, undercarriage, and propeller. The pilot was not injured. No evidence of fire was found in flight or on the ground.
Maintenance History
Prior to the flight, the aircraft had undergone maintenance at an approved AMO to replace a worn starter clutch. The replacement part lacked an optional air-conditioning drive, requiring the installation of a clip seal retainer to secure the oil seal. The clip seal retainer was omitted during installation, allowing the oil seal to become partially detached during flight. This resulted in loss of engine oil, causing the engine to seize and undergo an uncontained failure.
Probable Cause
The probable cause stated in the official report is: "The electrical master switch was disarmed during the uncontained engine failure in flight, and thereafter the emergency system was not utilised to lower the landing gear, resulting in a wheels-up landing." Contributory factors included the omission of the clip seal retainer during starter clutch installation and the pilot's inadequate knowledge of the aircraft's emergency systems and procedures.