What happened
On 17 February 2024, a Tecnam P92 aircraft, registration ZS-PWR, was conducting a navigational training flight from Springs Aerodrome to Bram Fischer International Airport. The flight, operated under Part 1/41 regulations, was being conducted by a flight instructor and a student pilot under visual meteorological conditions.
After completing a successful touch-and-go landing at Bram Fischer, the aircraft climbed to 6,000 feet for the return leg. While flying approximately 20 nautical miles northeast of the airport, the flight instructor noticed a drop in engine oil pressure. During the subsequent attempt to return to the airport, a loud bang was heard from the engine, followed by rough running and total engine failure. The instructor took control of the aircraft and issued a Mayday call. The crew successfully glided the aircraft into an open field, executing a safe forced landing. There were no injuries and no damage to the aircraft.
The investigation
SACAA AIID investigators examined the engine and the aircraft's Engine Control Unit (ECU) data. Post-flight inspection of the engine revealed oil residue on the underbelly and a hole in the crankcase. The investigation established that the Number 1 connecting rod had failed, protruding through the engine casing.
Analysis of the oil pump revealed it was defective and contained metal particles. Data retrieved from the ECU confirmed the decline in oil pressure and the subsequent fluctuations in engine parameters leading up to the engine's cessation. The investigation also confirmed that the aircraft's maintenance was up to date, having undergone a mandatory periodic inspection only 2.9 hours prior to the incident.