What happened
On 12 February 2010, a Reims F172M, registration ZS-PYL, departed Rand Aerodrome for a local pleasure flight. The aircraft was carrying the pilot and two passengers. While climbing through approximately 500 feet above ground level, the engine suddenly lost power and ceased operation.
After an unsuccessful attempt to restart the engine, the pilot notified Rand Air Traffic Control of the intention to perform an emergency landing. The aircraft proceeded to an open field at Tulisa Park near Alberton. During the landing sequence, the aircraft struck a pile of rocks, causing substantial damage to the nose, propeller, right wing, and landing gear.
The investigation
Investigators examined the wreckage and analyzed data from the aircraft's Full Authority Digital Engine Control (FADEC) system. The FADEC data confirmed a sudden drop in fuel pressure to zero bars shortly after takeoff.
Subsequent teardown of the engine revealed that the slide bearing within the fuel high-pressure pump (HPP) and the bearing seats of the eccentric shaft were extremely worn. Metal debris from these worn components had been distributed throughout the entire fuel system. Laboratory analysis of fuel samples confirmed the presence of metallic particles consistent with the damaged bearing.
Findings
- The engine failure was triggered by a sudden loss of fuel pressure.
- The primary cause of the pressure drop was the failure of a bearing inside the fuel high-pressure pump.
- The engine's maintenance schedule had not been strictly followed; specifically, the high-pressure pump was not replaced at the required 600-hour interval, as the engine had accumulated 805.4 hours since the original pump was installed.
- All occupants escaped the incident without injury.