What happened
On 2 March 2008, a TECNAM P2/02-JF, registration EC-JLQ, was performing a private flight from Sabadell to Pamplona and back to Sabadell. During the return leg, approximately one hour into the flight, the pilot noticed a drop in oil pressure. Shortly thereafter, the engine began to sputter and lose power. Within two minutes, the propeller stopped completely, resulting in a total loss of engine power. The pilot declared an emergency with Barcelona Control and executed an emergency landing in a field west of Tárrega, Lleida. The pilot escaped without injury, and the aircraft sustained only minor damage, though the engine was destroyed.
The investigation
Investigators examined the ROTAX 912S2 engine and discovered that both the intake and exhaust valves on the number 2 cylinder had fractured. This failure caused a piece of the valve to lodge between the piston and the cylinder head, perforating the piston and damaging the cylinder head. The investigation also scrutinized the aircraft's maintenance history, finding significant discrepancies in the engine logbook. Specifically, there were missing entries regarding maintenance activities and a lack of evidence that required inspections, such as the 800-hour propeller gearbox check, had been performed. Furthermore, the investigation noted that the engine was being operated using AVGAS 100LL, which requires more frequent oil changes and inspections due to increased carbon deposits and valve seat wear, yet these shortened intervals were not being followed.
Findings
- The primary cause of the engine failure was the fracture of a valve in the number 2 cylinder, which subsequently caused the second valve to break.
- The engine was being operated with AVGAS 100LL, which increases the risk of valve seat wear and carbon buildup, yet the required increased maintenance frequency was not implemented.
- There was a lack of proper oversight regarding the aircraft's continued airworthiness by the operator.
- Maintenance records were disorganized, with incomplete or non-existent entries regarding various inspections and engine hours.
- The engine had exceeded its recommended service life intervals for specific inspections without documented verification of their completion.