What happened
On 9 June 2020, a Piper PA-28R-200, registration EC-HLV, was conducting a local flight for instructor retraining near Madrid - Cuatro Vientos airport. The flight, operated by AEROFAN ATO, involved two flight instructors performing take-off and landing practice following a period of aircraft inactivity.
While flying near Valmojado, the crew simulated an engine failure. During this maneuver, the engine began operating erratically. Upon increasing power to return to the departure airport, the engine began producing explosive noises and violent vibrations. The crew subsequently decided to divert to Casarrubios del Monte Aerodrome (LEMT) for an emergency landing. During the diversion, the aircraft experienced a power supply interruption, which hindered communications and prevented the crew from verifying the landing gear status. During the approach, the crew failed to properly configure the aircraft, resulting in the plane striking the ground with the landing gear retracted.
The investigation
The CIAIAC examination focused on the engine's mechanical state, the maintenance history of the aircraft, and the crew's emergency management. Investigators analyzed the engine components, finding significant contamination and mechanical failures. The investigation also reviewed the maintenance records of the EASA Part 145 organization responsible for the aircraft's upkeep and evaluated the operational procedures followed by the flight instructors during the emergency.
Findings
- The primary cause of the accident was a lack of adherence to operational procedures, specifically regarding the landing gear configuration.
- The engine failure was caused by the failure of cylinder no. 4, which resulted from insufficient lubrication. This was due to a build-up of contaminants and silicone particles in the lubrication holes.
- Improper engine maintenance was identified, as the lubricating oil was heavily contaminated with metallic and organic particles, and the oil had not been changed in accordance with manufacturer recommendations for aircraft in inactivity.
- The automatic landing gear extension system had been left in the OVERRIDE position.
- The investigation found that the maintenance organization's management was deficient, with findings inconsistent with their provided documentary records.
- The crew's experience in this specific aircraft type was limited, with the pilot flying having only 3.2 hours in the model.