What happened
On July 19, 2019, a Piper PA-28-140, registration EC-GDC, departed from Madrid - Cuatro Vientos Airport (LECU) for a local private flight. The aircraft was flying over the Buendia reservoir when, at an altitude of approximately 3,500 feet, the engine began to vibrate significantly. The engine revolutions dropped from a target of 2,300–2,350 rpm to approximately 1,900 rpm.
The pilot attempted several emergency procedures to restore power, including switching fuel tanks, engaging the fuel pump, and adjusting the fuel mixture. Although the engine briefly regained some RPM, the power loss persisted. After being unable to maintain altitude, the pilot declared a MAYDAY and identified a nearby cornfield for an emergency landing. The pilot performed a controlled approach using full flaps, cutting the engine and fuel mixture just before touchdown in the field.
The investigation
The investigation examined the aircraft's maintenance history and the circumstances of the engine failure. The aircraft had undergone a routine 50-hour maintenance inspection only three days prior to the accident, which included an oil and filter change.
Investigators found that the engine's oil tank was completely empty, with less than 2 liters of poor-quality oil remaining in the sump. Additionally, an analysis of the wreckage revealed that the mixture control cable was non-functional. It is important to note that the aircraft's owner dismantled and destroyed the fuselage and engine for metal recycling before the CIAIAC could examine the wreckage, which limited the availability of certain physical evidences.
Findings
- The primary cause of the accident was the in-flight engine power loss which necessitated an emergency off-airfield landing.
- The engine suffered from a critical lack of lubrication, as the oil tank was empty and the remaining oil was of poor quality.
- The pilot and passenger sustained minor injuries during the impact.
- The aircraft sustained significant damage to the landing gear, nose, and wings.