What happened
On October 1, 2019, a Grumman G-164-A, registration LV-FUD, departed from the Villa Dolores aerodrome in Córdoba, Argentina, to conduct agricultural flight training maneuvers. Approximately 30 minutes into the flight, while performing a low pass, the aircraft experienced a sudden engine failure characterized by a drop in RPM and a loss of power insufficient to maintain flight levels.
Due to the inability to return to the departure airfield, the pilot performed an emergency landing in an unprepared field. Because other nearby fields were occupied by workers, the pilot was forced to land in a harvested area where the furrows were 40 cm deep. The aircraft crossed these furrows at a 90-degree angle, causing the right main landing gear to collapse and the aircraft to capsize. The aircraft traveled approximately 45 meters before coming to a complete stop. The pilot sustained no injuries.
The investigation
Investigators examined the engine's carburetor and analyzed the aircraft's fuel and oil. While the carburetor showed no mechanical component failure, it exhibited advanced deterioration due to sediment buildup, suggesting an extended interval between inspections.
Laboratory analysis confirmed the use of SAE 20W50 lubricant, which was found to be suitable for use. However, the AV-GAS 100LL fuel was found to be contaminated with synthetic particles. The size of these particles posed a significant risk of clogging the fuel delivery circuits.
Findings
- The engine's drop in RPM was caused by a lack of sufficient fuel supply to the carburetor.
- The contaminated fuel contained synthetic particles large enough to obstruct the engine's fuel delivery system.
- The resulting loss of power prevented the pilot from maintaining the flight path, necessitating the emergency landing.
- The structural damage to the aircraft, including the landing gear collapse, was caused by landing across the direction of the harvested furrows in an unprepared field.
Safety action
- The aircraft owner should implement more effective monitoring and control of component conditions prior to service to ensure proper functionality.