What happened
On October 9, 2021, a Piper PA-18A-150, registration LV-GBY, departed from Trevelin, Chubut, for a local recreational flight. While cruising over Lago Rosario at approximately 21:30 UTC, the engine suddenly stopped. The pilot attempted to restart the engine by switching the fuel tank selector, but the engine failed to relight. Consequently, the pilot performed an emergency landing on the surface of the lake. The pilot and one passenger were able to evacuate the aircraft safely and sustained only minor injuries.
The investigation
The investigation focused on the cause of the engine failure and the subsequent emergency landing. Upon recovering the aircraft and returning it to a hangar, investigators discovered that the fuel selector valve was in the closed position. The aircraft's fuel system was inspected, and no mechanical obstructions or failures were found in the fuel delivery lines.
Analysis of the fuel selector mechanism—located to the left of the pilot's seat—revealed that moving the lever to the left (toward the rear of the seat) closes the fuel supply. The investigation established that the aircraft had been operating using the right tank prior to the failure. The pilot intended to switch to the left tank but inadvertently moved the selector into the closed position.
Findings
- The engine failure was caused by incorrect fuel tank selection.
- There were no mechanical defects or interruptions found within the aircraft's fuel system.
- The pilot attempted to switch tanks during the engine failure but did not verify that the new tank was properly engaged, effectively cutting off the fuel supply to the engine.