What happened
On September 18, 2021, a private pilot and a passenger were conducting local flights near the Torca Aerodrome (SCLI) in the Maule Region of Chile. After completing an initial flight, the crew decided to perform a second local flight. To save time, the pilots swapped seats to change roles without shutting down the engine.
During the takeoff roll on runway 20, the aircraft performed normally and reached a rotation speed of 6/0 knots. However, only seconds into the initial climb, the engine suffered a sudden and total loss of power. The pilot attempted to restart the engine by switching the fuel selector to the right tank, but the maneuver was unsuccessful. The pilot was forced to perform an emergency landing on unprepared terrain southwest of the aerodrome. Both occupants remained uninjured, though the aircraft sustained significant damage.
The investigation
DGAC Chile investigators examined the aircraft's maintenance records and the physical state of the fuel system. The investigation confirmed that the aircraft had undergone a recent annual inspection and that all maintenance was performed by an authorized facility. The engine and propeller were inspected for damage caused by the impact of the landing.
Investigators analyzed the fuel levels and the fuel selector valve's operation. They found that while the main tanks contained sufficient fuel, the auxiliary tank was empty. The investigation focused on the period when the pilots swapped seats while the engine was running, looking for any mechanical or procedural errors that could have interrupted the fuel flow.
Findings
- The engine stopped because the fuel flow was interrupted due to the fuel selector being moved to an empty tank.
- During the seat swap, the fuel selector lever was inadvertently moved from the left main tank to the left auxiliary tank.
- The fuel selector valve lacked sufficient resistance or a pronounced detent, making it easy to move accidentally.
- The visual markings on the fuel selector face may have caused confusion, preventing the pilot from realizing the valve had been moved during the quick pre-flight check.
- The engine continued to run for a short period after the switch because residual fuel remained in the fuel lines, but the supply was exhausted during the climb.