What happened
On September 5, 2020, a Tecnam P 92 Echo Super, registration OK-QUU 90, was conducting a recreational navigation flight near Rokycany. After a brief stop at the Buranos Aires airfield (LKBURA), the flight continued toward the Berounka river. Approximately 18 minutes into the flight, the pilot noticed a significant discrepancy between the fuel levels indicated in the left and right tanks.
In an attempt to equalize the levels, the pilot performed a 36/0-degree turn and subsequently closed the fuel valve for the right tank, while activating the electric fuel pump. This action inadvertently cut off the supply from the right tank, which still contained a significant amount of fuel. As the fuel in the left tank was depleted, the engine began to lose power and eventually failed. The pilot attempted an emergency landing in a plowed field approximately 1.12 km east of Rokycany. During the landing, the aircraft struck high-voltage power lines, hit the ground hard, and overturned onto its back. While the pilot sustained minor injuries, the passenger was knocked unconscious and died four days later in the hospital.
The investigation
The ÚZPLN investigation focused on the fuel system, the pilot's actions, and the aircraft's technical condition. Investigators examined the fuel levels, noting that while the aircraft had been refueled with 42 liters total, the aircraft had been parked on a slight slope for 90 minutes prior to departure. This caused approximately 12 liters of fuel to flow from one tank to the other. The investigation also included an engine expertise and a review of the pilot's flight maneuvers.
Findings
- The pilot failed to perform a physical fuel level check using a mechanical dipstick after the aircraft had been parked on an incline.
- The pilot performed an unnecessary 360-degree turn to check fuel levels.
- The pilot closed the right fuel tank valve in direct contradiction to the flight manual, which led to the depletion of the left tank.
- The pilot failed to check the fuel valves or reopen the right valve when the engine began to lose power and RPM fluctuated.
- The engine stopped because the fuel supply was interrupted by the incorrect manipulation of the fuel valve.
- The landing was performed at a low speed with flaps extended, but the hard impact on the plowed field caused the nose gear to collapse and the aircraft to flip.