What happened
On May 31, 2022, an instructor and a student pilot were conducting solo flight training maneuvers at the Babice (EPBC) aerodrome in a Piper Pa-28-140, registration OK-EVR. During the pre-flight inspection, the crew noted a significant imbalance in fuel levels, with the left tank containing over 17 gallons and the right tank containing approximately 5 gallons. They determined this quantity was sufficient for the planned training session.
After completing three supervised circuits, the instructor authorized the student to perform solo circuits. During the second solo circuit, while executing a turn at approximately 1,800 ft and 70 kt, the student noticed a loss of engine power as the tachometer dropped to 800 RPM. Despite verifying the throttle and mixture settings and activating the fuel pump, the engine failed to recover. The student pilot declared a "Mayday" on the Babice Radio frequency, announcing an engine failure and an emergency landing. The aircraft subsequently landed in a field near the ZULU point and the North Bridge. The landing was completed without damage to the aircraft, and the student pilot exited the cabin uninjured.
The investigation
The PKBWL investigation focused on the sequence of events leading to the engine power loss and the fuel levels identified during the pre-flight inspection. The investigation examined the fuel management practices of the flight crew and the procedures implemented by the Approved Training Organization (ATO) following the incident.
Findings
- The primary cause of the engine power loss was improper fuel management.
- The significant imbalance between the fuel tanks was known prior to takeoff but was deemed acceptable for the mission.
Safety action
Following the incident, the ATO implemented several new procedures to prevent recurrence, including:
- Requirements to fuel both tanks to at least 17 gallons before a student's first solo flight, and to full capacity for night or cross-country flights.
- A mandate that the maximum fuel difference between tanks must not exceed 10 gallons.
- Standardization of the fuel tank switching procedure (fuel pump on, pressure check, tank change, pressure check, fuel pump off).
- Implementation of 30-minute GPS reminders to check fuel tank levels.
- Instructors are now required to reinforce the use of checklists and the necessity of switching tanks every 30 minutes.