What happened
On January 3, 2014, a student pilot was conducting a solo training flight at Strakonice Airport (LKST). After refueling the Robinson R44 Raven II, registration OK-EEE, the pilot began engine start-up procedures while positioned near a fuel station. As the engine RPM increased above 80% and the governor engaged, the helicopter began to rotate to the right.
In an attempt to quickly move the aircraft away from the nearby fuel station, the pilot performed an abrupt takeoff. During this maneuver, the pilot applied excessive collective and cyclic inputs, causing the tail rotor skid to strike the ground. The aircraft then experienced a sudden pitch change before the pilot, attempting to land quickly, executed a hard landing on the asphalt surface. The pilot was uninjured, but the aircraft sustained damage to the vertical stabilizer, tail skid, and landing gear.
The investigation
The ÚZPLN investigation examined the pilot's actions, the aircraft's mechanical condition, and the takeoff environment. Investigators found that the pilot had failed to verify that the pedals were in the neutral position during pre-start checks. The investigation also noted that the instructor, who was monitoring the flight from the ground, could not have prevented the incident due to its rapid progression, though a different takeoff location might have been safer.
Technical inspections of the Robinson R44 Raven II confirmed that all flight controls, engine components, and transmission parts were fully functional and that no mechanical failures contributed to the event. The aircraft was within its permitted weight and center of gravity limits.
Findings
- The primary cause of the incident was the unintentional application of the right pedal, which allowed the helicopter to rotate on the ground as engine torque increased.
- The pilot's reaction to the rotation—an abrupt and improper takeoff to avoid the fuel station—led to the tail strike.
- The subsequent hard landing was a result of the pilot's attempt to land immediately following the unstable flight path.
- The proximity of the fuel station influenced the pilot's hurried and inappropriate decision-making during the critical situation.