What happened
On July 28, 2017, a Robinson R22 BETA II helicopter, registration OK-HLC, was engaged in a series of low-altitude training maneuvers at Hradec Králové Airport (LKHK). The flight was being conducted by a student pilot under the supervision of an experienced instructor. The objective of the flight was to practice hovering and lateral transitions at a very low altitude, specifically using an asphalt path as a visual reference.
During the execution of a left lateral hover, the student pilot failed to maintain the aircraft's heading, allowing the nose to swing significantly to the right. In an attempt to correct this deviation, the student applied a sudden, heavy left pedal input combined with left cyclic movement. This uncoordinated input caused the aircraft to descend rapidly while continuing its lateral movement. Consequently, the left skid struck a slightly elevated section of the asphalt surface. The impact caused the helicopter to roll sharply to the left, leading the main rotor blades to strike the ground and the aircraft to overturn onto its left side.
The investigation
The ÚZPLN investigation focused on the flight sequence, the crew's actions, and the mechanical condition of the aircraft. Investigators examined the wreckage and the site, noting that the contact point involved a section of the pavement that was higher than the surrounding area. Technical inspections of the Robinson R22 BETA II confirmed that all control systems, the engine, and the drive components were fully functional prior to the impact. The damage to the tail boom, tail rotor, and main rotor blades was determined to have been caused solely by the impact with the ground during the rollover.
Findings
- The student pilot lacked sufficient experience in low-altitude maneuvering and failed to maintain situational awareness regarding the aircraft's altitude.
- The student's corrective actions were uncoordinated, specifically the heavy left pedal input which induced a rapid descent.
- The instructor, while attempting to intervene, did not move the collective to the fully low position during the onset of the left roll.
- The left skid caught on a fixed point on the ground, and the crew's subsequent control inputs failed to prevent the roll.
- The instructor sustained serious injuries requiring hospitalization and rehabilitation, while the student pilot sustained minor injuries.