What happened
On February 23, 2023, at approximately 18:40 local time, a Schweizer 269C helicopter, registration HA-HBQ, was conducting night flight training near Páty, Hungary. The flight involved an instructor and a student performing autorotation practice outside of an airfield. During the maneuver at approximately 2,000 feet, the engine failed to respond to power increases. Due to the limited time available before ground impact, the crew did not attempt an engine restart and continued the descent in an emergency autorotation mode.
The aircraft touched down on soft, plowed soil. During the subsequent ground slide, the helicopter's nose pitched forward. In an attempt to counteract this pitch, the instructor applied excessive forward cyclic input, causing the main rotor blades to strike the tail boom. The impact caused the helicopter to rotate 180 degrees and capsize onto its right side. There were no injuries to the crew, but the aircraft was significantly damaged.
The investigation
The KBSZ investigation examined the mechanical state of the aircraft, interviewed the crew, and reviewed maintenance and flight planning records. Investigators found that a maintenance technician had previously adjusted a binding throttle linkage at Budaörs Airfield following a reported issue; however, this work was not documented in any logbook.
The investigation also looked into the crew's preparation, noting that the student had not participated in the pre-flight inspection and that the flight plan for the night VFR training had been submitted via telephone only shortly before the incident. The investigation focused on why the engine failed to respond and how the aircraft's attitude changed during the ground slide.