What happened
On June 15, 2021, at approximately 19:15 UTC, a TOMI CROSS 5 powered hang glider, registration OK-ZZA 21, crashed in a field approximately 700 meters north of Polička, Czech Republic. The pilot was conducting a second sightseeing flight of the evening, carrying one passenger, after having previously completed one flight with a different passenger.
During the flight, the pilot attempted a series of maneuvers involving an S-shaped flight path. While performing a left-hand turn at an altitude of approximately 200–250 meters AGL, the aircraft transitioned from a high bank angle into a steep, descending spiral. The descent reached a longitudinal slope of more than 50 degrees and a bank angle exceeding 80 degrees. Due to the low altitude, the pilot was unable to recover the aircraft before impact. The collision resulted in two fatalities.
The investigation
The ÚZPLN investigation examined several factors, including witness testimonies, video footage from a nearby radar station, and the physical wreckage. Investigators analyzed the aircraft's technical state, the engine performance, and the meteorological conditions at the time of the accident.
Technical analysis of the TOMI CROSS 5 revealed that the aircraft was configured with a "heavy nose" balance, a setting intended to reduce control forces at higher speeds but which increases control difficulty at lower speeds. The investigation also calculated the aircraft's weight, finding that the total weight was at least 6.5 kg above the maximum takeoff weight (MTOW), a figure that likely increased when accounting for the full fuel load. The engine was found to have been operating at a reduced power setting during the critical phase of the maneuver, and the parachute recovery system was not deployed.
Findings
- The pilot performed a maneuver involving a high bank angle and a transition into a steep descent without sufficient engine power at a low altitude.
- The aircraft was operating above its maximum takeoff weight.
- The aircraft's "heavy nose" trim configuration made control more difficult during the low-speed phase of the maneuver.
- A tailwind component during the turn contributed to a reduction in airspeed and lift.
- Orographic turbulence caused by nearby terrain and wind conditions may have further affected the aircraft's stability.