What happened
On August 30, 2015, a Zlín Z 43, registration OK-DOJ, was conducting a local flight near the Lysá hora mountain range in the Czech Republic. The flight, operated by Aeroklub Frýdlant nad Ostravicí, was carrying the pilot and three passengers.
While flying over the valley of the Jestřábí potok stream, the pilot was climbing at approximately 300 m AGL. As the aircraft approached the ridge between the Malchor and Kykulka mountains, the pilot attempted a right-hand turn to avoid the higher terrain. During this maneuver, the aircraft encountered intense turbulence and a significant loss of airspeed, dropping below 140 km/h. The pilot, attempting to maintain control and avoid a continued descent, opted to abandon the turn and instead attempted to fly straight over the ridge using takeoff power.
Due to insufficient altitude, the aircraft struck the tops of tall trees on the northern slope of the ridge. Despite the impact, the pilot maintained control of the aircraft and successfully returned to land at LKFR (Frýdlant nad Ostravicí) without further incident. The aircraft sustained damage to the leading edges of both wings, the horizontal stabilizer, the lower fuselage skin, and the propeller blades. There were no injuries to the pilot or the three passengers.
The investigation
The ÚZPLN investigation examined the pilot's flight planning, the meteorological conditions, and the aircraft's technical state. Investigators analyzed the wind conditions at the time, noting that while surface winds were light, higher-altitude winds (up to 25 kt at 5000 ft) were creating mechanical turbulence and rotor effects on the leeward side of the mountains. The investigation also reviewed the pilot's experience, noting that while highly experienced in general aviation, he had limited experience specifically with the Zlín Z 43 type.