What happened
On June 23, 2021, a Diamond DV 20 Katana departed from Ried-Kirchheim, Austria, bound for Braunschweig-Wolfsburg, Germany. The aircraft was operated by an Austrian flying club and was being flown by a single pilot under Visual Flight Rules (VFR).
During the cruise phase, the aircraft climbed above FL100. Air traffic services at Langen Information notified the pilot that he was entering Class C airspace without authorization and instructed him to remain below FL95. The pilot responded that he was attempting to climb above the clouds to maintain VFR conditions. While the controller coordinated the aircraft's presence in Class C airspace, the pilot reported being inside a cloud mass and requested time to maneuver.
Radar data indicates that shortly after 13:31 local time, the aircraft began a right-hand turn, likely an attempt to execute a turn-back to regain visual contact with the ground. However, the aircraft's flight path became erratic, characterized by rapid changes in direction and extreme vertical oscillations, including a descent rate of up to 10,000 ft/min. The aircraft struck the ground near Straßenreuth at a high forward speed. The pilot sustained fatal injuries, and the aircraft was destroyed.
The investigation
The BFU examined radar data from the Döbraberg radar station, which tracked the aircraft's final minutes. The investigation also included a meteorological analysis by the German Meteorological Service (DWD) and an examination of the aircraft wreckage. Investigators found no evidence of engine failure, structural failure, or issues related to weight and balance. The engine was found to be in good working order, and the aircraft was within its center of gravity limits.
Findings
- The primary cause of the accident was the entry into instrument meteorological conditions (IMC).
- The pilot's assessment of the meteorological conditions for VFR flight was inadequate.
- The pilot continued the flight despite the approaching cloud ceiling.
- The pilot lacked the necessary instrument rating (IR) to fly in the encountered weather conditions.
- The aircraft encountered convective clouds with embedded cumulus, which likely produced turbulence and potentially icing conditions, contributing to the loss of control.