What happened
On August 6, 2016, a Be-50 Beta Minor, registration OK-EAA, was performing a short flight near Mladá Boleslav airport. The flight, which included the pilot and one passenger, proceeded without issue under CAVOK conditions, though significant thermal turbulence was present.
During the final approach to runway 34, the aircraft was at an altitude of approximately 80 meters with flaps set to 45% and the engine at idle power. The pilot initiated a slight slip to adjust the energy profile after the aircraft briefly climbed due to thermals. Shortly thereafter, the aircraft began a rapid descent. As the pilot attempted to correct the descent and maintain a stable approach, the aircraft suddenly lifted to an altitude of approximately 5 meters above the ground. During this phase, the control column became unresponsive to pilot inputs. The aircraft lost forward airspeed and impacted the runway approximately 150 meters from the threshold with a slight right bank. The impact was severe enough to cause an audible strike from the right landing gear strut.
The investigation
The ÚZPLN investigation examined the aircraft's condition, the pilot's actions, and the meteorological conditions at the time of the accident. The investigation confirmed that the pilot held a valid CPL and medical certificate, and the aircraft was airworthy with a valid special airworthiness certificate. The investigation focused on the sudden loss of control and the subsequent structural damage found during a detailed inspection of the airframe.
Findings
- The primary cause of the accident was wind shear encountered during the final stage of the approach.
- This wind shear caused the aircraft to be blown upward, subsequently leading to a loss of airspeed and a subsequent drop in altitude.
- The aircraft became unresponsive to control inputs during the critical phase of the landing.
- The impact with the ground resulted in cracks in the plywood and bonded joints of the right wing center section, including the main spar and fuel tank attachments, as well as damage to the right wing tip rib and the right landing gear fairing.
- There were no injuries to the pilot or the passenger.