What happened
On July 8, 2012, a Bombardier DH8D was operating a scheduled flight from Frankfurt to Wrocław. While cruising at flight level 230 within the Czech FIR, the aircraft encountered a short-lived area of intense turbulence. At the time of the event, the aircraft was flying in instrument conditions (within clouds). Although the flight crew was actively monitoring the onboard weather radar, no significant weather hazards had been previously reported or identified by the crew.
Despite the "fasten seatbelt" sign being illuminated, the severity of the turbulence caused one passenger to strike a bulkhead overhead, resulting in a laceration to the head. The cabin crew provided immediate first aid. Because the injury was not considered serious, the crew decided to continue the flight to Wrocław. The flight crew notified Air Traffic Control of the situation and requested medical assistance upon arrival. Emergency services met the aircraft on the apron at Wrocław, and the passenger was subsequently transported to a hospital for sutures.
The investigation
The investigation examined the weather reports, ATIS information, and the crew's monitoring of the onboard radar. It was established that the turbulence was unexpected, as meteorological reports and ATIS did not indicate the presence of thunderstorm cells or known turbulence zones in the flight path. The investigation also reviewed the cabin status, confirming that the seatbelt sign was active during the encounter.