Description

On 26th May 2003, a British Midland AIRBUS A-321 suffered severe damage from hail en route near Vienna.

Synopsis

This is the synopsis from the official report into the incident published by the UK AAIB.

"The aircraft was in the cruise at FL340 approximately 70 nm south-east of Vienna when it encountered an area of severe turbulence and hail. Some of the flight deck windows became crazed and other areas of the airframe suffered extensive damage although this was not apparent to the crew. The aircraft made a precautionary descent to FL230, in accordance with the required abnormal procedures, and continued the flight to its destination of Manchester. The crew had no indication or warning that the aircraft was about to enter an area of severe turbulence, associated with the upper levels of a Cumulonimbus cloud. When they had been using the weather radar to check the route ahead of the aircraft, sometime before the encounter, the radar returns appeared benign."

Here is an extract from the flight history which details what happened when the aircraft encountered the Cb:

"The radar was set to a scale of 160 nm and with no significant returns ahead and no thunderstorm activity forecast the radar was switched OFF. The aircraft had been in clear skies above towering Cu for most of the flight and, in accordance with normal procedures, the radar had only been turned on when required."