BFU Switzerland concluded the investigation into a hail storm encounter occurrence. After taking off from runway 23 at Geneva airport, the flight crew of the Boeing 737-33V on
flight EZS 903 destination Luton turned right in accordance with standard instrument departure DIPIR 1A; they were cleared to climb to flight level FL 150, then FL 180. When
passing flight level FL 85 in a climb, they requested clearance to maintain heading 310 in order to avoid thunderstorm cells. A few minutes later, the aircraft passed through a shower of hail which seriously damaged it. After declaring a distress situation – `MAYDAY MAYDAY
MAYDAY` – the flight crew were authorised to return to Geneva airport. The landing on runway 05 took place without any problems and the aircraft then reached its stand. None of the occupants was injured and passengers disembarked normally.
The accident was caused by the aircraft flying into a shower of hail embedded in a thunderstorm cell, following inadequate utilisation of the information provided by the onboard weather radar.
The following factors played a part in the accident:
– shortcomings in crew resource management (CRM);
– no specific meteorological information concerning this hazard was transmitted. (BFU)