Incident Overview
On November 19, 2012, a commercial Boeing 767-300 with registration I-NDMJ was operating flight NO731 from Havana (MUHA) to Milan Malpensa (LIMC). During the cruise phase at Flight Level 350, approximately 100 nautical miles west of the route point BALTN in the Atlantic Ocean, the aircraft encountered an unexpected area of severe turbulence. The event occurred around 05:15 UTC.
Crew and Passenger Impact
The sudden changes in attitude and altitude resulted in injuries to several individuals on board. Among the crew, one member sustained serious injuries while two others suffered minor injuries. On the passenger side, one person was seriously injured and 34 others sustained minor injuries. Additionally, light damage occurred to the cabin interior, particularly in the rear section, caused by unsecured catering trolleys and passenger impacts. Two medical professionals on board assisted with first aid during the remainder of the flight.
Operational Response and Investigation
The flight data recorder indicated the turbulence lasted approximately 35 seconds, with vertical speeds reaching up to +6,100 ft/min and pitch oscillations between -2.5° and +12.7°. The pilot in command decided to continue to the planned destination rather than diverting to an alternate airport, as the aircraft remained airworthy and no passengers were in life-threatening danger. Diverting would have required re-entering the turbulent area.
The investigation determined that the severe turbulence was likely clear-air turbulence (CAT) associated with a jet stream. It was not reported by other aircraft, absent from SIGMETs, and undetectable by the onboard weather radar due to low humidity in the convective movements.