G-force changes likely cause of Singapore flight injuries, probe finds

Singapore’s Ministry of Transport says Boeing aircraft experienced 54-metre altitude drop during incident.

Dozens of passengers suffered injuries on a Singapore Airlines flight due to “rapid changes” in gravitational force and a 54-metre altitude drop, a preliminary investigation has found.

A 73-year-old British man died of a suspected heart attack and dozens of passengers were injured last week when Singapore Airlines flight SQ321 was buffeted by severe turbulence, forcing the plane to make an emergency landing in Bangkok.

Singapore’s Ministry of Transport said in a statement on Wednesday that a rapid change in G-force resulted in passengers who were not wearing their seatbelts becoming airborne.

“At 07:49:41 hr, the vertical acceleration changed from -ve 1.5G to +ve 1.5G within 4 sec. This likely resulted in the occupants who were airborne to fall back down,”  the ministry said, citing an examination of the flight data recorder and cockpit voice recorder.

“The rapid changes in G over the 4.6 sec duration resulted in an altitude drop of 178 ft, from 37,362 ft to 37,184 ft. This sequence of events likely caused the injuries to the crew and passengers.”

The ministry said investigations into the incident, involving officials from the Transport Safety Investigation Bureau of Singapore, United States regulators and Boeing, were continuing.

Singapore Airlines said that it was “fully cooperating” with the relevant authorities in the investigations into the incident.

“The safety and well-being of our passengers and staff are our top priorities. We are committed to supporting our passengers and crew members who were on board SQ321 on that day, as well as their families and loved ones. This includes covering their medical and hospital expenses, as well as any additional assistance they may need,” the airline said in a statement.

Singapore Airlines said last week it was adopting “a more cautious approach to managing turbulence in-flight” following the incident, including discontinuing its meal service when the seat belt sign is on.