'Rapid changes' in G-force, altitude drop likely caused injuries to unbelted passengers and crew on SQ321
Rapid changes in gravitational forces (G-forces) along with an altitude drop likely cause the injuries to unbelted crew and passengers on Flight SQ321, according to the findings of a preliminary investigation.
In a statement on Wednesday, investigators from the Transport Safety Investigation Bureau (TSIB) said that there was a «rapid change» in G-force over 4.6 seconds, resulting in the injuries. This was based on findings from data stored in the flight data recorder and cockpit voice recorder.
The TSIB is the air, marine and rail accidents and incidents investigation authority in Singapore and is part of the Ministry of Transport (MOT).
Investigators found that the flight, which departed from London on May 20, was normal prior to the turbulence incident.
At around 3.49.21pm (Singapore time) on May 21, the aircraft flew over the south of Myanmar at an altitude of 37,000 ft (11,300m) and was «likely flying over an area of developing convective activity,» MOT stated.
Turbulence started to cause fluctuations between +0.44G and +1.57G for a period of 19 seconds.