The Singapore Airline’s flight caught in severe turbulence last week dropped 178 feet in less than 5 seconds, Singapore’s Transport Safety Investigation Bureau (TSIB) has found in its preliminary investigation.
The sudden drop in altitude “likely caused the injuries to the crew and passengers” onboard the Boeing 777-300ER aircraft that was heading from London to Singapore, the TSIB said in a press statement on Wednesday about the chronology of events compiled on the basis of data from flight data recorder and cockpit voice recorder.
Also read: Why was Singapore flight turbulence severe? | Explained
A 73-year-old passenger on the plane died after suffering a suspected heart attack on May 21, and 71 others were injured after the aircraft encountered turbulence over Myanmar forcing the pilots to divert the plane to Bangkok’s Suvarnabhumi International Airport.
The early findings show that at 07:49:21 hour (UTC) on May 21, 2024, as the aircraft was passing over the south of Myanmar at 37,000 feet and likely flying over an area of developing convective activity it first began to experience slight vibration due to fluctuations in the gravitational force or vertical acceleration.
Around the same time, there was an unexpected increase in aircraft altitude reaching a peak of 37, 362 feet and a sudden increase in airspeed due to an updraft (upward movement of air). This is when the pilots switched the seatbelt sign on.
Less than 20 seconds later, there were rapid changes in G over the 4.6 second duration resulting in an altitude drop of 178 feet, from 37,362 feet to 37,184 feet. “This sequence of events likely caused the injuries to the crew and passengers,” the press statement said.
The Singapore Airlines said it acknowledges the TSIB findings and was “fully cooperating with the relevant authorities in the ongoing investigations into this incident”.
The investigation team comprises of the Transport Safety Investigation Bureau of Singapore (TSIB), and United States representatives from the National Transportation Safety Board (NTSB), Federal Aviation Administration (FAA), and Boeing.
