SIA passengers on the May 21 London-Singapore aircraft experienced intense turbulence for 62 seconds

Seen flying over the Irrawaddy Delta area of Myanmar on Saturday, Singapore Airlines (SIA) Flight SQ321, which was rocked by strong turbulence on Tuesday, rose and fell quickly twice in 62 seconds, shocking the passengers and killing one of them with a heart attack.

Geoffrey Kitchen, a 73-year-old British passenger, lost his life in the accident, while several others were hurt. Since the SQ006 disaster in Taiwan in October 2000, this is the first aircraft accident with a death in the SIA.

The pilot of the aircraft, which was carrying 211 passengers and 18 crew members, declared a medical emergency and diverted the aircraft to Bangkok’s Suvarnabhumi Airport, where it made an emergency landing at 3:45 p.m. (4:45 p.m. Singapore time), as the flight, which was traveling to Singapore from London, experienced sudden severe turbulence during the breakfast service.

The Boeing 777-300ER rapidly climbed and descended twice in 62 seconds, beginning at 3:49 pm Singapore time, according to granular flight data from flight tracking website Flightradar24. The incident occurred as the plane was approaching the end of a non-stop flight from London to Singapore, according to The Straits Times newspaper.

The aircraft rose to 37,400 feet during this period, descended to 36,975 feet, and then returned to its cruising altitude of 37,000 feet.

This suggests that the chaos within the cabin was caused by the turbulence’s quick transition between the rise and fall, rather than the relatively small altitude difference.

The data from Flightradar24, which is sourced from a global network of satellites, ground-based receivers, and radars that receive flight data from aircraft transponders, defies some previous reports that linked the injuries to the aircraft’s descent from 37,000 feet to 31,000 feet between 4.06 and 4.10 p.m.

According to the broadsheet report citing a commercial pilot who has flown both civil and military multi-engine passenger aircraft for more than 20 years, this latter transition appears to be the pilots performing a controlled descent, most likely to assess the situation before diverting to Bangkok.

The pilot, who requested anonymity, said that the quick ascent would have given passengers positive G-forces, making seated passengers feel as if they were being glued to their seats.

He said that the ensuing fast fall would have produced negative G-forces, which would have sent unrestrained passengers and other loose objects upward into the cabin roof.

The troubled aircraft had yet another round of abrupt ascents and descents, resulting in further harm and casualties. A number of people and items struck the overhead lockers and roof panels before the aircraft was sent back down.

The experiences of passengers on board SQ321 who claimed to have been tossed onto the cabin roof corroborate this; Australian passenger Teandra Tukhunen narrated how she was suddenly awakened up and flung both to the floor and the top.

The fast access recorder installed on the aircraft would have recorded the G-force data. This flight data recorder is intended to make it simple and fast to obtain unprocessed flight data via USB or cell phone networks.

The Boeing 777 initially reached a rise rate of 1,664 feet per minute (fpm), or 507 meters per minute, twice the height of the 52-story Capital Tower, according to the Flightradar24 data. Six seconds later, the aircraft descended at 1,536 fpm. In only three seconds, it was back to climbing at 900 fpm, and ten seconds later, it was falling at 1,536 fpm.

On Friday, Singapore’s Transport Safety Investigation Bureau investigators, according to Transport Minister Chee Hong Tat, were reviewing data from the flight data recorder and the cockpit voice recorder.

According to statistics from the US National Transportation Safety Board, between 2009 and 2018, the majority of passengers injured in turbulence-related crashes were either walking, waiting for, or using the restroom. The second most frequent category consisted of seated but unbuckled individuals.