Singapore Airlines (SIA) Flight SQ321, which was rocked by severe turbulence on Tuesday, climbed and descended violently twice in 62 seconds, startling passengers and one of them dying of a heart attack as the plane flew over Myanmar’s Irrawaddy Delta region – emerged on Saturday.
One passenger – 73-year-old Briton Geoffrey Kitchen – died and dozens of people were injured in the accident. This is SIA’s first fatal aircraft accident since the SQ006 crash in Taiwan in October 2000.
Because a plane bound for Singapore from London encountered sudden, severe turbulence over the Irrawaddy Basin while serving breakfast, the pilot declared a medical emergency and diverted the plane with 211 passengers and 18 crew to Bangkok’s Suvarnabhumi Airport, where the plane made an emergency landing at 3:45 p.m. ( 16:45 Singapore time).
Detailed flight data from flight tracking site Flightradar24 shows the Boeing 777-300ER climbed and descended rapidly twice in 62 seconds, starting at 3:49 p.m. Singapore time, as the plane neared the end of its nonstop flight from London to Singapore, the newspaper reported The Straits Times.
During this time, the aircraft climbed from a cruising altitude of 37,000 feet to 37,400 feet, then descended to 36,975 feet before returning to its cruising altitude.
This means that it was the rapid transition between climb and descent caused by turbulence – and not the change in altitude itself, which was relatively petite – that caused pandemonium in the cabin.
The Flightradar24 data – from a global network of ground-based receivers, satellites and radars receiving flight data from aircraft transponders – contradicts some earlier reports that indicated the plane fell from 37,000 feet to 31,000 feet between 4:06 p.m. and 4:10 p.m. cause of injury.
The report cited a commercial pilot who had flown both civilian and military multi-engine airliners for more than 20 years, most likely to assess the situation before heading to Bangkok. years.
The pilot said on condition of anonymity that the rapid climb would have created positive g-forces on the passengers, causing seated passengers to feel as if they were pinned in their seats.
The subsequent rapid descent would create negative g-forces that would throw unfastened passengers and other loose objects upwards onto the cabin ceiling, he added.
The involved aircraft went through another cycle of rapid climb and descent, causing more damage and injuries, with some passengers and objects hitting roof panels and overhead bins before being thrown back down.
This is reflected in the accounts of passengers aboard SQ321 who reported being thrown onto the roof of the cabin, with Australian passenger Teandra Tukhunen testifying that she was suddenly woken up as it was thrown onto the roof and then onto the floor.
G-force data would be recorded by a quick access recorder mounted on the aircraft. It is a flight data recorder designed to provide quick and simple access to raw flight data via means such as USB or mobile networks.
Flightradar24 data showed that the Boeing 777 first achieved a climb rate of 1,664 feet per minute (fpm), or 507 meters per minute, or twice the speed of the 52-story Capital Tower, and then descended six seconds later at a rate of 1,536 feet per minute. Just three seconds later, he quickly returned to a climb rate of 900 feet per minute, and after another 10 seconds he descended at a rate of 1,536 feet per minute.
Transport Minister Chee Hong Tat said on Friday that investigators from the Singapore Transport Safety Investigation Bureau were analyzing data from the cockpit voice recorder and flight data recorder.
Data from the U.S. National Transportation Safety Board from 2009 to 2018 showed that passengers injured in turbulence-related crashes were most likely to apply, wait for, or go to or from the restroom. The second most common group were passengers who were seated but not wearing seat belts.
