Rattled travellers and crew landed in Singapore on Wednesday after a terrifying high-altitude plunge on a flight from London during which an elderly British passenger, identified as Geoffrey Kitchen (73), died and more than 80 were injured.
Singapore Airlines flight SQ321 hit "sudden extreme turbulence" over Myanmar 10 hours into its journey on Tuesday, abruptly rising and plunging several times.
One passenger said people were thrown around the cabin so violently they put dents in the ceiling during the drama at 11,300 metres (37,000 feet), leaving dozens with head injuries.
Photos from inside the plane show the cabin in chaos, strewn with food, drinks bottles and luggage, and with oxygen masks dangling from the ceiling.
Singapore Airlines chief executive Goh Choon Phong said Wednesday the carrier is "very sorry for the traumatic experience" endured by those on board.
"On behalf of Singapore Airlines, I would like to express my deepest condolences to the family and loved ones of the deceased," he said in a video statement.
SIA is fully cooperating with the relevant authorities in probing this incident, he added.
Officers from Singapore's Transport Safety Investigation Bureau arrived in Bangkok on Tuesday night, Singapore's Transport Minister Chee Hong Tat said in a statement on Facebook.
As the incident involves a U.S. company, Boeing, which makes the 777-300ER aircraft, the U.S. National Transportation Safety Board (NTSB) was sending an accredited representative and four technical advisers to support the investigation, he said.
The plane, carrying 211 passengers and 18 crew, made an emergency landing at Bangkok's Suvarnabhumi Airport, where medical staff used gurneys to ferry the injured to ambulances waiting on the tarmac.
Bangkok's Samitivej Srinakarin Hospital said late Tuesday that 71 people had been sent for treatment - six of them seriously injured.
The airport in the Thai capital said 83 passengers and crew were hurt.
A Thai Airways employee told AFP he saw "more than 10" ambulances rushing to the scene.
Airport staff separated passengers into four groups based on their medical condition, said the airline employee, who gave only his first name Poonyaphat.
A relief flight carrying 131 passengers and 12 crew landed at Singapore's Changi Airport on Wednesday morning.
Relieved relatives greeted the arrivals with hugs, but all were too shaken to talk to waiting reporters.
Andrew Davies, a British passenger aboard the Boeing 777-300ER, told BBC radio that the plane "suddenly dropped" and there was "very little warning".
"During the few seconds of the plane dropping, there was an awful screaming and what sounded like a thud," he said, adding that he helped a woman who was "screaming in agony" with a "gash on her head".
Separately, he told a BBC podcast he feared the plane was going to crash.
"Remembering the plane now -- the huge dents in the roof that people had obviously hit with their head. There was a water bottle stuck in a gap in the ceiling," he said.
'Crazy flight'
Singapore Prime Minister Lawrence Wong sent his "deepest condolences" to the family and loved ones of Geoff Kitchen, a musical theatre director from near Bristol.
The city-state is sending investigators to Bangkok to probe the incident and Wong posted on Facebook that they were "working closely with Thai authorities."
Of the passengers, 56 were Australians, 47 were British, 41 were Singaporeans, and three Indians according to the airline.
Malaysia's foreign ministry said nine of its nationals were hospitalised, including one in a critical but stable condition.
An AFP photographer saw people in Singapore Airlines yellow vests entering the plane on Wednesday as it remained grounded in Bangkok.
"In terms of exactly what happened, it's too early to tell. But I think passengers are too casual on board commercial aircraft," US-based aerospace safety expert Anthony Brickhouse told AFP.
"The moment the captain turns off the seatbelt sign, people literally unbuckle."
Davies, the passenger, said "the plane suddenly dropped" at the very moment a seatbelt sign came on.
Allison Barker told the BBC her son Josh, who was aboard the plane, texted her that he was on "a crazy flight" that was making an emergency landing.
"It was terrifying," she said. "I didn't know what was going on. We didn't know whether he'd survived, it was so nerve-racking. It was the longest two hours of my life."
Weather forecasting service AccuWeather on Tuesday said rapidly developing, explosive thunderstorms near the flight path of Flight 321 most likely contributed to violent turbulence.
"Developing thunderstorms often have strong updrafts, a zone of upward moving air, that rises very rapidly, sometimes at more than 100 mph, and can leave pilots will little time to react if it occurs directly in front of the plane," said Dan DePodwin, AccuWeather’s Senior Director of Forecasting Operations.
Scientists have long warned that climate change is likely to increase so-called clear air turbulence, which is invisible to radar.
A 2023 study found the annual duration of clear air turbulence increased by 17 percent from 1979 to 2020, with the most severe cases increasing by more than 50 per cent.
Sara Nelson, international president of the Association of Flight Attendants-CWA, representing over 50,000 workers at 20 airlines, said it is important for passengers to wear seatbelts whenever seated.
"It is a matter of life and death," Nelson said. (Agencies)
Bob Blackman MP speaks during the event