A dozen Australians remain in hospital after horror flight turbulence

A 73-year-old British man died from a suspected heart attack and more than 30 others were seriously injured as unsecured passengers and objects hurtled around the cabin.

Three Australians are in intensive care in Thailand and up to nine others remain in the hospital after the plane diverted to make an unscheduled landing in Bangkok at 6.45pm AEST on May 21.

Images and videos of the cabin show the aftermath of chaos on Singapore Airlines flight SQ321 with overhead panels broken, masks hanging from the ceiling and personal items strewn in the aisles.

One of the Australian passengers on a fatal Singapore Airlines flight says she was flung to the roof of the plane's cabin during a severe bout of turbulence.

Speaking from Samitivej Srinakarin Hospital in Thailand with her arm in a sling, Teandra Tukhumen described being among 56 Australians on board a flight from London that was forced to make an emergency landing in Bangkok.

"I was asleep and then I was woken up because I was thrown to the roof and then the floor," she told Sky News UK.

"It was just so quick, they had no warning whatsoever.

"The pilot saved our lives - we're alive - so that's all that matters in the end."

Although the crew had turned on the seatbelt sign, Ms Tukhumen said she was flung from her seat before she could comply.

Bangkok Suvarnabhumi airport general manager Kittipong Kittikachorn said on May 21 seven people were in a critical condition while 23 people, including a flight attendant, were receiving treatment for serious injuries.

There were nine people being treated for minor wounds and a further 16 with minimal injuries.

British passenger Andrew Davies said a member of the Singapore Airlines crew told him the turbulence "was by far the worst in her 30 years of flying".

He described the scene with belongings scattered across the plane and coffee splattered on the ceiling as "surreal".

"So many injured people. head lacerations, bleeding ears. A lady was screaming in pain with a bad back. I couldn't help her, just got her water," he said in a post to X.

Singapore Airlines said 56 Australian and 23 New Zealand passengers were on board the flight among 211 total passengers and 18 staff when they experienced "sudden extreme turbulence" at 37,000 feet over Myanmar's Irrawaddy Basin.

Consular officials from the Australian Embassy in Bangkok have provided assistance to eight Australians taken to hospital in Bangkok, a Department of Foreign Affairs and Trade spokesperson said on May 22.

"The Australian Embassy in Bangkok and the Australian High Commission in Singapore continue to make inquiries to confirm if any further Australians are affected," the spokesperson said.

Home Affairs Minister Clare O'Neil said her thoughts were with those affected by the incident.

"This is a terrible experience that these people have gone through," she told Seven's Sunrise program on Wednesday.

"The Australian government will provide consular assistance wherever we can, wherever it's needed to those people.

"I know the embassy in Bangkok and the High Commission in Singapore are actively trying to contact those Australians at the moment ... we will do everything we can to help."

The man that died of a suspected heart attack, Geoff Kitchen, was remembered as "a gentleman with the utmost honesty and integrity" by his theatre group in South Gloucestershire.

"Our thoughts and prayers go out to his wife and the family at this difficult time, and we ask that you respect their privacy," the Thornbury Musical Theatre Group said.

Passenger Andrew Davies said he and others onboard helped Mr Kitchen as much as he could in the chaotic aftermath.

"Shouted for a defibrillator. Passengers with medical training helping as much as they could. CPR on the poor gentleman that passed," Mr Davies said in a post to X.

"Another passenger laid flat in aisle further behind me. Not sure what happened with them. Wish I could have helped more," he added.

Singapore Airlines CEO Goh Choon Phong said "I would like to express my deepest condolences to the family and loved ones of the deceased passenger."

"We also deeply apologise for the trauma experienced by all passengers and crew members on this flight," he said.

Singapore Airlines has transported 131 passengers and 12 crew members to Singapore, their intended destination, after the plane diverted to Bangkok.

A relief flight was organised to Singapore just after 7am AEST on May 22 and passengers with onward connections were rebooked on alternative flights, including back to Australia.

"Another 79 passengers and six crew members from SQ321 remain in Bangkok. This includes those receiving medical care, as well as their family members and loved ones who were on the flight," the airline said on the morning of May 22.

Australian International Pilots Association safety and technical director Captain Steve Cornell suspects the plane flew through clear air turbulence rather than anything caused by storms or intense weather systems.

Clear air turbulence is not visible on radar screens or from the cockpit and pilots rely on warnings from planes flying ahead to dodge these jet stream winds, he said.

Jet stream winds reach "upwards of 300 kilometres per hour and flow from west to east".

"Turbulence occurs where you get shifts in the velocity of those winds," he said.

"Descending 1000 or 2000 feet can see you clear of that turbulent air and back into smooth air still in the jet stream itself."

Captain Cornell said the pilots performed a "managed" descent during the turbulence.

"Having looked at the flight data, it looks like they descended about 6000 feet in five minutes," he said.

"That is a very moderate descent."

READ MORE: How flight SQ321 gave passengers the fright of their lives

But the turbulence was enough to cause chaos in the cabin while passengers were preparing to eat. One passenger said the seatbelt sign was switched on just moments before the turbulence began.

"This is when you get these kinds of injuries. People get thrown around the aircraft, into other people and into ceiling panels," the Boeing 737 captain said.

"Even if the seatbelt sign is turned off, I don't think it's an unnecessary burden just to have yours loosely fastened. It would prevent a lot of these injuries that we see," he said.

Australians in need of emergency consular assistance should contact the Australian Government's 24-hour Consular Emergency Centre on +61 2 6261 3305 (from overseas) or 1300 555 135 (from within Australia).

Family members and loved ones seeking information may contact the Singapore Airlines hotlines at +65 6542 3311 (Singapore), 1800-845-313 (Australia), and 080-0066-8194 (the United Kingdom).