Australian feared death after Cathay Pacific flight plunged mid-air

An Australian passenger onboard a Cathay Pacific flight rocked by severe turbulence says he feared he was going to die after the aircraft suddenly plunged mid-air, throwing passengers and food carts around the cabin and injuring 10 people.

Flight CX156 was travelling from Brisbane to Hong Kong on Saturday, when the Airbus A350-900 dropped suddenly, about two hours before landing.

Cathay Pacific confirmed 10 people were injured during the incident, including six cabin crew and four passengers.

The airline said medical personnel boarded the aircraft after it landed safely in Hong Kong about 6:45am, local time.

Eight injured people were taken to nearby hospitals for treatment.

Cairns businessman Nicholas Stevenson was travelling on the flight when the "plane just dropped".

"There were phones flying, coffees smashed into the roof, food absolutely everywhere.

"People were screaming. There was a lot of people really freaking out."

Mr Stevenson said the turbulence struck without warning as cabin crew had just begun serving breakfast on the overnight flight.

"They'd turned the lights on, people were waking up, and they'd started giving out meals," he said.

"There was no seatbelt sign or warning beforehand."

He said the plane plunged twice in quick succession.

"The first one caught everyone completely off guard, and then probably 15 or 20 seconds later it happened again," he said.

"People who'd just managed to get back into their seats or grab onto something got thrown around again."

Mr Stevenson said the force of the turbulence launched unsecured passengers and objects into the air.

"Anyone that didn't have their belts on hit the roof," he said.

He said cabin crew appeared to suffer the worst injuries because they were standing in the aisles with heavy service carts when the aircraft dropped.

"The staff got hit pretty badly because not only were they thrown, but the food carts went flying into them as well," he said.

Mr Stevenson said passengers only realised the seriousness of the situation after calls went out across the cabin asking whether any doctors were on board.

"They started making announcements asking for doctors," he said.

"That's when we realised there were some pretty seriously injured people."

He said four doctors travelling on the flight assisted injured crew members and passengers while the aircraft continued towards Hong Kong.

"There wasn't really anywhere else to land," he said.

"They just treated people at the back of the plane while we kept flying."

Mr Stevenson said the pilot later apologised to passengers and explained the aircraft had encountered a weather system that appeared with little warning.

"The pilot said they believed it was some sort of thunder or lightning cell," he said.

"He said they didn't really see it on the radar until the last minute because it was dark."

He said medical help was waiting on the tarmac.

"When we landed, they told everyone to stay seated because the injured people had to get off first," Mr Stevenson said.

Despite the ordeal, Mr Stevenson said he was physically unharmed because he had kept his seatbelt fastened.

"I just remember thinking there's not much you can do in that situation," he said.

"My parents were both in the air force, and my dad always used to say if a plane's going down there's not really much you can do about it.

These types of incidents are usually investigated by authorities, including an analysis of flight and cockpit data.

Cathay Pacific says it is cooperating fully with authorities and is providing support to affected passengers and crew.