Ten passengers are recovering in hospital after they were injured when a Qantas Airbus A330 airliner was involved in a mid-air incident over Australia's north-west.

They were hurt when the passenger jet carrying 313 people experienced a "sudden change in altitude", forcing the pilot to make an emergency landing near Exmouth [at Learmonth RAAF airfield].

The Royal Flying Doctor Service said at least six of those hospitalised had suffered serious spinal injuries. A further 30 people suffered slight injuries.

Qantas Airbus Drama
© PerthNow.com / Kristin Anderson
Ordeal... A passenger from the downed A330 jet is admitted to Exmouth Hospital.
Inspector Wayne Silver, of WA Police, said preliminary information suggested there had been some sort of "instrument failure" and turbulence, forcing the emergency landing after a mayday call.

Emergency services and medical staff were at the airport.

The Australian Transport Safety Bureau said the pilot of the Qantas flight from Singapore to Perth declared an emergency after a mid-air 'upset'.

The incident apparently caused passengers to be flung around the cabin, breaking some passengers' bones.

Qantas confirmed that "a number of passengers and crew sustained injuries, including fractures and lacerations... following a sudden change in altitude."

Qantas said the flight was carrying 303 passengers and 10 crew. It landed at about 3.30pm local time - about 20 minutes ahead of its scheduled arrival in Perth.

Qantas said there were no details available as to what caused the altitude change.

Thousands of passengers worldwide have been injured by clear air turbulence, which weather radar cannot pick up. Planes hitting clear air turbulence can change altitude dramatically - with shocking consequences for passengers if they are not wearing their safety seat belt.

The emergency descent is the latest in a string of incidents that have tarnished the Qantas brand.

The worst occurred aboard a Boeing 747 which had to make an emergency landing on July 25 in Manilla when an oxygen bottle exploded through a floor and into the passenger cabin.

Since then the Australian carrier has been beset by turn-backs and mechanical problems prompting extra audits on its fleet by the Civil Aviation Safety Authority because of suspicions that some off-shore maintenance on planes may not meet standards.