FIFTEEN passengers were injured on a Qantas flight from Melbourne to Hong Kong after a serious stall alert last Friday, it has emerged.

Authorities will begin a serious incident investigation after a ‘stick shaker’ warning activated on the QF29 service on April 7.

Stick shaker is an industry phrase used to describe a stall warning, where the controls shake to warn the flight deck of an imminent stall.

Details of the in-flight incident, which took place at the end of the Boeing 747’s 9.5 hour flight, some 110 kilometres south of Hong Kong, have only just emerged.

The Australian reports that the plane also experienced airframe buffeting, which often causes vibration.

“The flight crew disconnected the autopilot and manoeuvred the aircraft in response,” the Australian Transportation Safety Bureau (ATSB) told the newspaper in a statement.

“Fifteen passengers received minor injuries. As part of the investigation, the ATSB will interview the flight crew and gather additional information.”

One of the 15 people to be injured required hospitalisation but was later released, it was reported.

The airline confirmed the incident to The Australian on Wednesday — the first public statement almost a week later.

“Customers on QF29 experienced unexpected in-flight turbulence when travelling from Melbourne to Hong Kong on Sunday,” a Qantas spokeswoman said.

“We notified the ATSB of the occurrence, and our own teams are also reviewing the event.”

Geoffrey Thomas, an aviation expert, told The Australian that such an incident was “extremely unusual”.

“A stick shaker is an extremely rare event, and very, very serious,” he said.

David Adams, aviation solicitor with Shine Lawyers, advised that injured passengers would be entitled to make a compensation claim for physical and mental injuries arising from the incident.

“The international Qantas flight QF29 flying from Australia and Hong Kong on 7 April involved two nations who are signatories to the Montreal Convention 1999. Under the Convention ... QANTAS will be held strictly liable in circumstances where the event is considered an ‘accident’,” he said.

“The injuries sustained by the 15 passengers were most likely caused by ‘severe turbulence’ or by pilot error in invoking an imminent stall according to present reports. Both of these scenarios can be considered to be ‘accidents’ within the meaning of the Montreal Convention 1999 and QANTAS will be held strictly liable by a court,” Mr Adams said.

“This is reinforced by QANTAS’ statement that the in-flight turbulence was ‘unexpected’, which is one element required to show that an accident has occurred.”

“It is an unfortunate event to suffer injuries on board an aircraft, but the Montreal Convention 1999 operates to compensate passengers who have suffered injuries in the care of airlines.”