THE Qantas jet that rapidly lost altitude last week, resulting in and injured 74 passengers being injured, was being piloted manually on "erratic and erroneous" information, air transport investigators said last night.
The Australian Transport Safety Bureau's director of aviation safety investigation, Julian Walsh, told a press conference that a component responsible for supplying data on information such as air pressure temperature and acceleration had failed.
The air data computer - or inertial reference system - for the Airbus A330-300 was sending erroneous information to the flight control computer.
"Because of the fault … it has indicated to the flight control computer that the angle of attack of the aircraft was higher," Mr Walsh said.
"So the flight computer has considered that it needed to nose the aircraft over."
Last Tuesday, 303 passengers and 10 crew were rocked when the Airbus A330-300 flight from Singapore to Perth dropped twice from a height of 37,000 feet.
For 20 seconds, the passenger jet dropped nose-first for 650 feet. The aircraft levelled out momentarily before plunging another 400 feet in 16 seconds, the black box flight recorder showed.
The plane made an emergency landing at Learmonth air force base, north of Perth.
Passengers slammed into the ceiling and walls, causing serious injury in 14 people, who were treated for broken bones, concussion and severe lacerations.
Speculation about what caused the sudden plunge has been rife.
Late last week, investigators said that they were focusing on the aircraft's on-board computers, including the autopilot and flight control systems, as the cause of the incident, quashing suggestions that electronic interference from laptop computers had been to blame.
Mr Walsh said that during the course of the incident the aircraft's autopilot system had disconnected. Airbus is issuing a memo to all its pilots worldwide advising how to mitigate risks should a similar mishap occur. No similar incident had previously occurred on a Airbus.
The faulty component, manufactured by a US company, Northrop Grummann, is fitted in Airbus A330-300s, A330-200s and A340s, as well as non-Airbus aircraft.
Mr Walsh said a preliminary report by the bureau would be released one month from the date of the flight.
Last night a spokeswoman for Qantas said it could not comment on the safety bureau's findings until a final report was released. The airline was assisting in the formal investigation and conducting its own separate probe.
Qantas has agreed to compensate each affected passenger, judging cases individually. Flights would be refunded and all passengers would receive a voucher to the value of a return flight to London, the airline said.
That would be valued between $2500 and $6000, depending on whether the passenger had been in business class or economy. Legal experts say Qantas could face a string of compensation claims running into the millions, with passengers suffering serious injuries in the incident entitled to claim up to $500,000 each under Australian law.
Those from other countries in Europe and Asia on the flight could claim considerably more because they come from countries where the Montreal Convention on passengers compensation has been passed into law.
Email a friend
Favourites
Del.icio.us
Facebook
Digg
StumbleUpon
MySpace
Reddit
Newsvine
LinkedIn
Kwoff
Twitter