Call for no-go zone after another Qantas forced landing

[Kieran Wells]

Call for no-go zone after another Qantas forced landingJanuary 2, 2009 - 10:22AM
A Qantas jet was forced to abort its flight on Saturday following problems with its navigation system near a military installation in Western Australia.

Qantas said yesterday that flight QF71, bound for Singapore with 277 passengers, returned to Perth soon after taking off.

A cockpit alert said there was a problem with the plane's navigation system near Carnarvon.

The incident has raised fresh questions about whether electrical interference from signals is to blame.

In October, a Qantas Airbus A330-300 from Singapore to Perth dropped twice from a height of 37,000 feet, injuring 74 passengers.

The plunges - lasting 20 seconds and 16 seconds - sent passengers slamming into the cabin's ceiling and walls, causing serious injury in 14 people who were treated for broken bones, concussion and lacerations.

The plane made an emergency landing at Learmonth air force base, north of Perth.

Air transport investigators said the incident was caused by a faulty computer component that sent "erratic and erroneous information" to the plane's flight control system.

The Australian Transport Safety Bureau's director of aviation safety investigation, Julian Walsh, said analysis of flight data had revealed that the plane's air data inertial reference unit - the device responsible for supplying data on air pressure, temperature and acceleration - had failed.

As a result, wrong data was sent to the flight control system, which has a key role in flying the aircraft, even with pilots in control.

smh.com.au
http://www.smh.com.au/travel/call-fo...0102-78re.html