SYDNEY: Navigation system problems near a military installation in Western Australia forced a Qantas flight to be aborted on Saturday.

Qantas says the flight, heading for Singapore with 277 passengers, returned to Perth soon after taking off, reports the Sydney Morning Herald.

A cockpit alert regarding the plane's navigation system alerted the pilots near Carnarvon, where there is a satellite-tracking station. The incident has raised fresh questions about electrical interference by signals from the radio dish (in October, a Qantas Airbus A330-300 from Singapore to Perth dropped twice, injuring 74 passengers).

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

Australian Transport Safety Bureau's director of aviation safety investigation Julian Walsh said analysis of flight data had revealed a failure of the plane's air data inertial reference unit, which supplies data on air pressure, temperature and acceleration. This resulted in wrong data being sent to the flight control system, which has a key role in flying the aircraft even with pilots in control.