AVIATOR Dick Smith has urged the federal Government to warn pilots that a GPS unit used in a fatal crash near Benalla, Victoria, in 2004 can default to the "dead reckoning", or simulator mode, if there is a problem with the aerial.
Mr. Smith said this was contrary to Australian Transport Safety Bureau findings that the GPS unit needed manual inputs for it to fly in the dead reckoning mode.
"An experienced professional pilot, John Chew, has found that this is completely wrong," he said in a letter to Transport Minister Anthony Albanese. "In fact, the GPS will fly a complete approach in the dead reckoning mode, which (depending on the wind) will replicate exactly the approach made by the accident aircraft."
Evidence given at an inquest into the crash last week suggested pilot Kerry Endicott was led by a malfunctioning GPS system to believe he was about to land at an airport when he crashed into a tree-lined ridge in heavy fog. Endicott, who died along with his five passengers, was also not warned by aircraft controllers he was about 30km off course.
Timber company director Robert Henderson, his daughter Jacquie, her husband and RAAF helicopter pilot Alan Stark, friend Belinda Andrews and Qantas jumbo jet pilot Geoff Brockie were killed in the July 28 crash.
Coroner Paresa Spanos heard it was likely that the satellite signals to the twin-engine plane's GPS had failed and the system went into "dead reckoning" and would have informed the pilot he was on course to land safely just before he crashed.
Counsel assisting the coroner, John Langmead, told the court Endicott received "erroneous information" from his GPS but he should have also seen warnings from the system that it had lost satellite signals.
The court heard the pilot had been flying off course since leaving Sydney's Bankstown Airport earlier that morning and air traffic controllers were notified of this divergence through a Route Adherence Monitoring alert system.
But air traffic controllers failed to notify Endicott he was off course on the second and third of three occasions the alarm was set off during the flight.
The Henderson family disputes assertions that Endicott would ignore warnings from a malfunctioning GPS and believes the inquiry should focus on the role of the air traffic controllers.
Mr Smith, who was prevented from giving evidence, acknowledged that Airservices Australia had taken steps to issue an alert when an aircraft strayed from its track by a particular tolerance.
But he said it had still not fixed "the vertical problem", when an aircraft descended from controlled to uncontrolled airspace below the lowest safe altitude.
He said his experience with the Australian Advanced Australia Air Traffic System was that its software could be modified to give controllers an alarm when an aircraft descended below a safe altitude.
http://www.theaustralian.news.com.au/story/0,25197,24181481-23349,00.html
Fonte: Flight Safety Information 19/08/2008.
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