Source : THE AGE NEWS
Jetstar has confirmed that its planes are flying normally again after a mystery glitch related to the global positioning system (GPS) forced delays and cancellations last week.
Two flights from Australia to Bali were cancelled last week, and others were delayed, after faults in the GPS on Jetstar Airbus A320 Neos and A321 Neos prevented the flights from taking off.
The airline said it understood “the fault message was caused by a satellite signal issue” that occurred from May 21 to May 23 AEST.
A mystery glitch halted some Jetstar flights last week. Credit: Kate Geraghty
“Currently, this fault is not reoccurring. We continue to monitor closely,” a Jetstar spokesperson said.
GPS, a much-used navigation tool, determines a position by measuring proximity to an array of satellites in orbit. The equipment relies on several satellites to make a location reading.
Qantas-owned Jetstar said signals sent from the satellites were creating a fault message onboard the planes, which required the systems to be reset, delaying flights or forcing their cancellation.
Airbus, the planes’ manufacturer, told this masthead: “We understand that the fault messages on the aircraft were caused by a satellite signal issue.”
Aircraft navigation systems have numerous GPS units that receive data from different satellite constellations, Airbus said, noting that planes also have inertial reference systems and radio navigation aids.
These overlapping systems provide “redundancy in the event of an anomaly in-flight”.
“If a GPS anomaly is detected on the ground, it is standard operating procedure to check and reset the system before the next flight,” the Toulouse-based aircraft manufacturer said.
Whatever happened on the satellite side remains a mystery, though, with experts uncertain how a change to a satellite could cause faults with the GPS unit called ADS-B. It was also unclear if this glitch could affect Jetstar’s plane again.
An industry official with some knowledge of the situation said: “All is well that, for now, ends well.
“It looks like a satellite software update may have caused the problem. That was rolled back, and the aircraft systems have worked normally since.”
The GPS fault also caused delays on Jetstar flights to Bali, Fiji and Hobart from Australia’s east coast on Thursday. No other Qantas-owned aircraft were affected by the faults.
A spokesperson for Virgin Australia said last week that no similar issues had been reported with its aircraft. It’s understood that had the problem not been resolved, Jetstar would have had to apply for an exemption from the Civil Aviation Safety Authority. That proved unnecessary.
The Civil Aviation Safety Authority has been contacted for comment.
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