Two airliners were just seconds away from a mid-air, head-on collision at night over a remote part of Australia due to botched air traffic control, the Australian Transport Safety Bureau has found.
A Cathay Pacific Airbus A330 and a Virgin Blue Boeing 737 were flying towards each other at the same altitude and on the same flight path 222 kilometres north-west of Tennant Creek, in the Northern Territory, on December 22, 2009, when the automatic collision warning alarms sounded in the planes’ cockpits.
At 2.52am the planes were fast closing on one another and were about 120 seconds from hitting, investigators found.
The safety investigators describe the likelihood of a head on collision as ‘‘imminent’’.
Air traffic personnel responsible for earlier airspace separately communicated the two planes’ flight paths and altitudes an hour earlier to the controller as the planes entered the common space, but for an hour he didn’t twig the airliners were heading for each other.
The on-duty air traffic controller, an former air force tower controller who’d been given a shortened conversion course, did not recognise the planes were both flying at 37,000 feet on a collision course.
The first moment he was alerted was when the Cathay pilots radioed in to question what other approaching traffic was in the airspace that triggered their collision warning alarm.
The pilots radioed a second time.
Thirty seconds later he told the Cathay pilots to climb 1000 feet, but failed to issue a safety alert as required.
The pilots did so, but the planes had closed in another 9km.
But then both Cathay and Virgin pilots took matters into their own hands, each banking right to spear off in opposite directions, to further get out of each other’s way.
‘‘The flight crews of both aircraft reported that they considered the situation to be significant enough to commence diversions right of track without obtaining an air traffic control clearance prior to their respective manoeuvres,’’ investigators noted.
A supervisor on night duty was preoccupied with another matter when the near miss occurred.
Investigators found the controller had joined Airservices Australia little more than a year earlier, and the organisation exempted the controller from 33 weeks of a 44 week training course after granting ‘‘recognition for prior learning’’ as a consequence of having worked as a controller in the air force.
The controller was not given training on how to resolve impending collision courses.
But trainers found a number of skill deficiencies, including ‘‘ineffective conflict recognition, particularly in relation to opposite direct traffic, and inadequate scanning’’.
He was later retrained and given the tick just three days before the incident, raising awkward matters for Airservices Australia to answer.
The controller failed to comprehend how critical the situation was, investigators found.
‘‘The incident demonstrated a less-than-effective recovery action by the controller,’’ investigators concluded.
Airservices Australia came in for criticism over its abridged training, which was a ‘‘significant safety issue’’.
‘‘As the controller had not received training in compromised separation recovery techniques, he was inadequately equipped to manage the imminent conflict,’’ investigators determined.
Airservices Australia launched its own investigation, made 11 findings and has taken steps to fix the problems identified, but not all actions have yet been implemented.
A Cathay Pacific Airbus A330 and a Virgin Blue Boeing 737 were flying towards each other at the same altitude and on the same flight path 222 kilometres north-west of Tennant Creek, in the Northern Territory, on December 22, 2009, when the automatic collision warning alarms sounded in the planes’ cockpits.
At 2.52am the planes were fast closing on one another and were about 120 seconds from hitting, investigators found.
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‘‘The aircraft were 29.5 nautical miles (55 km) and about two minutes flight time apart at that time,’’ investigators determined.The safety investigators describe the likelihood of a head on collision as ‘‘imminent’’.
Air traffic personnel responsible for earlier airspace separately communicated the two planes’ flight paths and altitudes an hour earlier to the controller as the planes entered the common space, but for an hour he didn’t twig the airliners were heading for each other.
The on-duty air traffic controller, an former air force tower controller who’d been given a shortened conversion course, did not recognise the planes were both flying at 37,000 feet on a collision course.
The first moment he was alerted was when the Cathay pilots radioed in to question what other approaching traffic was in the airspace that triggered their collision warning alarm.
The pilots radioed a second time.
Thirty seconds later he told the Cathay pilots to climb 1000 feet, but failed to issue a safety alert as required.
The pilots did so, but the planes had closed in another 9km.
But then both Cathay and Virgin pilots took matters into their own hands, each banking right to spear off in opposite directions, to further get out of each other’s way.
‘‘The flight crews of both aircraft reported that they considered the situation to be significant enough to commence diversions right of track without obtaining an air traffic control clearance prior to their respective manoeuvres,’’ investigators noted.
A supervisor on night duty was preoccupied with another matter when the near miss occurred.
Investigators found the controller had joined Airservices Australia little more than a year earlier, and the organisation exempted the controller from 33 weeks of a 44 week training course after granting ‘‘recognition for prior learning’’ as a consequence of having worked as a controller in the air force.
The controller was not given training on how to resolve impending collision courses.
But trainers found a number of skill deficiencies, including ‘‘ineffective conflict recognition, particularly in relation to opposite direct traffic, and inadequate scanning’’.
He was later retrained and given the tick just three days before the incident, raising awkward matters for Airservices Australia to answer.
The controller failed to comprehend how critical the situation was, investigators found.
‘‘The incident demonstrated a less-than-effective recovery action by the controller,’’ investigators concluded.
Airservices Australia came in for criticism over its abridged training, which was a ‘‘significant safety issue’’.
‘‘As the controller had not received training in compromised separation recovery techniques, he was inadequately equipped to manage the imminent conflict,’’ investigators determined.
Airservices Australia launched its own investigation, made 11 findings and has taken steps to fix the problems identified, but not all actions have yet been implemented.
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