TWO packed Qantas jets came within 250m of a mid-air collision last week, according to an incident report.
A QantasLink Boeing 717 with 115 passengers was approaching Darwin International Airport last Tuesday when an RAAF air traffic controller inadvertently put it on a collision course with a Qantas Boeing 737-838 carrying 155 passengers which had taken off minutes earlier.
During a hair-raising moment, the collision avoidance system on board the Boeing 717, en route from Alice Springs, warned the pilots that the other plane was 800ft (250m) beneath them.
But Captain Robert Flipo chillingly wrote that "it must have got a lot closer than that".
According to a source familiar with the near miss, after the Melbourne-bound 737 took off from runway 29 shortly after 1.30pm the RAAF's Australian Defence Air Traffic System mistakenly assigned the tag for the plane to one of its Hercules C-130 aircraft flying through the control tower's airspace.
This meant air traffic controllers were not able to see the plane's identity, speed or height. Compounding the problem, an air traffic controller then allegedly confused the inbound 717 with the Hercules before accidently setting it on a collision course.
"We had been given a series of apparently non-sensical (sic) clearances both lateral and vertical," Captain Flipo wrote in a report. "We asked several times as to the intentions of ATC, e.g. what approach/track miles to expect, but received non-conclusive response."
After clearing the aircraft to land on runway 29 an air traffic controller cleared the plane to descend to 7000ft, he said.
The first officer, Andrew Field-Dodgson, was about to recommence descent when he spotted the other plane.
"It passed directly below us. I saw the traffic collision avoidance system display traffic 800ft (250m) below, and now descending at over 500ft per min," Mr Flipo said.
Darwin Airport is a shared public and military facility, and the RAAF is responsible for air traffic control.
A Defence spokesman said an air traffic controller had been suspended and there would be an investigation..
"An initial Defence investigation indicates that an Air Traffic Controller inadvertently directed an arriving and a departing aircraft on a path that would have taken the aircraft through the same height," he said.
The Australian Transport Safety Bureau is investigating the incident and a Qantas spokeswoman said as the matter was under investigation they were unable to comment
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Jets put on the path to disaster | News.com.au