Two Qantas aircraft were involved in what the Australian Transport Safety Bureau is calling a "serious incident" over Sydney, according to the authority's preliminary report released today.
A trainee controller was working under the supervision of an on-the-job training instructor at the time of the event on August 5, 2019.
The crew of a Qantas Airbus A330-300 were cleared to take-off by air traffic control, while at the same time a Qantas Boeing 737-800 had been cleared to land and was on final approach to the same runway.
There are strict rules around aircraft separation:
- Air traffic controllers must keep aircraft separated vertically or horizontally. When the separation between two or more aircraft is less than the standard, there is a loss of separation
- When aircraft are operating inside terminal area airspace, such as Sydney, controllers must maintain a minimum separation between aircraft of 5km laterally or 300m vertically
Controllers assessed that there would be insufficient space between the aircraft taking off and the one landing, so instructed the landing aircraft to abort and perform a go-around.
Despite this move, the two aircraft came within 800m of each other laterally and 150m vertically.
The A330 flight crew received an alert from their aircraft's airborne collision avoidance system and then saw the 737 in close proximity. In response, they reduced the aircraft's course to avoid getting any closer to the 737.
The captain of the A330 made a radio transmission back to the controllers.
"That was very close," he said.
The A330 then continued on to Melbourne, and the 737 landed in Sydney moments later.