Boeing 737-376, VH-TAI

Sydney airport and associated airspace was being operated in accordance with Mode 9 of the Long-Term Operating Plan. A Boeing 737 (B737) departed runway 34R for Melbourne and was cleared initially to 5,000 ft on a MARUB ONE standard instrument departure (SID), with a Wollongong transition. The SID required the crew to intercept and track via the 075 Sydney VOR radial to 15 NM (waypoint MARUB), and to then turn right and track 144 degrees until passing 9,000 ft.

At the same time, another B737 inbound to Sydney on a CHEZA THREE standard arrival route (STAR) for a landing on runway 34R had passed waypoint WHALE, located 20 NM east of Sydney, and was maintaining 7,000 ft in accordance with its clearance.

The Departures South controller cancelled the 5,000 ft altitude restriction for the departing B737 and issued a clearance for the aircraft to climb to Flight Level 280. The 5,000 ft restriction would have assured separation with the inbound B737. When the altitude restriction was removed, the controller relied on monitoring the flight paths of both aircraft and intervening, if necessary, to maintain separation.

When the departing B737 turned right to track 144 degrees in accordance with the SID, there was a breakdown in separation between the two aircraft. Separation was reduced to 2.5 NM horizontally and 500 ft vertically, whereas the required standard was either 3 NM or 1,000 ft. Traffic information was passed to the crew of the departing B737, who sighted the other B737 while passing behind it.

The Departures South controller was relatively inexperienced, having held a control rating in the Sydney Terminal Control Unit for only three weeks. The controller was distracted from the monitoring role by coordination activities with Bankstown control tower, and by radio transmissions to other aircraft. The controller also considered himself to have been fatigued as a result of local rostering practices.