Loss of separation — Airbus A330 and Boeing 737 near Sydney

Summary

A loss of radar separation occurred between a Virgin Australia Airbus A330 and a Qantas Boeing 737 in the Sydney Terminal Control Area. Both aircraft were given conflicting descent clearances by two separate sectors, resulting in a loss of the required 1,000 ft vertical separation standard. Minimum separation was 550 ft vertical. TCAS Resolution Advisories were triggered on both aircraft.

Investigation Findings (4)

1. 01Two ATC sectors issued simultaneous descent clearances that resulted in a geometry conflict.
2. 02Coordination procedures between sectors were not completed prior to the clearance being issued.
3. 03Both crews followed TCAS RA guidance and separation was restored.
4. 04Airservices Australia implemented additional coordination requirements for the affected sector boundary.