Breakdown of separation, 157 km east of Darwin, Northern Territory, on 19 April 2007, VH-AZJ, Piper PA-31 and VH-TFF, Cessna 210N

On 19 April 2007, the Darwin radar (DNR) airspace was being operated as a non-radar procedural sector due to the removal of the Australian Defence Air Traffic System (ADATS) radar data from the civil Australian Advanced Air Traffic System (TAAATS). That change in arrangements was necessary because of ongoing technical problems with the integration of the ADF data into the civil radar system.

At about 0909 Central Standard Time, the DNR controller identified that an instrument flight rules (IFR) Cessna Aircraft Company C210N, tracking from Darwin to Gove, NT at an altitude of 9,000 ft, was in conflict with an IFR Piper Aircraft Corporation PA31-350 that was tracking from Bathurst Island to Jabiru and that a breakdown of separation standards had occurred. The controller re-established the required separation.

The investigation identified that the safety management system employed by Airservices Australia did not require the conduct of an independent review of the locally conducted hazard assessment process that was utilised to manage the controller's loss of radar surveillance capabilities. This was considered to be a safety issue.