VH-TJM departed Ayers Rock for Alice Springs and VH-LTC departed Alice Springs for Ayers Rock. To ensure separation the Alice Springs air traffic controller assigned a cruising altitude of 5000 feet to VH-LTC and cleared VH-TJM to descend to 7000 ft. He estimated that the aircraft would pass about 40km from Alice Springs and VH-LTC was instructed to report sighting and passing VH-TJM.
Subsequently, at 48km from Alice Springs, VH-TJM was cleared for a visual descent. The air traffic control workload was heavy at the time, but shortly afterwards the controller realised he had not applied a separation standard before allowing VH-TJM to commence the visual descent. He contacted both aircraft for position reports which revealed that they had passed safely and were about 20km apart. Fortuitously there was no confliction.
