Breakdown of separation - Cessna 172, VH-WYG and Boeing 747, N171UA, 19km north-west Sydney Airport, New South Wales, on 7 August 2011

On 7 August 2011, a Cessna Aircraft 172, registered VH-WYG (WYG), departed Bankstown, New South Wales, for a student solo-navigation exercise. WYG entered Sydney controlled airspace without a clearance, which subsequently resulted in a breakdown of separation with a departing Boeing 747 aircraft, registered N171UA. Air Traffic Services (ATS) alerted the crew of N171UA to the traffic, and issued instructions for N171UA to conduct an avoidance turn away from WYG.

When the pilot of WYG contacted ATS for an airways clearance to conduct the Sydney Harbour scenic route, he was informed that he had been radar-identified as having entered controlled airspace without a clearance. The pilot then remained outside controlled airspace and subsequently elected to terminate the navigation exercise and return to Bankstown via the Lane of Entry.

The pilot reported that inclement weather had influenced his en-route track decision making during the flight.

This incident highlights the importance of both weather avoidance, and awareness of proximity to controlled airspace.