On 5 August 2010, the crew of a Fairchild Industries Inc. SA227-AC aircraft, registered VH-TAG, were cleared for a visual approach to runway 30 at Williamtown aerodrome, New South Wales (NSW) by air traffic control  (ATC). The flight was a scheduled passenger service from Canberra, Australian Capital Territory (ACT), with two crew and 18 passengers onboard.

After landing, the crew was instructed by ATC to taxi to holding point Alpha, runway 30. During the taxi, the crew received an amended clearance to taxi to holding point Bravo, runway 30.

On approaching holding point Bravo, the crew checked the runway for other aircraft and taxied beyond the holding point. The crew was instructed by ATC to hold short of runway 30. The crew immediately stopped the aircraft and advised ATC that the aircraft had crossed the holding point, but was about 5 m away from the edge of the runway.

Shortly after, the crew observed a Boeing F/A-18 Hornet aircraft takeoff. About 10 seconds later a second Boeing F/A-18 Hornet took off on runway 30.

The crew discussed the incident and determined that they had not received a clearance to cross runway 30.

This incident highlights the importance of pilots utilising all of their available resources to confirm if the appropriate clearance has been received from ATC. Furthermore, if there is some doubt as to the location of other aircraft operating in the area, contact ATC or the pilot of the other aircraft to establish their position.