Background
On 19 October 2022, a Boeing 737-8FE aircraft, registered VH-YFT and operated by Virgin Australia, departed Brisbane, Queensland on a scheduled passenger flight to Sydney, New South Wales. The flight was designated VA942.
The Incident
After the aircraft reached the top of descent, the crew contacted air traffic control (ATC) and received a clearance for a standard arrival to land on runway 34L at Sydney Airport. However, runway 16L was the operational runway at the time. When the crew transferred to Sydney Approach, they were instructed to expect runway 16L. This initially caused confusion between the crew and ATC, but the correct runway was established and the crew performed an independent visual approach to runway 16L.
Investigation Findings
The Australian Transport Safety Bureau (ATSB) found that an incorrect clearance was verbally communicated to VA942, which was not identified by the enroute air traffic controller or the crew during the read-back or hear-back process. The error likely occurred due to momentary interference of related, coinciding information about the assigned flight level (FL 340) and the runway (34L). The enroute controller reported that when the crew initially made contact and the standard terminal arrival route (STAR) was provided, runway 16L was selected from the available runways as intended. However, while looking at the flight level on the air situation display (ASD), the controller issued the clearance for 34L. This skill-based error most likely occurred because of the interference of information between FL 340 and 34L. The information entered into the air traffic management system was correct. Consequently, the approach controller identified and rectified the error with the crew of VA942 well before an undesirable state for landing had the opportunity to develop.
Safety Message
The ATSB noted that slips in verbal communication can occur at any time and can pose a threat to safe operations if the content is inaccurate and not identified during the read-back or hear-back process. Pilots and air traffic controllers are reminded to seek verification when there is confusion or a misunderstanding on any information in a clearance that conflicts with other information they have previously received and understood.