What happened
On 15 July 2024, a QantasLink De Havilland Aircraft of Canada Limited DHC-8-402, registered VH-QOD, entered runway 05 at Wagga Wagga Airport. At the same time, a Piper PA-28, registered VH-XDK, was beginning its take-off roll from the opposite end of the runway, runway 23. The crew of the Dash 8 was unaware of the departing aircraft until the crew of a Saab 3D40 notified them of the potential conflict. Upon realizing the danger, the Dash 8 captain halted the aircraft and used reverse thrust to back away from the runway. Simultaneously, the pilot of the PA-28 aborted their take-off.
The investigation
The investigation focused on why the two aircraft failed to identify each other. While the PA-28 crew performed the required positional radio broadcasts, they operated under the assumption that the Dash 8 crew had heard them. However, the Dash 8 crew did not hear the PA-28's transmissions and did not visually spot the aircraft, partly because their line of sight was momentarily blocked by a landing Saab 340. Additionally, the PA-28's transponder was not active during the taxi phase, meaning it was not visible to the Dash 8 crew via electronic means.
Findings
- The De Havilland Aircraft of Canada Limited DHC-8-402 entered the active runway while the Piper PA-28 was already accelerating for departure.
- The PA-28 crew relied on one-way positional broadcasts and did not attempt direct radio contact with the Dash 8 crew to confirm separation.
- The PA-28 was not broadcasting transponder information during its taxi, as the operator's manual only required activation prior to entering the runway.
- Reduced VHF radio clarity was noted at the eastern end of runway 23, which likely prevented the Dash 8 crew from receiving the PA-28's calls.
- The Dash 8 crew's use of a specific radio frequency (COM 2) further contributed to the difficulty in receiving clear communications from other aircraft.
Safety message
- Activating transponders during taxi can provide vital electronic positional data to aid 'see-and-avoid' efforts.
- Pilots should attempt direct radio contact with other aircraft to confirm awareness and arrange separation, rather than assuming broadcasts have been received.