Runway Environment and Visual Cues
On Runway 06, extra pavement existed on both sides where aircraft lined up for takeoff. No markings or lighting delineated this area, offering no visual cues that the pavement was adjacent to the runway. Consequently, the area likely appeared as an extension of the usable runway. This matched the observation in the second incident, where a pilot reported seeing 'plenty' of runway to the right when aligned on the right runway edge.
Although the runway had all required markings per regulations, two pilots reported them as difficult to see at night and 'scuffed', reducing contrast and visibility. Reflective paint, which could improve night conspicuity, was not used.
Taxiway and Runway Lighting
Taxiway centerline markings existed but no lead-on lights from the taxiway to the runway centerline. Lead-off lights were unidirectional, visible only when exiting the runway. Thus, at night pilots had limited cues when transitioning from taxiway to runway to ensure centerline alignment.
Runway 06 lacked centerline lighting. The first two edge lights on each side were white and inset, sharing characteristics of centerline lighting. Pilots, who indicated they more frequently used Runway 03/21 (fitted with centerline lights), may have misidentified edge lights as centerline lights.
Pilot Observations and Confirmation Bias
Two pilots operating a Cessna 441 commented that despite aircraft lighting being on, the environment appeared dark. One pilot reported limited ambient lighting at the intersection of Taxiway V with Runway 06. Reduced visual cues and runway features that could be misidentified may have given the impression that the aircraft were aligned with the centerline, increasing misalignment risk. These characteristics were evident in many previous similar investigations.
Consistent with ATSB research, the extra pavement, absent lead-on and centerline lights, and degraded markings were factors influencing misaligned takeoffs at night. A combination of these factors in each incident supported pilots' belief that aircraft were correctly aligned when positioned on runway edge lighting. Confirmation bias—the tendency to seek information confirming a held hypothesis—led pilots to commence takeoff roll believing they were aligned.
Flight Crew Attention
In the first incident, the flight crew divided attention between pre-takeoff tasks in the cockpit and monitoring the environment. They also received takeoff clearance while turning onto the runway, requiring communication with air traffic control. While normal, these tasks can divert attention from the external environment at a critical time, such as while lining up.
Pilot Responses
Pilot responses to each misaligned takeoff differed. In the June 2023 incident, the crew identified they had lined up on the runway edge lighting during the takeoff roll, maneuvered toward the centerline, and continued. Believing they had not struck runway lights, the misalignment was not reported until arrival in Sydney about four hours later. Subsequent inspections found no damage, but unrecognized debris could have affected other aircraft or the flight continuing with unknown damage.
In the August 2023 incident, the pilot detected an impact during takeoff but initially did not notice alignment with edge lighting. Having detected a problem, the pilot returned to the airport to ensure no aircraft damage and to allow a runway inspection. The pilot's decision was important as damage to the aircraft (which [source cuts off])
Investigation Findings
The investigation noted that a combination of reduced visual cues and runway features that can be misidentified likely contributed to the misalignments. No probable cause was explicitly stated.