What happened
During recent operations, an experienced pilot was instructed to line up and wait on runway 2D. Although the pilot correctly read back the instruction to use runway 29R, the aircraft subsequently crossed runway 29R and entered runway 29C without authorization. The aircraft was moving onto a runway that was already occupied. The error was identified by both the pilot and the air traffic controller before the aircraft could begin its take-off roll, allowing the departure to be halted.
The investigation
Investigators examined the pilot's recent flight history and found that for the previous 18 months, they had consistently performed IFR departures using the centre runway. This pattern likely created a mental expectation that the departure would occur from runway 29C. While the pilot confirmed the instruction for runway 29R, they later reported having no memory of the specific clearance. It appears the pilot's focus had shifted toward the upcoming VFR departure procedures, causing them to revert to familiar patterns rather than focusing on the current taxi instruction.
On the air traffic control side, the controller observed VH-NSK entering runway 29R. However, the controller's attention was diverted by the management of two other helicopters operating near the airport. Because the pilot's readback appeared correct, the controller did not realize a misunderstanding had occurred and subsequently focused on other tasks, failing to notice the aircraft's continued movement onto the occupied runway.
Findings
- The pilot crossed runway 29R and entered runway 29C without clearance.
- Expectation bias stemming from a long-term pattern of using the centre runway for departures was a primary factor.
- The controller's attention was diverted by the presence of two helicopters in the vicinity, preventing the detection of the unauthorized runway entry.
- The pilot's cognitive focus was likely directed toward post-departure actions, reducing situational awareness regarding the taxi clearance.