What happened
Between June 2012 and November 2017, a series of 27 runway incursions occurred at the south complex of Toronto/Lester B. Pearson International Airport (CYYZ). In these incidents, aircraft landed on the outer runway, Runway 06R/24L, and were instructed by air traffic control to hold short of the inner runway, Runway 06L/24R. Despite instructions to stop, several aircraft crossed the holding positions and entered the inner runway surface.
While air traffic controllers often identified these incursions quickly and intervened to prevent collisions, some aircraft did reach the runway surface. In one notable instance, a departing aircraft continued its takeoff roll because the crew did not recognize an abort instruction due to unfamiliar phraseology.
The investigation
The TSB examined the taxiway configuration between the two closely spaced parallel runways. The investigation established that the runways are separated by only 3ally 305 metres. The rapid exit taxiways (RETs) at this location are unique because they allow aircraft to transition directly to the adjacent runway without an intermediate surface. Additionally, the holding positions are located after a sharp 65-degree curve and are positioned further from the protected runway area than is standard at most other airports.
The study found that US-based regional airlines operating regional jets were involved in a disproportionate number of these incursions. The investigation suggested that foreign crews, unfamiliar with this specific layout, were often traveling at higher speeds and failed to anticipate the location of the stopping points.
Findings
- The primary cause of the incursions was the failure of flight crews to recognize visual holding position cues due to the unusual taxiway geometry and high taxiing speeds.
- Post-landing checklists and routines often distracted crews at the exact moment they needed to monitor the taxiway for holding positions.
- While the area was marked as a "hot spot" on airport charts, existing taxi briefings and procedures did not provide sufficient mitigation strategies.
- The direct access provided by the RETs from one runway to the next created a high-risk environment for aircraft exiting the outer runway.