What happened
On a clear night at Toronto / Lester B. Pearson International Airport, a Learjet 35A, registration N70AX, was taxiing toward Runway 05 for departure. The flight, operated by R & M Aviation Inc., was part of a mission to transport a patient. After receiving taxi instructions to hold short of Runway 05, the crew of N7 and AX proceeded along the taxiway.
While the pilot-in-command was navigating the airfield, the co-pilot was focused on performing the taxi-before-take-off checklist. During this process, the pilot-in-command misidentified a set of lights as the runway holding point and inadvertently crossed the hold line. At the same time, an IAI 1124 Westwind, registration C-FJOJ, was on its landing roll on Runway 05. The two aircraft came within approximately 60 feet of each other before the Westwind crew performed evasive maneuvers to pass behind the Learjet.
The investigation
The investigation examined the cockpit environment, the air traffic control (ATC) workload, and the airport's surface detection capabilities. It was established that the crew of N70AX was unfamiliar with the Toronto airport layout, having only visited during daylight hours previously. The investigation also reviewed the functionality of the airport's surface detection equipment (ASDE) and the runway incursion monitoring and conflict alerting system (RIMCAS).
Findings
- The crew of N70AX failed to hold short of the runway because they did not correctly perceive their position on the airfield.
- The co-pilot was not monitoring the taxi route or compliance with instructions because they were performing checklists while the aircraft was in motion.
- Operational pressures and fatigue, stemming from a long duty day, may have reduced the crew's alertness.
- The RIMCAS system provided an aural warning to controllers, but the warning occurred only nine seconds before the incursion, which was insufficient time for controllers to intervene and prevent the aircraft from entering the runway.
- The existing ASDE/RIMCAS software at the airport is aged and cannot be enhanced to provide the same level of protection found at other Canadian airports.