What happened
During the early hours of 15 October 2022, a runway incursion occurred at Toronto/Lester B. Pearson International Airport. A maintenance vehicle, identified as Maintenance 31 and operated by the Greater Toronto Airports Authority, entered the east side of Runway 15R via Taxiway J. This movement occurred after the vehicle had crossed the runway holding position marking.
At the moment of the incursion, an Air Canada Boeing 737 (flight ACA 174) was on its final approach to Runway 15R, positioned roughly 0.5 nautical miles from the runway threshold. The tower controller, observing the approaching aircraft from the tower cab, noticed the vehicle on the runway and immediately instructed the flight crew to execute a go-around. The crew followed the instruction, rejoined the approach, and successfully landed the aircraft at 0025 Eastern Daylight Time.
The investigation
The investigation focused on the actions of the maintenance vehicle and the adherence to taxi clearances. It was established that the driver of the vehicle had received and read back a specific taxi clearance that included an instruction to hold short of the runway, yet the vehicle proceeded past the holding position marking.