On Wednesday, the Transportation Safety Board of Canada (TSB) released its investigation report into a runway incursion and risk of collision that occurred at Toronto Pearson International Airport last year. 

Shortly after midnight on Oct. 15, 2022, the driver of a maintenance vehicle, operated by the Greater Toronto Airports Authority (GTAA) crossed the displaced threshold of an active runway, even though the driver had received and read back an instruction to hold short. 

At the time of the runway incursion, an Air Canada Boeing 737, operating as flight AC174, was on final approach for the runway. 

The air traffic controller — who was watching the approaching aircraft through the window of the control tower — observed the incursion as it was happening and instructed the flight crew to go around for another approach. 

JUST RELEASED: #TSBAir investigation report (A22O0146) into the 2022 maintenance vehicle runway incursion & risk of collision with an @AirCanada Boeing 737 at @TorontoPearson.

More here: https://t.co/j6odNfCtKl pic.twitter.com/tU5ZlgmN2I

— TSB of Canada (@TSBCanada) December 20, 2023

According to the report, the flight crew complied and the aircraft landed uneventfully following a second approach. 

The investigation found that the driver's attention was split between his driving duties and the planning of the upcoming tasks that he would be supervising. 

"As a result, he was paying less attention to monitoring the route for hazards. As well, because the driver had crossed the runway at the displaced threshold many times without stopping, the mental model he developed did not include stopping at the holding position, even though he read back the instruction to hold short," the report reads. 

"Given the driver's split attention, the visual cues that were available to designate the holding position were not salient enough to alter his mental model and stop him from entering the runway." 

The transportation agency says that it has been monitoring runway incursions since 2010, and although the industry has made some improvements, "the overall rate of runway incursions continues to increase." 

According to the TSB, the runway incursion rate in Canada has risen from an average rate of 5.3 incursions per 100,000 arrivals and departures in 2010 to an average of 10.7 in 2021. 

Although there has not been a recent collision as a result of a runway incursion in Canada, the agency notes that the potential consequences of such a collision could be catastrophic. 

"Reducing the risk of runway incursions is a complex issue and requires collaboration from all sectors of the air transportation industry. There is no single solution that will reduce the risk of runway incursions nationwide," the agency wrote. 

"Safety is our top priority, and we take all incidents very seriously. Runway incursions are extremely rare at Toronto Pearson, and we work hard to make sure everyone stays safe on our airfield," GTAA spokesperson Sean Davidson told blogTO. 

"We are committed to learning from situations like this and will review the report in detail and continue to work with the Transportation Safety Board of Canada."