What happened
On a scheduled flight from Toronto Lester B. Pearson International Airport to Vancouver, WestJet Flight 699, a Boeing 737-700, experienced a runway incursion during its takeoff roll. While the aircraft was approximately one-third of the way down Runway 33L, three aircraft rescue and firefighting (ARFF) vehicles entered the same runway. The aircraft had been cleared for takeoff at 11:42:27, and the vehicles entered the runway shortly thereafter. Although the tower controller attempted to instruct the crew to abort the takeoff, the aircraft was already at rotation speed and continued the roll, eventually lifting off approximately 25 and 500 feet from the vehicles.
The investigation
The investigation examined the coordination between the north tower and north ground controllers during a transition in runway operations. At the time, the airport was switching its preferential runway policy due to the serviceability of the Instrument Landing System (ILS) on Runway 05. While the north tower controller had taken ownership of Runway 05, the ownership of Runway 33L had not been formally transferred back to the north ground controller.
Investigators looked into the movement of the ARFF vehicles, noting they were traveling to a fire training area and did not have an operational necessity to cross the active maneuvering area. The investigation also reviewed the functionality of the airport surface detection equipment (ASDE) and its runway incursion monitoring system, which issued both amber and red alerts as the conflict developed.