More than a year after a plane nearly collided with a maintenance van at Pearson International Airport, an investigation into the incident reveals that warnings calls to the flight crew were not heard.

In a report released on Wednesday, the Transportation Safety Board of Canada (TSB) said two calls to the Air Canada plane went unnoticed as it approached the Sunwing Airlines vehicle. The plane then flew approximately 10 metres above the van, before safely landing.

"The first air traffic control instruction to the Embraer's flight crew to go around (the van) was masked by the sound of the ground proximity warning system in the cockpit," a statement from the TSB said. "The second go-around instruction went unnoticed by the flight crew because it was truncated and the crew did not hear the aircraft call sign."

Last March, an Air Canada flight that was preparing to land almost struck a maintenance van that was inadvertently rolling. The incident happened at approximately 11:40 p.m.

Wednesday's report also found that the van's gear was in drive mode. It had rolled across the arrival runway and was left unattended while the technician was performing his duties. No one was injured as a result of the incident.

Following the near collision, the Greater Toronto Airports Authority reminded workers that leaving vehicles idling and unsecured was prohibited.