Incident Details
On an unspecified date at Calgary International Airport, Alberta, a Cessna 172 (C-GVLO) operated by Calgary Flight Training Centre was cleared to backtrack runway 25 and told it was number one for takeoff. An Airbus A319 (Air Canada Flight 185, ACA185) holding on runway 16 was subsequently cleared for takeoff. Both aircraft commenced takeoff, but C-GVLO did so without takeoff clearance. When the pilot of C-GVLO called "rolling", the controller immediately instructed him to abort, but the pilot continued. The controller then instructed ACA185 to abort its takeoff, which it did at approximately 120 knots, stopping with about half the runway length remaining. Emergency Response Services were requested for ACA185 as a precaution due to possible hot brakes.
Aircraft and Pilot Information
The Cessna 172 pilot held a private license, had approximately 75-80 hours of flight experience, and was building time for a commercial license. The flight was planned as an informal upper air work review using a rental aircraft. The pilot had flown four to five hours in the previous ten days. The Airbus A319 was operating as Air Canada Flight 185; the source does not specify flight crew details.
Air Traffic Control
The Calgary Tower controller had ten years of experience, five at Calgary. Due to Saturday staffing, the tower coordinator position was not staffed, requiring the controller to perform additional tasks, including manipulating the electronic data strip and administrative duties. After issuing takeoff clearance to ACA185, the controller diverted attention to locate a computer mouse to record departure times. He did not observe simultaneous movement until the Cessna pilot called rolling. The NAV CANADA ATC Manual of Operations specifies that when sequencing multiple aircraft for takeoff on intersecting runways, the second aircraft should be advised of the preceding departure. In this incident, the controller did not inform C-GVLO of ACA185's departure sequence.
Aftermath
The pilot of C-GVLO reported not being aware of ACA185 on runway 16 and not hearing its takeoff clearance, despite being on the same frequency. He believed he had authorization to take off. He momentarily applied brakes but continued after seeing ACA185. The controller's instruction to abort was not heard by the Cessna pilot. The A319 came to a stop safely, and emergency services were called as a precaution.