News release

Fatal 2012 mid-air collision over St. Brieux, Saskatchewan illustrates weakness of the see-and-avoid principle for VFR flight

Gatineau, Quebec, 15 August 2013 – The Transportation Safety Board of Canada (TSB) today released its investigation report (A12C0053) into the fatal May 2012 mid-air collision between a PiperPA-28R-200 Arrow and a Lake LA-4-200 Buccaneer near St. Brieux, SK.

On 12 May 2012, the Piper Arrow was descending eastbound in preparation for landing at the St. Brieux airport with 1 pilot and 2 passengers aboard. Meanwhile, the Lake Buccaneer with 1 pilot and 1 passenger aboard was flying northbound at 4500 feet toward La Ronge, SK. The 2 aircraft collided approximately 8 nautical miles west of St. Brieux at approximately 4500 feet. There were no survivors and both aircraft were destroyed. 

Both aircraft were flying under visual flight rules (VFR). In uncontrolled airspace, VFR aircraft rely on the see-and-avoid principle, where pilots must look out for other aircraft and take evasive action if necessary. The converging position of the 2 aircraft relative to each other would have made it very difficult for each pilot to see the oncoming aircraft. The reaction time available was reduced to a point where collision avoidance was not possible.

As mentioned in a previous TSB aviation occurrence report (A06O0206), aircraft operating in VFR are at continued risk of collision when the see-and-avoid principle is relied upon as the sole means of collision avoidance. While both aircraft were seen on air traffic control (ATC) radar, neither was required to communicate with ATC in the vicinity of the accident site. Both aircraft were also equipped with passive collision avoidance systems. The investigation could not determine if they were operational at the time of the accident, but there is a risk that these systems can be set to detection parameters resulting in insufficient warning time to pilots.


The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-994-8053
Email: media@tsb.gc.ca