Transportation Safety Board is running the investigation, not Nav Canada.
Mandate
The TSB's mandate—as described in the Act that governs its work—is to advance safety in air, marine, pipeline, and rail transportation by
conducting independent investigations, including public enquiries when necessary, into selected transportation occurrences, in order to make findings regarding their causes and contributing factors;
identifying safety deficiencies, as evidenced by transportation occurrences;
making recommendations designed to eliminate or reduce such safety deficiencies;
reporting publicly on our investigations and findings in relation thereto.
While it is not the function of the Board to assign fault or determine civil or criminal liability, the Board reports fully on the causes and contributing factors of an occurrence, even in cases where fault or liability might be inferred from the Board's findings. Findings of the Board are not binding on the parties to any legal, disciplinary, or other proceedings.
To instill public confidence in the TSB, it is essential that the agency be free of any conflict of interest when investigating accidents, identifying safety deficiencies, and making recommendations. That is why the TSB is independent and separate from other government departments. It currently reports to Parliament through the President of the Queen's Privy Council for Canada.
The TSB's mandate is distinct from those of other organizations such as Transport Canada, the Canadian Energy Regulator, the Royal Canadian Mounted Police, the Canadian Coast Guard, and the Department of National Defense, all of which have a role in the transportation sector.
Transport Canada is concerned with developing and administering policies, regulations, and services for transportation systems in Canada with respect to federally regulated air, marine, and rail modes of transportation.
The Canadian Energy Regulator is responsible for regulating pipelines under federal jurisdiction.
As an independent federal agency, the TSB is not associated with any of these organizations. It does, however, cooperate with them when conducting investigations and making safety recommendations.
When the TSB investigates an accident, no federal department except the Department of National Defense and the Royal Canadian Mounted Police may investigate for the purpose of making findings as to the causes and contributing factors of the accident.
Transport Canada and the Canadian Energy Regulator may investigate for any other purpose, such as regulatory infractions.