In the Wikipedia article Canada–United States border, there are several airports mentioned where the airport straddles the US-Canada border, in some cases the runway even being partially in the United States and partially in Canada.

If there was an accident at one of those airports, what agency would investigate the accident (i.e. the NTSB or the Canadian equivalent (the TSB?))

I'm specifically thinking of an accident that might have begun on one side (such as hitting the runway too hard on touchdown, or a botched approach), and led to something happening on the other side (such as an overrun, or a loss of control on the runway).

  • $\begingroup$ Probably both in a joint investigation, or even more if it is a foreign airline (for example an European airline the CAA would also investigate). Even more if there are other foreign nationals the countries of their citizenship may also request to investigate. Additionally if foul play is involved it could get the FBI or Interpol in the mix. $\endgroup$
    – Ron Beyer
    Commented Feb 10, 2018 at 4:26
  • $\begingroup$ @RonBeyer I'm sure it would be a joint investigation, however even still I'd imagine there has to be one agency in charge. $\endgroup$ Commented Feb 10, 2018 at 4:29
  • 3
    $\begingroup$ And where do you bury the survivors? $\endgroup$ Commented Feb 10, 2018 at 4:43
  • 2
    $\begingroup$ @RonBeyer I apologize, I was alluding to an old trick question. The punch line is that you don't bury survivors. $\endgroup$ Commented Feb 10, 2018 at 4:56
  • 1
    $\begingroup$ @WayneConrad You do eventually. Typically, at least. However, in such a case it's normally unrelated to aviation. $\endgroup$
    – user
    Commented Feb 10, 2018 at 22:32

2 Answers 2


By ICAO conventions, the lead investigator is the country in which the accident/incident occurs, unless otherwise delegated. This is fairly common: for example an engine fails in Canadian airspace but they divert to Iceland, it's initially Canada's responsibility.

So you have an argument for whatever country the airplane hit the ground first in your example of a hard landing.

Additionally, ICAO Annex 13 recommends that if the country can't be decided, the state of registry should conduct the investigation:

5.3 When the location of the accident or the serious incident cannot definitely be established as being in the territory of any State, the State of Registry shall institute and conduct any necessary investigation of the accident or serious incident. However, it may delegate the whole or any part of the investigation to another State by mutual arrangement and consent.

Practically, I would imagine they would delegate the investigation to the country of registry of the aircraft, since that's where the tax dollars were paid.


It would be a joint crash investigation as intuition and history would suggest.

The formal basis for this is generally covered by the Chicago Convention on International Civil Aviation which established the ICAO, The International Civil Aviation Organization in 1944, a specialized agency of the UN charged with coordinating and regulating international air travel.

Cross border incidents are not unknown and the ICAO recognizes LOA (Letters of Agreement) between States that have airports or significant air traffic near common borders. For instance there are bi-lateral agreements between the Netherlands and Germany and Switzerland and Germany as to how Air navigation services and accident investigations are handled.

Similar to LOA, Canada and the United States concluded a bi-lateral agreement in 1963 under the somewhat ponderous title of Exchange of Notes Constituting an Agreement Between The United States of America and Canada Relating To Air Traffic Control.

Essentially recognizing the respective sovereignty of each State's airspace, co-operative operation of air-navigation services and related operational issues.

Lower level government agencies were specifically authorized to set policies for issues not already federally regulated where common interests and agreement were found, with the result that there is a legally sanctioned bilateral agreement to let the accident investigation boards of both countries determine most of the policy for and co-operate in investigating aircraft crashes occurring within 50 miles of the common international border.

The Chicago Convention on International Civil Aviation

Treaties and international agreements registered or filed and recorded with the Secretariat of the United Nations

Agreement between the Government of Canada and the Government of the United States of America for Promotion of Aviation Safety

Cross-border provision of Air Navigation Services with specific reference to Europe By Niels Van Antwerpen

(Preceding thesis by the same title)


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