Airlines are subject to a unique blend of national and international laws. Among the most interesting questions arising from this milieu is what the word "accident" means. This is important since, if a person is injured on board an aircraft and no "accident" has occurred causing the injury, the airline cannot be held liable.
Canada signed the 1999 Montreal Convention (designed to update the 1929 Warsaw Convention, to which Canada also belongs) which provides at Article 17 that:
The carrier is liable for damage sustained in case of death or bodily injury of a passenger upon condition only that the accident which caused the death or injury took place on board the aircraft or in the course of any of the operations of embarking or disembarking.
This wording resembles that in the Warsaw Convention, allowing older cases under the Warsaw Convention to inform interpretation of the Montreal Convention.
The 1985 United States Supreme Court judgement in Air France v. Valerie Hermien Saks is the leading decision on the meaning of "accident." In Saks, the Court determined that it must be the accident that occurs that causes the injury for an airline to be liable. To clarify, injury must be "… caused by an unexpected or unusual event or happening that is external to the passenger." The Court explains this definition is to be flexibly applied, considering all of the surrounding circumstances.
Given the judgement in Saks, it seems and accident is something "unusual" or "unexpected."
Canadian Courts followed the American lead. In two cases related to turbulence, the 1994 decision in Rena Ann Quinn v. Canadian Airlines International Ltd. and in 2001, Koor v. Air Canada, the Courts determined that the plaintiffs who suffered injury during turbulence were not entitled to compensation since the turbulence was not severe enough to be called "unusual."
What About Omissions?
Until recently, unlike in tort law, omissions did not seem to be enough to cause liability. In the 2002 Ontario case McDonald v. Korean Air, the plaintiff, McDonald, contracted deep vein thrombosis and was hospitalized for 11 days. McDonald claimed the airline was negligent, as it did not inform him of the risk of DVT associated with long flights, and that this failure to warn was an "accident" under Article 17. The Court held that:
… in not advising passengers of the risk they assume, an airline may be negligent, but this negligence is not in itself an accident within the meaning of Article 17 in the sense that the DVT sustained by the passenger is not linked to an unusual and unexpected event external to him as a passenger.
This decision was upheld at the Court of Appeal, and leave to appeal to the Supreme Court of Canada was denied.
What "Accident" Means in Canada
Given the weight of case law above, "accident" in Canada seems to mean an "unusual or unexpected event or happening" taking into account the specific circumstances.
Until recently, case law indicated that an accident could not be merely an omission to do something. A positive event or action had to occur. Airlines must be conscious, however, of a trend in the jurisprudence making airlines liable for omissions.
McCarthy Tétrault Notes
While airlines have until recently been sheltered from liability stemming from omissions, this is changing. In the 2004 American decision in Husain v. Olympic Airways the passenger was allergic to cigarette smoke. The flight attendant refused to move the passenger away from the smoking section. The passenger died, and Olympic Airways was held liable. The United States Supreme Court determined:
The distinction between action and inaction (…) would perhaps be relevant were this a tort law negligence case. But (the airline) vigorously rejects that a negligence regime applies under Article 17 of the Convention. The relevant "accident" inquiry under Saks is whether there is an "unexpected or unusual event or happening."
While ultimately determining that it did not have jurisdiction to decide the matter, the Ontario Superior Court followed Husain in the 2010 case Balani v. Lufthansa German Airlines Corp. The Court decided Lufthansa’s refusal to provide a wheelchair was sufficient to found liability, after a passenger fell and sustained injuries.
In short, recent case law puts airlines on notice that there is a movement in Canadian interpretation of the Montreal Convention to assign more liability to airlines. The effect is to impose a positive, tort-like duty upon airlines.