An aviation accident is defined in the Convention on International Civil Aviation Annex 13 as an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, in which a person is fatally or seriously injured, the aircraft sustains damage or structural failure or the aircraft is missing or is completely inaccessible.
An aviation incident is also defined there as an occurrence other than an accident, associated with the operation of an aircraft, which affects or could affect the safety of operations.
An accident in which the damage to the aircraft is such that it must be written off, or in which the plane is destroyed is called a hull loss accident. 
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