Accident

(1) An accident is an occurrence associated with the operation of an aircraft that takes place after the time any person boards the aircraft with the intention of flight and no later than the time all persons who boarded with that intention have disembarked, if applicable, in which —

(a) a person is fatally or seriously injured as described in paragraph (2);
(b) the aircraft sustains structural failure or damage as described in paragraph (3); or
(c) the aircraft is missing or is completely inaccessible.

(2) For paragraph (1)(a) —

(a) the death or injury must result from the person's —

1. being in the aircraft;
2. direct contact with any part of the aircraft, including parts that have become detached from the aircraft; or
3. direct exposure to jet blast;

(b) the death or injury must not be from a natural cause, self-inflicted or inflicted by another person; and

(c) the person must not be a stowaway hiding outside the areas normally available to the passengers and crew.

(3) For paragraph (1)(b), the failure or damage must —

(a) adversely affect the structural strength, performance or flight characteristics of the aircraft;

(b) be such as would normally require major repair or replacement of the affected component; and

(c) be none of the following-

1. engine failure or damage that is limited to a single engine (including its cowlings or accessories);
2. damage that is limited to propellers, wing tips, antennas, probes, vanes, tires, brakes, wheels, fairings, panels, landing gear doors, windscreens or the aircraft skin (such as small dents or puncture holes);
3. minor damage to main rotor blades, tail rotor blades, landing gear, or resulting from hail or bird strike (including holes in the radome).".

Source: with reference to Annex 13 to the CONVENTION ON INTERNATIONAL CIVIL AVIATION - AIRCRAFT ACCIDENT AND INCIDENT INVESTIGATION. The document can be purchased from the website of International Civil Aviation Organization.