Formal declaration of the Malaysia Airlines MH370 disappearance as an accident frees the carrier to begin certain procedural work, but the causal factors behind the loss remain undetermined.

The investigation has reached no conclusions over the reasons behind the Boeing 777-200ER’s vanishing while en route to Beijing on 8 March last year.

No trace of the aircraft has been located but the Malaysian government referred to the definition of ‘accident’ afforded by Annex 13 to the Chicago Convention – a definition based purely on the status of the aircraft and its occupants, not the circumstances.

Annex 13 defines an accident as an occurrence associated with aircraft operation which results either in substantial airframe damage – with the exception of certain components – or fatalities or serious injury among those on board.

It also applies to situations in which an aircraft is listed as missing, the status adopted when official search efforts have been terminated without the location of wreckage.

Given the time elapsed since satellite communications data tracked the aircraft to a remote part of the southern Indian Ocean, with no landing area, the Malaysian government considers improbable that any of the 239 occupants survived.

The unlikelihood of finding survivors had already been conveyed in April last year, when the Australian government stated that the surface search effort would transition to an underwater phase.

While the search for the wreckage is continuing, the Malaysian government says that, under the circumstances, survivability after 327 days would be “highly unlikely” – a declaration sufficient to meet the Annex 13 definition of ‘accident’.

But this does not rule out any of the scenarios which might have led to the loss. The Annex 13 definition does not limit the term ‘accident’ to any specific causal factor, stating only that the occurrence must have taken place between boarding and disembarkation of passengers or crew.

This distinction notably meant that the fire on an empty parked Ethiopian Airlines Boeing 787 at London Heathrow in July 2013 fell outside of the definition of an accident or serious incident, and UK investigators had to specially categorise the event in order to invoke the normal protocols.

Investigators have yet to determine whether – outside of the Annex 13 definition – the loss of MH370 was accidental, in the conventional sense of the term, or the result of possible deliberate intervention.

Authorities are still pursuing both a safety inquiry and a criminal probe into the aircraft’s disappearance. But the government says that both investigations are being “limited” by the lack of physical evidence, and the inability to locate the crash site and the flight recorders, and none of the possible causes behind MH370’s loss can be substantiated.

Malaysia’s government believes, however, that the formal ‘accident’ declaration – while not resolving the crucial questions over the cause of the loss – will assist with compensation efforts. The airline says it will “proceed with the compensation process” following the decision.

Source: Cirium Dashboard