Air accident investigation and liability

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Air accident investigation and liability

The laws and conventions governing air accident investigation and air carrier liability are complex, involving issues of domestic and international law. This article aims to provide a brief overview of the process that a typical investigation of an accident[1] or serious incident[2] will follow, along with some of the key sources of legislation which are relevant from a UK perspective.


Accident Investigation and Reporting

In the United Kingdom the Air Accidents Investigation Branch (also known as the ’AAIB’) is tasked with investigating accidents and serious incidents involving civil aircraft within the UK, its overseas territories and crown dependencies. The AAIB, which is an independent unit within the government’s Department for Transport, also investigates accidents or serious incidents involving civil aircraft registered in the UK, the Channel Islands, the Isle of Man and other British Overseas Territories, regardless of the location of the occurrence.


In carrying out its investigations the AAIB aims to identify and explain the circumstances and causes of accidents and serious incidents, publishing its findings in publicly available reports. Importantly, the AAIB does not seek to apportion blame or liability on those involved.


The European Aviation Safety Agency (‘EASA’) and the UK Civil Aviation Authority (‘CAA’) are obliged to provide the AAIB with information that it requires in support of its investigation; for example, certification data, occurrence reporting information or personal licensing information.


Depending on the complexity of the accident or serious incident the AAIB’s investigation and report can take several years to conclude, and its findings can often turn out to be quite different from initial media speculation. This means that the investigation of the accident or serious incident will often continue alongside legal proceedings arising out of the occurrence, which much be commenced within strict time limits (addressed in further detail below). During the course of the investigation the AAIB will often need to interview a number of people, cross-check and verify evidence, examine potentially suspect equipment, and consult with an array of technical experts. European legislation nevertheless stipulates that a preliminary report should be issued after 12 months following the accident or serious incident detailing the progress made and any safety issues identified, followed by publication of a final report as soon as possible thereafter.


Prior to its publication a draft copy of the report is sent to the individuals involved or their representatives, and also to those persons or organisations whose reputations may be adversely affected by the AAIB’s findings. They then have a period of 28 days in which they can make representations before the report is finalised and published.


Where appropriate, the AAIB’s report will contain safety recommendations aimed at reducing the likelihood of a recurrence of the relevant circumstances in the future.


Where fatalities have been suffered in unusual circumstances, Her Majesty’s Coroner or Procurator Fiscal (if the accident occurred in Scotland) will normally open an inquest or fatal accident inquiry shortly after it has happened. These proceedings are typically adjourned until the AAIB has concluded its investigation.  AAIB Inspectors prepare statements for the courts and are often required to appear as expert witnesses.


The need for representation at and participation in these proceedings can potentially extend to all parties involved in the accident or incident; not just the air carrier and crew; for example, manufacturers, air traffic control, and airport authorities.


The legal framework


The legal framework which covers aircraft accidents and serious incidents is complex and multi-layered. Accident investigation in the UK is governed primarily by the Civil Aviation (Investigation of Air Accidents and Incidents) Regulations 1996 and by Regulation EC 996/2010 on the investigation and prevention of accidents and incidents in civil aviation.


Legislation at both EU and UK domestic level has evolved against the backdrop of the Convention on International Aviation (more commonly know as the ‘Chicago Convention’), which was signed on 7 December 1944. The Chicago Convention gave birth to the development of civil aviation after the Second World War as we now know it, and set out to establish a set of uniform worldwide rules regulating the activities of the international aviation industry as a whole, not least ‘Annex 13’ to the Chicago Convention, which established international standards (essential requirements) and recommended practices (desirable, rather than essential) for aircraft accident and incident investigation. The success of the Chicago Convention in bringing about the implementation of the standards and recommended practices has to an extent been hampered by their implementation being qualified and subject to the proviso that their adoption by individual states can be restricted to the extent permitted by their national laws. This has compromised the uniformity of standards and recommended practices, and individual states continue to be required to publish any differences which exist between their national laws and the provisions of the Chicago Convention.    


The Chicago Convention is not the only international convention which plays a key role in working towards uniformity and predictability. Certain other conventions also play key roles, particularly in addressing the question of liability in circumstances where accidents or incidents have occurred.


The Montreal Convention, a well known multilateral treaty first adopted in 1999 (formerly known as the Unification of Certain Rules for International Carriage by Air) is of particular importance, laying down global rules on the liability of air carriers in the event of accidents and incidents involving flights between contracting states. At the time of writing 116 of ICAO’s 191 member states have adopted the Montreal Convention, and this number is gradually increasing.


The Montreal Convention, incorporated into English domestic law through the Carriage by Air Act 1961, seeks to enhance uniformity and predictability on the question of air carrier liability in respect of passengers, their baggage, and cargo in the event of accidents or serious incidents. It provides a strict liability regime for air carriers in respect of death or injury to passengers, and loss or damage to baggage and cargo, without those affected having to prove fault on the part of the air carrier:


  • For death or injury to passengers, liability is strict up to a limit of 113,100 Special Drawing Rights[3] (SDRs) per passenger, and passengers do not need to prove negligence on the part of the carrier.
  • For claims in excess of 113,100 SDRs carrier liability is not limited but can be defended if the carrier can demonstrate that the event which caused the death or injury was not caused by their negligence, or was caused by the negligence of a third party.
  • Liability for loss, destruction damage, or delay to baggage is limited to 1,131 SDRs per passenger, unless a higher value has been declared.
  • Liability for loss, destruction, damage or delay to cargo is limited to 19 SDRs per kilogram, subject to any higher value declared by the shipper.

The liability provisions of the Montreal Convention applies to EU carriers by virtue of article 3(1) of Regulation EC 889/2002, which also includes a requirement that EU carriers hold liability insurance to a level which is adequate to cover payment of the full amount of compensation to which all affected persons are entitled.    


For many countries the Montreal Convention superseded and replaced the Convention for the Unification of Certain Rules relating to International Carriage by Air, commonly known as the Warsaw Convention, which was first signed in Warsaw on 12 October 1929. The Warsaw Convention (as supplemented and amended by the Hague Protocol of 1955, the Guadalajara Convention of 1961 and a number of further protocols) remains applicable for a number of states which have not adopted the Montreal Convention. Whilst the Warsaw Convention does address the question of liability, assuming liability on the part of carriers in respect of death or injury suffered by passengers, and damage or loss of baggage and cargo (subject to some limited defences), it also - in contrast with the Montreal Convention - limits carrier liability to 16,600 SDRs for death or injury to passengers, and 17 SDRs in respect of checked baggage or cargo, subject to any higher limits agreed between the carrier and passenger. The continuing application of the Warsaw Convention for some countries, coupled with the fact that a number of other countries are yet to adopt either the Warsaw or Montreal Conventions, mean that there is still significant uncertainty on the question of air carrier liability in some parts of the international aviation market place.    


A somewhat restrictive feature of both the Montreal and Warsaw Conventions is a strict requirement for damages claims to be brought by those affected (or their representatives) no later than two years either from the date of arrival of the aircraft at its destination, or from the date on which the aircraft ought to have arrived at its destination, or from the date on which the carriage stopped. This means commencing court proceedings within this period, failing which the right to claim damages is extinguished. That a right of action is ‘extinguished’, rather than ‘time-barred’, if an action is not brought within two years can be significant. Unlike in the case of the latter, where a right of action is extinguished the time limit cannot be extended by agreement of the parties involved, or with the permission of a Court. The extinguishment of a right of action is absolute and permanent.    




The investigation of air accidents by the AAIB and its overseas counterparts is crucial to the ongoing improvement of aviation safety. Unsurprisingly, given the international nature of the aviation industry, the legal framework applicable to those accident investigations and associated questions of legal liability is complex, involving (in the case of the UK, for example) interaction between international conventions, EU law and domestic law. These laws seek to balance the interests of air carriers with those of passengers and charterers, as well as seeking uniformity and predictability in how different nations investigate accidents and determine questions of liability. The gradually increasing number of countries adopting the Montreal Convention will assist in these aims. However, there is still much work to be done, particularly in what are likely to be key emerging markets in aviation.

[1] A detailed definition of ‘accident’ can be found in article 2(1) of EC Regulation 996/2010 on the investigation and prevention of accidents and incidents in civil aviation. Broadly speaking, ‘accident’ refers to an occurrence in which a person is fatally or seriously injured as a result of being in or in contact with any part of an aircraft, or in which an aircraft sustains significant damage, or in which an aircraft goes missing.

[2] ‘Serious incident’ is defined in article 2(16) of Regulation 996/2010. Broadly, it refers to an occurrence associated with the operation of an aircraft in which there was a high probability of an accident occurring; for example, flight crew incapacitation, system failures, and near misses requiring avoidance action by crew.  

[3] The value of Special Drawing Rights is based on a mix of key international currency values, which is reviewed by the International Monetary Fund every 5 years. Currency units per SDR can be found online here.


This article was published in Airline Economics Law Yearbook 2016 – read the online edition here.


Author: Simon Amos, Solicitor

Alina Nosek, Partner, AviationFor more information on aviation law or related enquiries, contact Alina Nosek, Head of Aviation.

View Alina's profile email Alina now

Published: 2 Mar 2016

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