Legal Instruments related to Aviation Security


Safety (i.e. the absence of danger for human life) and security (i.e. the protection from criminal acts) of international civil aviation have always been the goals of the International Civil Aviation Organization (ICAO). Although there were no major incidents by individuals in the early days of aviation, the vulnerability of civil aviation became apparent with the advent of the Cold War, the Cuban Revolution and the Palestinian problems. The Delegates at the Chicago Conference in 1944 could hardly have foreseen that, one day, hijackers and terrorists could turn the operational vulnerability and the fundamental openness of aviation into their dark opportunity.


So, from the late 1950s, aviation security took on a new meaning with the rise of an extremely violent terrorism against aviation and the unlawful seizure of aircraft, and became a key element of ICAO’s role in the world. On this issue, ICAO worked side-side with the International Air Transport Association (IATA). In addition to several national and regional bodies, other organizations made important contributions to the security: the International Federation of Airline Pilots’ Association (IFALPA) and the Airports Council International (ACI); moreover, some decisions taken by powerful national or regional aviation organizations (such as the Federal Aviation Administration – FAA, or the European Civil Aviation Conference - ECAC) are often followed by others around the word.


Concerns over terrorism and aviation security predated ICAO; the Comité International Technique d'Experts Juridiques Aériens (CITEJA) had already discussed these issues as early as 1926.


During its 9th Session from 25 August to 12 September 1953, the ICAO Legal Committee had officially established a subcommittee on The Legal Status of Aircraft to study the problems associated with crimes on aircraft. A first ICAO draft Convention on the Legal Status of the Aircraft was developed in 1958; the scope was expanded in 1959 to become a draft Convention on Offences and Other Acts Occurring on Board Aircraft. A final draft Convention on Offences and Certain Other Acts Committed on Board Aircraft was prepared in 1962 for consideration, finalization, and adoption by the Diplomatic Conference convened at Tokyo by the ICAO Council from 20 August to 14 September 1963. The Tokyo Convention (Convention on Offences and Certain Other Acts Committed on Board Aircraft) entered into force on 4 December 1969 bringing closure to ICAO’s efforts on the subject since the 1950s.


The Tokyo Convention was ICAO’s first step in what would become a major international effort to combat the spread of aviation terrorism. The 16th Session of the ICAO Assembly held in Buenos Aires from 3 to 26 September 1968 adopted Resolutions A16-36 on the Participation of States in International Conventions on Air Law and A16-37 on the Unlawful Seizure of Aircraft which called on the ICAO Council and the Member States to cope, at the earliest possible date, with the problem of unlawful seizure.


Further to that, the Council directed the Air Transport Committee and the Air Navigation Commission to initiate their own studies on the technical aspects related to the problems of airports and aircraft security; a new Committee on Unlawful Interference of Aircraft was created on 10 April 1969. The other major area for the Council’s action was, through the Legal Committee, which created a new Sub-Committee to either refine the Tokyo Convention or create a wholly new convention.


As the number of hijackings rose through 1969 and 1970 (118 incidents of unlawful seizure of civil aircraft and 14 incidents of sabotage and armed attacks against civil aviation occurred), an Extraordinary Assembly (17th) was held in Montreal from 16 to 30 June 1970, specifically on the subject of aviation security; it produced a series of resolutions dealing with a wide range of security measures, eventually leading to the adoption of a completely new Annex 17 - Security. The primary objective of each Contracting State is safeguarding its passengers, ground personnel, crew as well as the general public against any acts of unlawful interference.


During its 24th Session in December 1969, the United Nations General Assembly adopted Resolution 2551 (XXIV) in which the General Assembly stated its deep concern over acts of unlawful interference with international civil aviation. On 9 September 1970, the UN Security Council adopted Resolution 286 calling upon States to take all possible legal steps to prevent further hijackings or any other interference with international civil air travel. On 25 November 1970, the UN General Assembly adopted Resolution 2645 (XXV) which condemned without exception whatsoever all aerial hijacking or other interference with civil air travel caused through threat or use of force. The international community thus condemned terrorism against air transport by giving official recognition to such condemnation and called upon all States to contribute to the eradication of the offence by taking effective, preventive and deterrent measures. In the years after, the UN General Assembly adopted other resolutions calling for international cooperation dealing with acts of international terrorism.


In the atmosphere of crisis and on legal side, two new Conventions were prepared. From 1 to 16 December 1970, 77 States and 12 international organizations met in The Hague for a Diplomatic Conference ending with the signing of The Hague Convention for the Suppression of Unlawful Seizure of Aircraft (sometimes named the Anti-hijacking Convention), which came into force on 14 October 1971. This Convention provided for effective legal measures being taken to deter acts of unlawful seizure of aircraft through the cooperation of nations throughout the world. Action taken by ICAO and its Members States resulted in a considerable reduction of hijackings during 1971.


Prior to the Montréal Conference, the 18th Session of the ICAO Assembly, in Resolution A18-9 (held in Vienna, from 15 June to 7 July 1971), called for speedy adoption and ratification of what was to become the Montréal Convention. From 8 to 23 September 1971, a full Diplomatic Conference (attended by Delegates from 60 Member States and the United Nations, as well as by observers from one State and six international organizations) was held in Montréal and the Montréal Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation was opened for signature; it came into force on 26 January 1973. The Protocol for the Suppression of Unlawful Acts of Violence at Airports Serving International Civil Aviation, Supplementary to the Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation was signed at Montreal on 23 September 1971 (adopted on 24 February 1988).


With the rapid development of aviation transport industry, ICAO and its Member States concluded three traditional conventions that were widely recognized by the international community in the 1960s and 1970s: the Tokyo Convention, the Hague Convention and the Montreal Convention. 


In the years since 1968, the number of aircraft hijackings rose to very serious proportions. The total was further enlarged by politically-motivated acts of sabotage against aircraft and passengers, both in the air and on the ground. It is to remind that,

  1. On 24 November 1968, Pan Am Flight 281 (Boeing 707) was scheduled from JFK International Airport to San Juan, Puerto Rico; it was hijacked by 4 men from JFK airport to Havana, Cuba;
  2. On 6 September 1970, two men hijacked Pan Am flight 93, a Boeing 747–121 (which departed Brussels) route from Amsterdam to New York, as part of the Dawson's Field hijackings; the flight diverted to Beirut International Airport to take on board seven other gang members for the next leg to Cairo International Airport, where the hijackers ordered the aircraft evacuated and destroyed it with explosives. Note that the aircraft flew to Cairo instead of Dawson’s Field (a remote desert airstrip in Jordan, formerly a British Royal Air Force base), because the Jordan airfield was considered too small to accommodate a 747.


As a result of the numerous hijackings in those days, the International Federation of Air Line Pilots' Associations (IFALPA) was obliged to devote a major part of its efforts and resources to what had become its number one problem requiring a combined assault by governments through ICAO, by IATA and by IAFALPA.


The series of skyjacking incidents, several of them desperate and dramatic, was a great and particular concern for the Air Line Pilots Association (ALPA, Member of IFALPA, the largest airline pilot union in the world representing pilots from U.S. and Canadian airlines); ALPA sought an innovative step and an extraordinarily direct method to intensively lobby influential politicians from all over the world, as the fundamental problem in advancing a solution to the skyjacking problem laid in the realm of politics. A Boeing 747 sponsored by ALPA was rented from Pan Am and nearly 300 United Nations personnel flew on Saturday 6 November 1971 on a short international flight from New York to Montréal, being the home of ICAO; the aircraft was piloted by Captain Stanley L. Doepke of Pan Am. More than 30 crewmembers who had been skyjacked placed these world political leaders in a controlled and dramatic situation where they could hear their stories. All the international politicians from the UN General Assembly who accepted ALPA’s hospitality on the Montréal excursion went home vowing immediate action by their countries. A special first day cover was issued to commemorate this unique event and a medal was given to the UN Delegates. More information on this issue can be obtained by clicking on the following link: Hijacked Pilots Urge UN Action.


However, even with these two new Conventions signed in 1971, the issue on sanctions was not sufficiently addressed and a few terrorist actions early in 1972 gave rise to grave concern and threat to the safety of civil aviation; it was felt that perpetrators of such acts were not or not appropriately brought to justice. Because governments had failed to deal adequately with such hijacking, the International Federation of Airline Pilots' Associations (IFALPA) called for a world-wide 24-hour shutdown of services by pilots on 19 June 1972. The United States pressed in the ICAO Council for rapid action to complete the work on a convention which would provide for sanctions against states that did not punish hijackers. The ICAO Council adopted on 19 June 1972 a Resolution which directed the Legal Committee to convene immediately a special Subcommittee to work on the preparation of an international convention to look at this issue of sanctions.


The American Government invited this Subcommittee to meet in Washington from 4 to 15 September 1972 and held 21 meetings; however, no agreement was reached at this meeting and more work was done over the following year. To consider various proposals for multilateral agreements relating to the suppression of acts of unlawful seizure of aircraft and relating also to other unlawful interference with international civil aviation, a full Diplomatic Conference was held simultaneously with the 20th (extraordinary) Session of the ICAO Assembly held in Rome from 28 August to 21 September 1973, but it did not provide any effective outcome. As a result, States had to take steps on their own through tougher regulations for airports and bilateral negotiations to drop significantly the number of hijackings.


The 56th plenary meeting of the 32nd United Nations General Assembly adopted on 3 November 1977 another resolution (A/RES/32/8) on the Safety of International Civil Aviation. Reaffirming its condemnation of acts of aerial hijacking, it called upon all states to take all necessary steps to prevent. such acts, including the improvement of security arrangements at airports or by airlines as well as the exchange of relevant information and called upon ICAO to undertake urgently further efforts with a view to ensuring the security of air travel and preventing the recurrence of the acts mentioned.


The Lockerbie disaster on 21 December 1988 drew urgent attention to the danger of plastic explosives for aviation. On 30 January 1989, the ICAO Council established an Ad hoc Group of Experts on the Detection of Explosives. At the 27th Session of the ICAO Assembly held in 1989, a proposal was made to draft an international instrument on the marking of plastic explosives. A special Sub-Committee of the Legal Committee prepared a preliminary draft in 1990 and a Diplomatic Conference met at Montréal from 11 February to 1 March 1991 to adopt the Convention for the Marking of Plastic Explosives for the Purpose of Detection. It entered into force on 26 June 1998.


The Diplomatic Conference on Aviation Security held from 30 August to 10 September 2010 at Beijing adopted two international air law instruments for the suppression of unlawful acts relating to civil aviation: the Convention on the Suppression of Unlawful Acts Relating to International Civil Aviation (prevailing over the above-mentioned Montréal Convention of 23 September 1971 and the Protocol done at Montréal on 23 September 1971 and signed on 24 February 1988) and the Protocol Supplementary to the Convention for the Suppression of Unlawful Seizure of Aircraft (supplementing the above-mentioned Convention signed at The Hague on 16 December 1970), both done on 10 September 2010. By Resolution A39-10 in 2016, the ICAO Assembly urged all States to sign and ratify this instrument. Pursuant to the ratification by the Government of Turkey, the Beijing Convention on the Suppression of Unlawful Acts Relating to International Civil Aviation entered into force on 1 July 2018. The Beijing 2010 instruments are intended to provide an international legal framework for States to respond to new and emerging threats to aviation security and safety. In particular by criminalizing those new acts, the Beijing instruments strengthen the capacity of States to prevent the commission of these offences, and to prosecute and punish those who commit such offenses wherever in the world they occur.


From 26 March to 4 April 2014, under the auspices of ICAO, an International Conference on Air Law was held in Montréal to consider amending the 1963 Tokyo Convention. This Conference was attended by a total of 422 participants from 100 ICAO Member States and nine international organizations and institutions. It was the culmination of a four-year effort to modernize the Tokyo instrument, the new Protocol (Protocol to amend the Convention on Offenses and Certain Other Acts Committed on Board Aircraft) addresses what had become recognized in recent years as a troubling escalation in the frequency of incidents involving disruptive and unruly passengers on scheduled commercial flights. The Protocol enables States to curb the escalation of the severity and frequency of incidents of unruly behavior by passengers onboard aircraft. ICAO Council President, Dr. Olumuyiwa Benard Aliu, made the following comments:” This new Protocol to the Tokyo Convention significantly improves the ability of ICAO Member States to expand jurisdiction over related offenses to the State of the Operator and the State of Landing. It will also serve to enhance global aviation security provisions by expressly extending legal recognition and protections to in-flight security officers (IFSOs) from this point forward.”


The rise of aviation security gave ICAO a new relevance and importance at the international level. Moreover, some endless political debates quickly dissipated with the advent of hijacking and sabotage. The legal instruments on aviation security, complemented by International Standards and Recommended Practices on the subject (Annex 17), and the implementation of decisions by Members States and other international organizations, have proved to be an effective safeguard of aviation security.



United Nations – 6 November 1971 – First Day Cover with Insert.

Combo stamps and cancels (New York and Montréal).

Commemorating the Pan Am flight from New York to Montréal on 6 November 1971, meant to raise public awareness and lobby influential politicians (i.e. Delegates) from all over the world to ratify the three International Conventions dealing with attacks against aircraft: the 1963 Tokyo Convention, the 1970 The Hague Convention, and the 1971 Montréal Convention.

The UN 11-cent stamp (with UN emblem and globe) was issued on 25 May 1962.

On 13 May 1970, to commemorate the UN 25th anniversary, Canada Post Office issued two stamps (10-cent and 15-cent) symbolically representing a sense of emergence and illustrating the tremendous force and energy being focused towards a unification of the world.




It measures 2½" in diameter x 3/16" thick.

The UN Diplomats were urged by pilots and crewmembers who arranged the trip to Montréal to bring about universal ratification of three international treaties designed to deal with attacks against aircraft:

  1. The 1963 Tokyo Convention on Offences and Certain Other Acts Committed on Board Aircraft;
  2. The 1970 The Hague Convention for the Suppression of Unlawful Seizure of Aircraft; and
  3. The 1971 Montréal Convention for the Suppression of Unlawful Acts against the Safety of Civil Aviation.


The guests of the UN flight (6 November 1971) heard a strong appeal for international legislation and the symbols shown on the medal mean support for international skyjacking treaties: The world (circle) requires more (+) treaties (T).



Meeting of the Legal Subcommittee in Washington from 4 to 15 September 1972.

Delegates (from left to right: Charles Brower, Arnold W.G. Kean, and G.E. Vilkov, from USA, Great Britain and USSR respectively) listen to speeches.



Montréal, CANADA – 12 February to 1 March 1991

Commemorative cover - Diplomatic Conference on International Air Law which adopted

the Convention on the Marking of Plastic Explosives for the Purpose of Detection.

The opening of this Conference coincided with the visit of the UN Secretary General (Javier Pérez de Cuéllar) at ICAO Headquarters.