International Civil Aviation Organization

20th century

In the early 20th Century, the International Telecommunication Union met to discuss and implement one of the first internationally agreed upon standards relating to aviation, country-specific prefixes for aircraft callsigns. The first convention was held in 1903 in Berlin, Germany, but no agreements were reached among the eight countries that attended. At the second convention in 1906, also held in Berlin, twenty-seven countries attended.^[6] The third convention, held in London in 1912, allocated the first radio callsigns for use by aircraft. Following this, at the Paris Convention of 1919, a forerunner to ICAO named ICAN was established, the International Commission for Air Navigation. ICAN continued to operate until 1945.^[7][8]

The Convention on International Civil Aviation, also known as the Chicago Convention, in Chicago, was signed by 52 countries on 7 December 1944. Under its terms, a Provisional International Civil Aviation Organization was to be established, to be replaced in turn by a permanent organization when twenty-six countries ratified the convention. PICAO began operating on 6 June 1945, replacing ICAN. The 26th country ratified the convention on 5 March 1947 and, consequently, PICAO held its last session from 29 April 1947 until 7 May 1947, with the Convention on International Civil Aviation coming into force on 4 April 1947.^[9]

In October 1947, ICAO became an agency of the United Nations under its Economic and Social Council (ECOSOC).^[7][10]

21st century

In April 2013, Qatar offered to serve as the new permanent seat of the Organization. Qatar promised to construct a massive new headquarters for ICAO and to cover all moving expenses, stating that Montreal "was too far from Europe and Asia", "had cold winters", was hard to attend due to the Canadian government's slow issuance of visas, and that the taxes imposed on ICAO by Canada were too high.^[11] According to The Globe and Mail, Qatar's invitation was at least partly motivated by the pro-Israel foreign policy of Canadian prime minister Stephen Harper.^[12][13] Approximately a month later, Qatar withdrew its bid after a separate proposal to the ICAO's governing council to move the ICAO triennial conference to Doha was defeated by a vote of 22–14.^[14][15][16]

In June 2014, the Montreal Metro station closest to the ICAO headquarters was renamed Square-Victoria–OACI,^[b] celebrating the 70th anniversary of ICAO's presence in Montreal.^[17]

Exclusion of Taiwan

The Republic of China was a founding member of ICAO. Following its retreat to Taiwan, it was eventually replaced by the People's Republic of China as the legal representative of China in 1971.

In 2013, Taiwan was for the first time invited to attend the ICAO Assembly, at its 38th session, as a guest under the name of "Chinese Taipei". As of September 2019^[update], it has not been invited to participate again, due to renewed PRC pressure.^{[32][33][34][35]}

The host government, Canada, supports Taiwan's inclusion in ICAO. Support also comes from Canada's commercial sector with the president of the Air Transport Association of Canada saying in 2019 that "It's about safety in aviation so from a strictly operational and non-political point of view, I believe Taiwan should be there."^[36]

Passport standards

ICAO has published standards for machine-readable passports.^[43] Machine-readable passports have an area where some of the information otherwise written in textual form is also written as strings of alphanumeric characters, printed in a manner suitable for optical character recognition, which enables border controllers and other law enforcement agents to process such passports more quickly without having to enter the information manually into a computer.

ICAO's technical standard for machine-readable passports is contained in Document 9303 Machine Readable Travel Documents.^[44]

A more recent standard covers biometric passports. These contain biometrics to authenticate the identity of travellers. The passport's critical information is stored on a tiny RFID computer chip, much like information stored on smart cards. Like some smart cards, the passport book design calls for an embedded contactless chip that is able to hold digital signature data to ensure the integrity of the passport and the biometric data.

Aerodrome reference code

Airport codes

ICAO uses 4-letter airport codes (vs. IATA's 3-letter codes). The ICAO code is based on the region and country of the airport—for example, Charles de Gaulle Airport has an ICAO code of LFPG, where L indicates Southern Europe, F, France, PG, Paris de Gaulle, while Orly Airport has the code LFPO (the 3rd letter sometimes refers to the particular flight information region (FIR) or the last two may be arbitrary). In most parts of the world, ICAO and IATA codes are unrelated; for example, Charles de Gaulle Airport has an IATA code of CDG. However, the location prefix for the continental United States is K, and ICAO codes are usually the IATA code with this prefix. For example, the ICAO code for Los Angeles International Airport is KLAX. Canada follows a similar pattern, where a prefix of C is usually added to an IATA code to create the ICAO code. For example, Calgary International Airport is YYC or CYYC. (In contrast, airports in Hawaii are in the Pacific region and so have ICAO codes that start with PH; Kona International Airport's code is PHKO. Similarly, airports in Alaska have ICAO codes that start with PA. Merrill Field, for instance is PAMR.) Not all airports are assigned codes in both systems; for example, airports that do not have airline service do not need an IATA code.

Airline codes

ICAO also assigns three-letter airline codes versus the more-familiar two-letter IATA codes—for example, UAL vs. UA for United Airlines. ICAO also provides telephony designators to aircraft operators worldwide, a one- or two-word designator used on the radio, usually, but not always, similar to the aircraft operator name. For example, the identifier for Japan Airlines International is JAL and the designator is Japan Air, but Aer Lingus is EIN and Shamrock. Thus, a Japan Airlines flight numbered 111 would be written as "JAL111" and pronounced "Japan Air One One One" on the radio, while a similarly numbered Aer Lingus would be written as "EIN111" and pronounced "Shamrock One One One". In the US, FAA practices^[48] require the digits of the flight number to be spoken in group format ("Japan Air One Eleven" in the above example) while individual digits are used for the aircraft tail number used for unscheduled civil flights.

Aircraft registrations

ICAO maintains the standards for aircraft registration, including the alphanumeric codes that identify the country of registration.

Aircraft type designators

ICAO is also responsible for issuing two to four character alphanumeric aircraft type designators for those aircraft types which are most commonly provided with air traffic service. These codes provide an abbreviated aircraft type identification, typically used in flight plans. For example, the Boeing 747-100, -200 and -300 are given the type designators B741, B742 and B743 respectively.^[49]

List of secretaries general

More information Secretary, Country of nationality ...

Secretary	Country of nationality	Term
Juan Carlos Salazar Gómez	Colombia	From August 2021
Fang Liu	China	2015 – August 2021[57]
Raymond Benjamin	France	2009–2015
Taïeb Chérif	Algeria	2003–2009
Renato Claudio Costa Pereira	Brazil	1997–2003
Philippe Rochat	Switzerland	1991–1997
Shivinder Singh Sidhu	India	1988–1991
Yves Lambert	France	1976–1988
Assad Kotaite	Lebanon	1970–1976
Bernardus Tielman Twigt	Netherlands	1964–1970
Ronald MacAllister Macdonnell	Canada	1959–1964
Carl Ljungberg	Sweden	1952–1959
Albert Roper	France	1944–1951

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List of council presidents

Carbon Offsetting and Reduction Scheme for International Aviation

On 6 October 2016, the ICAO finalized an agreement among its 191 member nations to address the more than 1000 million tonnes of carbon dioxide emitted annually by international passenger and cargo flights. The agreement will use an offsetting scheme called CORSIA (the Carbon Offsetting and Reduction Scheme for International Aviation) under which forestry and other carbon-reducing activities are directly funded, amounting to about 2% of annual revenues for the sector. Rules against 'double counting' should ensure that existing forest protection efforts are not recycled. The scheme did not take effect until 2021 and will be voluntary until 2027, but many countries, including the US and China, have promised to begin at its 2020 inception date. Under the agreement, the global aviation emissions target is a 50% reduction by 2050 relative to 2005.^[60] NGO reaction to the deal was mixed.^[61][62][63]

The agreement has critics. It is not aligned with the 2015 Paris climate agreement, which set the objective of restricting global warming to 1.5 to 2 °C. A late draft of the agreement would have required the air transport industry to assess its share of global carbon budgeting to meet that objective, but the text was removed in the agreed version.^[64][65] CORSIA will regulate only about 25 percent of aviation's international emissions, since it grandfathers all emissions below the 2020 level, allowing unregulated growth until then.^[66] Only 65 nations will participate in the initial voluntary period, not including significant emitters Russia, India and perhaps Brazil. The agreement does not cover domestic emissions, which are 40% of the global industry's overall emissions.^[65] One observer of the ICAO convention made this summary:

Airline claims that flying will now be green are a myth. Taking a plane is the fastest and cheapest way to fry the planet and this deal won't reduce demand for jet fuel one drop. Instead offsetting aims to cut emissions in other industries,

although another critic called it "a timid step in the right direction."^[67]

ICAO has expressed strong opposition to 2025 proposals from various UN bodies and international organizations, including the International Monetary Fund, suggesting new taxes or levies on international aviation to fund global climate initiatives. ICAO contends that such measures could undermine CORSIA, emphasizing that CORSIA is the sole global framework for addressing international aviation emissions and warning that additional levies could disrupt its implementation and the broader goal of sustainable aviation development. While acknowledging the need for increased climate finance, ICAO urged stakeholders to support existing mechanisms like CORSIA rather than introducing potentially conflicting financial measures.^[68]

Air quality

Emissions limits for aircraft engines are defined by the Annex 16, Volume 2 of the ICAO Technology Standards, they include standards for hydrocarbons, carbon monoxide, NO_x, smoke and particulate matter for local air quality near airports, below 3,000 ft (910 m).^[69] The first ICAO emissions regulation was adopted in 1981, and more stringent NO_x standards were subsequently adopted: CAEP/2 in 1993, CAEP/4 in 1999, CAEP/6 in 2005 and CAEP/8 in 2011.^[69] Higher bypass ratios, lean burn and Rich Quick Quench Lean combustor design can reduce NO_x emissions.^[69]