|Formation||April 4, 1944|
|Type||United Nations Specialised Agency|
|Secretary-General of the International Civil Aviation Organization |
|United Nations Economic and Social Council|
The International Civil Aviation Organization (ICAO; French: Organisation de l'aviation civile internationale), is a specialized agency of the United Nations. It codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth.  Its headquarters is located in the Quartier International of Montreal, Quebec, Canada.
The ICAO Council adopts standards and recommended practices concerning air navigation, its infrastructure, flight inspection, prevention of unlawful interference, and facilitation of border-crossing procedures for international civil aviation. ICAO defines the protocols for air accident investigation followed by transport safety authorities in countries signatory to the Chicago Convention on International Civil Aviation.
The Air Navigation Commission (ANC) is the technical body within ICAO. The Commission is composed of 19 Commissioners, nominated by the ICAO's contracting states, and appointed by the ICAO Council.  Commissioners serve as independent experts, who although nominated by their states, do not serve as state or political representatives. The development of international Standards And Recommended Practices is done under the direction of the ANC through the formal process of ICAO Panels. Once approved by the Commission, standards are sent to the Council, the political body of ICAO, for consultation and coordination with the Member States before final adoption.
ICAO is distinct from other international air transport organizations, like the International Air Transport Association (IATA), a trade association representing airlines; the Civil Air Navigation Services Organization (CANSO), an organization for Air navigation service providers (ANSPs); and the Airports Council International, a trade association of airport authorities.
- 1 History
- 2 Statute
- 3 Membership
- 4 Council
- 5 Standards
- 6 Registered codes
- 7 Regions and regional offices
- 8 Leadership
- 9 Climate change
- 10 Investigations of air disasters
- 11 Drone regulations and registration
- 12 See also
- 13 References
- 14 External links
The forerunner to ICAO was the International Commission for Air Navigation (ICAN).  It held its first convention 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, 27 countries attended. The third convention, held in London in 1912 allocated the first radio callsigns for use by aircraft. ICAN continued to operate until 1945.  
Fifty-two countries signed the Chicago Convention on International Civil Aviation, also known as the Chicago Convention, in Chicago, Illinois, on 7 December 1944. Under its terms, a Provisional International Civil Aviation Organization (PICAO) was to be established, to be replaced in turn by a permanent organization when 26 countries ratified the convention. Accordingly, PICAO began operating on 6 June 1945, replacing ICAN. The 26th country ratified the Convention on 5 March 1947 and, consequently PICAO was disestablished on 4 April 1947 and replaced by ICAO, which began operations the same day. In October 1947, ICAO became an agency of the United Nations linked to the United Nations Economic and Social Council (UNESCO).  
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 cover all moving expenses, stating that Montreal "was too far from Europe and Asia", "had cold winters," was hard to attend due to the refusal of the Canadian government to provide visas in a timely manner, and that the taxes imposed on ICAO by Canada were too high.  According to The Globe and Mail, Qatar's move was at least partly motivated by the pro-Israel foreign policy of Canadian Prime Minister Stephen Harper.   Approximately one 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.   
The 9th edition of the Convention on International Civil Aviation includes modifications from 1948 up to year 2006. ICAO refers to its current edition of the Convention as the Statute, and designates it as ICAO Document 7300/9. The Convention has 19 Annexes that are listed by title in the article Convention on International Civil Aviation. 
The Republic of China was a founding member of ICAO but was replaced by People's Republic of China as the legal representative of China in 1971 and as such, did not take part in the organization. In 2013, the Republic of China was for the first time invited to attend 38th session of ICAO Assembly as a guest under the name of Chinese Taipei.
The Council of ICAO is elected by the Assembly every 3 years and consists of 36 members elected in 3 groups. The present Council was elected on 4 October 2016 at the 39th Assembly of ICAO at Montreal.  The structure of the present Council is as follows:
Group I (States of chief importance in air transport)
- People's Republic of China
- Russian Federation
- United Kingdom of Great Britain and Northern Ireland
- United States of America
Group II (States which make the largest contribution to the provision of facilities for international civil air navigation)
- Saudi Arabia
- South Africa
Group III (States ensuring geographic representation)
- Cape Verde
- Republic of Korea
- United Arab Emirates
- United Republic of Tanzania
Each country should have an accessible Aeronautical Information Publication (AIP), based on standards defined by ICAO, containing information essential to air navigation. Countries are required to update their AIP manuals every 28 days and so provide definitive regulations, procedures and information for each country about airspace and airports. ICAO's standards also dictate that temporary hazards to aircraft are regularly published using NOTAMs.
ICAO defines an International Standard Atmosphere (also known as ICAO Standard Atmosphere), a model of the standard variation of pressure, temperature, density, and viscosity with altitude in the Earth's atmosphere. This is useful in calibrating instruments and designing aircraft. 
ICAO standardizes machine-readable passports worldwide.  Such passports have an area where some of the information otherwise written in textual form is written as strings of alphanumeric characters, printed in a manner suitable for optical character recognition. This enables border controllers and other law enforcement agents to process such passports quickly, without having to enter the information manually into a computer. ICAO publishes Document 9303 Machine Readable Travel Documents, the technical standard for machine-readable passports.  A more recent standard is for 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 smartcards. Like some smartcards, 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.
ICAO is active in infrastructure management, including Communication, navigation and surveillance / Air Traffic Management (CNS/ATM) systems, which employ digital technologies (like satellite systems with various levels of automation) in order to maintain a seamless global air traffic management system. 
|1||< 800 m (2,625 ft)|
|2||800–1,200 m (2,625–3,937 ft)|
|3||1,200–1,800 m (3,937–5,906 ft)|
|4||≥ 1,800 m (5,906 ft)|
|Letter||Wingspan||Main Gear span||Airbus ||Boeing |
|A||< 15 metres (49.2 ft)||< 4.5 metres (14.8 ft)|
|B||15 metres (49.2 ft) – < 24 metres (78.7 ft)||4.5 metres (14.8 ft) – < 6 metres (19.7 ft)|
|C||24 metres (78.7 ft) – < 36 metres (118.1 ft)||6 metres (19.7 ft) – < 9 metres (29.5 ft)||A320 Family||B717, B727, B737|
|D||36 metres (118.1 ft) – < 52 metres (170.6 ft)||9 metres (29.5 ft) – < 14 metres (45.9 ft)||A300/ A310||B707, B757, B767|
|E||52 metres (170.6 ft) – < 65 metres (213.3 ft)||9 metres (29.5 ft) – < 14 metres (45.9 ft)||A330/ A340, A350||B747, B777, B787|
|F||65 metres (213.3 ft) – < 80 metres (262.5 ft)||14 metres (45.9 ft) – < 16 metres (52.5 ft)||A380||B747-8|
Both ICAO and IATA have their own airport and airline code systems. 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 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 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.) Note that not all airports are assigned codes in both systems; for example, airports that do not have airline service do not need an IATA code.
ICAO also assigns 3-letter airline codes (versus the more-familiar 2-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  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.
ICAO maintains the standards for aircraft registration ("tail numbers"), including the alphanumeric codes that identify the country of registration. For example, airplanes registered in the United States have tail numbers starting with N.
ICAO is also responsible for issuing alphanumeric aircraft type codes containing two to four characters. These codes provide the identification that is typically used in flight plans. The Boeing 747 would use B741, B742, B743, etc., depending on the particular variant.
ICAO has a headquarters, seven regional offices, and one regional sub-office: 
- Headquarters – Montreal, Quebec, Canada
- Asia and Pacific (APAC) – Bangkok, Thailand; Sub-office – Beijing, China
- Eastern and Southern African (ESAF) – Nairobi, Kenya
- Europe and North Atlantic (EUR/NAT) – Paris, France
- Middle East (MID) – Cairo, Egypt
- North American, Central American and Caribbean (NACC) – Mexico City, Mexico
- South American (SAM) – Lima, Peru
- Western and Central African (WACAF) – Dakar, Senegal
|Secretary||Country of Nationality||Term|
|Fang Liu||China||2015–present |
|Renato Claudio Costa Pereira||Brazil||1997–2003|
|Shivinder Singh Sidhu||India||1988–1991|
|Bernardus Tielman Twigt||Netherlands||1964–1970|
|Ronald MacAllister Macdonnell||Canada||1959–1964|
|President||Country of Nationality||Term|
|Olumuyiwa Benard Aliu||Nigeria||2013–present|
|Roberto Kobeh Gonzalez||Mexico||2006–2013|
|Edward Pearson Warner||United States||1947–1957|
This section's factual accuracy may be compromised due to out-of-date information. (February 2009)
Emissions from international aviation are specifically excluded from the targets agreed under the Kyoto Protocol. Instead, the Protocol invites developed countries to pursue the limitation or reduction of emissions through the International Civil Aviation Organization. ICAO's environmental committee continues to consider the potential for using market-based measures such as trading and charging, but this work is unlikely to lead to global action. It is currently developing guidance for states who wish to include aviation in an emissions trading scheme (ETS) to meet their Kyoto commitments, and for airlines who wish to participate voluntarily in a trading scheme.
Emissions from domestic aviation are included within the Kyoto targets agreed by countries. This has led to some national policies such as fuel and emission taxes for domestic air travel in the Netherlands and Norway, respectively. Although some countries tax the fuel used by domestic aviation, there is no duty on kerosene used on international flights. 
On October 6, 2016, the ICAO finalized an agreement among its 191 member nations to address the more than t 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 does 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. 1000  NGO reaction to the deal was mixed.   
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.   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.  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.  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." 
Most air accident investigations are carried out by an agency of a country that is associated in some way with the accident. For example, the Air Accidents Investigation Branch conducts accident investigations on behalf of the British Government. ICAO has conducted four investigations involving air disasters, of which two were passenger airliners shot down while in international flight over hostile territory.
- Libyan Arab Airlines Flight 114 which was shot down on 21 February 1973 by Israeli F-4 jets over the Sinai Peninsula during a period of tension that led to the Arab-Israeli Yom Kippur War killing 108 people.
- Korean Air Lines Flight 007, which was shot down on 1 September 1983 by a Soviet Su-15 interceptor near Moneron Island just west of Sakhalin Island during a period of heightened Cold War tension killing all 269 people on board including U.S. Representative Larry McDonald. 
- UTA Flight 772, which was destroyed by a bomb on 19 September 1989 above the Sahara Desert in Niger, en route from N'Djamena, Chad, to Paris, France. The explosion caused the aircraft to break up, killing all 156 passengers and 15 crew members, including the wife of U.S. Ambassador Robert L. Pugh. Investigators determined that a bomb placed in the cargo hold by Chadian rebels backed by Libya was responsible for the explosion. A French court convicted in absentia six Libyans of planning and implementing the attack. 
- The 1996 shootdown of Brothers to the Rescue aircraft on 24 February 1996, when two civilian aircraft operating north of Cuba were shot down by two jets of the Cuban Air Force. The Cuban military alleged that aircraft operated by the group Brothers to the Rescue had scattered propaganda leaflets onto Cuba prior to the incident, and issued orders that such aircraft be shot down. All four crew members aboard the two aircraft were killed, whilst a third aircraft managed to escape and return to the American mainland.
ICAO is looking at having a singular ledger for drone registration to help law enforcement globally. Currently, ICAO is responsible for creating drone regulations across the globe, and it is expected that it will only maintain the registry. This activity is seen as a forerunner to global regulations on the drone flying from ICAO. 
ICAO currently maintains the 'UAS Regulation Portal'  for various countries to list their country's UAS regulations and also review the best practices from across the globe.
- Aircraft registration
- Airline codes (includes ICAO codes)
- Aviation safety
- Fédération Aéronautique Internationale (FAI)
- Flight planning
- Freedoms of the air
- International Civil Aviation Organization airport code
- International flight
- International Maritime Organization
- Kenneth Macdonald Beaumont
- List of aircraft manufacturers by ICAO name
- NATO phonetic alphabet
- Transportation Security Administration (TSA)
- Federal Aviation Regulations
- Höhne, Sebastian. "IT in general Aviation: Pen and Paper vs. Bits and Bytes" (PDF). hoehne.net. p. 38. Retrieved 5 May 2014.
- "Air Navigation Commission". ICAO. Retrieved 7 August 2013.
- "Registrations". Golden Years of Aviation. Archived from the original on 30 January 2011. Retrieved 11 February 2011.
- "1912 Radio Callsign prefixes". Golden Years of Aviation. Archived from the original on 1 January 2011. Retrieved 11 February 2011.
- "icao.int International Civil Aviation Organization History". Retrieved 28 July 2017.
- Baird fighting 'tooth and nail' to keep UN aviation office in Montreal, CBC News, 2 May 2013.
- Disgruntled Arab states look to strip Canada of UN agency by Campbell Clark, The Globe and Mail, 2 May 2013.
- Canada now paying the price for Baird's misstep into East Jerusalem by Michael Bell, Special to The Globe and Mail, 6 May 2013.
- ICAO stays in Montreal after Qatar stumbles Archived 3 June 2013 at the Wayback Machine. by François Shalom, The Montreal Gazette, 24 May 2013.
- "Lobbying saved Montreal's UN aviation agency, Paradis says". CBC News. 24 May 2013. Retrieved 24 May 2013.
- Qatar Withdraws Offer to Host ICAO Permanent Seat, ICAO Newsroom, 24 May 2013.
- "Annex 19 on Security Management". Archived from the original on 10 December 2013. Retrieved 31 May 2017.
- "Member States" (PDF). ICAO. Retrieved 2017-07-19.
- South Sudan becomes 191st member of ICAO – Sudan Tribune: Plural news and views on Sudan. Sudan Tribune. Retrieved on 2013-07-12. Archived 23 March 2015 at the Wayback Machine.
- "Member States.English.pdf" (PDF). ICAO. Retrieved 2014-07-20. The Minister of Switzerland made the following statement in the note transmitting the Swiss Instrument of Ratification: "My Government has instructed me to notify you that the authorities in Switzerland have agreed with the authorities in the Principality of Liechtenstein that this Convention will be applicable to the territory of the Principality as well as to that of the Swiss Confederation, as long as the Treaty of 29 March 1923 integrating the whole territory of Liechtenstein with the Swiss customs territory will remain in force".
- "ICAO Assembly elects new Council for three-year term". www.icao.int.
- Manual of the ICAO Standard Atmosphere: extended to 80 kilometres (262,500 feet) (in English, French, Spanish, and Russian) (3rd ed.). Montreal: ICAO. 1993. ISBN 92-9194-004-6. Archived from the original (CD-ROM) on 6 December 2012. Retrieved 6 September 2012.
- "Welcome to the ICAO Machine Readable Travel Documents Programme". ICAO. Retrieved 2012-09-06.
- Machine Readable Travel Documents, Document 9303 (Sixth ed.). ICAO. 2006. Retrieved 2013-08-09.
- "Infrastructure Management". ICAO. Retrieved 2012-09-06.
- ICAO Annex 14 — Aerodromes
- "ICAO Aerodrome Reference Code, FAA Airplane Design Group and Aircraft Approach Category for Airbus Aircraft" (PDF). Airbus. May 2015.
- "Boeing Commercial Aircraft - Design Groups/Codes (FAA & ICAO)" (PDF). Boeing. November 4, 2014.
- "Archived copy". Archived from the original on 16 April 2010. Retrieved 27 March 2010.
- "Contact Us". ICAO. Retrieved 2012-09-06.
- "Dr. Fang Liu of China Becomes First-Ever Woman Appointed Secretary General of ICAO". ICAO. March 11, 2015. Retrieved July 4, 2017.
- "Climate Change: Aviation Emissions, an ignored but fast growing problem" (PDF). greenskies.org. 2005. Retrieved 3 August 2011.
- Gill, Michael. "Preparing for CORSIA Take-Off" (PDF). IETA.org. Retrieved 19 September 2017.
- Milman, Oliver (6 October 2016). "First deal to curb aviation emissions agreed in landmark UN accord". The Guardian. London, United Kingdom. Retrieved 2016-10-20.
- Henry Fountain (September 25, 2016). "'Aviation's Paris Moment' as Nations Near Emissions Deal". NYT. Retrieved September 26, 2016.
- Henry Fountain (October 6, 2016). "Over 190 Countries Adopt Plan to Offset Air Travel Emissions". NYT. Retrieved October 7, 2016.
- UN aviation pact will not be aligned with Paris climate goals, M. Darby, Climate Change News, 6 October 2016.
- The new UN deal on aviation emissions leaves much to be desired, D. Hodgkinson & R. Johnston. The Conversation, 10 October 2016.
- Weak Market-based Measure Allows Airplanes' Greenhouse Pollution to Triple, press release by Center for Biological Diversity and Friends of the Earth. 6 October 2016.
- Green Groups Warn Deal to Lower Aviation Pollution is 'Weak Shell Game', N. Prupis, Common Dreams, 6 October 2016
- David Pearson (1987). KAL 007: Cover-up. New York: Summit Books. p. 266. ISBN 978-0-671-55716-4.
- Ranter, Harro. "ASN Aircraft accident McDonnell Douglas DC-10-30 N54629 Ténéré desert". aviation-safety.net. Retrieved 31 May 2017.
- "UN proposes global database for drone registration". Geospatial World. 2017-10-06. Retrieved 2017-10-06.
- "UAS Regulation Portal". www.icao.int. Retrieved 2017-10-06.
- Official website of the International Civil Aviation Organization
- Convention on International Civil Aviation – Document 7300
- ECCAIRS 4.2.8 Data Definition Standard – Location Indicators by State, 17 Sep 2010
- ICAO Aircraft and Manufacturer Codes – Document 8643
- The Postal History of the International Civil Aviation Organization (ICAO)
- ICAO Will Mute Mics At Mention of Taiwan: Paraguay Official