The ICAO should not be confused with the International Air Transport Association ( IATA ), a trade organization for airlines also headquartered in Montreal, or with the Civil Air Navigation Services Organisation ( CANSO ), an organization for Air Navigation Service Providers ( ANSPs ) with its headquarters at Amsterdam Airport Schiphol in the Netherlands.

The ICAO also standardizes certain functions for use in the airline industry, such as the Aeronautical Message Handling System ( AMHS ), making it a standards organization.

The 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.

ICAO also assigns 3-letter airline codes ( vs. the more-familiar 2-letter IATA codes — for example, UAL vs. UA for United Airlines ).

ICAO is also responsible for issuing alphanumeric aircraft type codes containing two to four characters.

The NATO phonetic alphabet, more accurately known as the International Radiotelephony Spelling Alphabet and also called the ICAO phonetic or ICAO spelling alphabet, as well as the ITU phonetic alphabet, is the most widely used spelling alphabet.

San Luis Obispo County Regional Airport ( IATA: SBP, ICAO: KSBP, FAA LID: SBP ), also known as McChesney Field, is an airport located in San Luis Obispo, California serving San Luis Obispo County.

* Carbon County Airport, also known as PUC ( IATA code ) and KPUC ( ICAO code )

; LS: ICAO airport code or nationality letters for location indicator ( see also: List of airport codes: LS )

It will also use the letters EDDB, the current code for Berlin Schönefeld Airport, as its ICAO code.

Because of their isolation and difficulty of access, there are no human settlements on these islands, but a detachment of the Chilean Navy is stationed on Isla San Félix, which also hosts a runway ( ICAO code for the airfield: SCFX ).

ICAO codes are also used to identify other aviation facilities such as weather stations, International Flight Service Stations or Area Control Centers, whether or not they are located at airports.

Lalibela is also home to an airport ( ICAO code HALL, IATA LLI ), a large market, two schools and a hospital.

* China Southern Airlines, China, CSN is also their ICAO airline designator

Sibulan Airport ( IATA: DGT, ICAO: RPVD ) also known as Dumaguete Airport.

The airport facilities are also known as Istres-Le Tubé ( ICAO airport code: LFMI ).

* LEAP is also the ICAO code for Empuriabrava Airfield at Girona province in Spain.

The town is also home to an airport ( ICAO code HAGN, IATA GDQ ), and Gondar University which includes Ethiopia's main faculty of medicine.

The airport also attempts to adhere to the air transport standards established by the International Civil Aviation Organization ( ICAO ).

The Convention on International Civil Aviation, also known as the Chicago Convention, established the International Civil Aviation Organization ( ICAO ), a specialized agency of the United Nations charged with coordinating and regulating international air travel.

As more advanced communications methods, such as teleprinter and satellite, took over, the number of such stations diminished, but another type appeared that transmitted spoken and also seemingly random number and letter groups, the latter usually using words from a radio alphabet such as ICAO / NATO alphabet.

Northeim also provides a small grass airfield ( ICAO locator code: EDVN ) due east of the town.

Show Low Regional Airport ( IATA: SOW, ICAO: KSOW ) provides passenger airline service through Great Lakes Airlines to Phoenix and to Denver through Farmington, New Mexico ; the airport maintains a single passenger terminal for this purpose.

Kota Kinabalu International Airport ( KKIA ) ( ICAO Code: WBKK ) provides flights linking the city with other domestic and international destinations.

This has become much more important following JAA, FAA and ICAO rulings on the fitting of intruder resistant flight deck doors and provides a solid basis for decision making in critical and life threatening situations.

The ICAO provides a supplement to Annex 7 which provides an updated list of approved Nationality and Common Marks used by various countries.

The three-letter designators are listed in ICAO Doc 8585 — Designators for Aircraft Operating Agencies, Aeronautical Authorities and Services.

* Aircraft Classification Number, ICAO standard number indicating the pavement load imposed by an aircraft

ICAO maintains the standards for aircraft registration (" tail numbers "), including the alphanumeric codes that identify the country of registration.

* List of aircraft manufacturers by ICAO name

In some states a form of separation is provided to certain aircraft in uncontrolled airspace as far as is practical ( often known under ICAO as an advisory service in class G airspace ), but separation is not mandated nor widely provided.

After initially using the " CACTUS " callsign for the west fleet and " USAIR " for the east fleet, all aircraft began flying under a single " CACTUS " callsign and ICAO code " AWE " in September 2008.

The airline started operations on 11 April 1987, launched by the Owners Abroad Group under the name Air 2000 ( ICAO: AMM ), with two Boeing 757 aircraft and a flight from Manchester to Málaga.

According to the International Civil Aviation Organization ( ICAO ) a runway is a " defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft ".

This will allow ICAO radio stations in the Western Hemisphere to tell the US what has happened to the aircraft instead of the US trying to " sell " the incident.

; HB: ICAO aircraft registration prefix ( since 1935, before: CH )

Radio-navigation aids must keep a certain degree of accuracy ( set by international standards of CAST / ICAO ); to assure this is the case, flight inspection organizations periodically check critical parameters with properly equipped aircraft to calibrate and certify ILS precision.

An investigation commission of the ICAO determined that a bomb placed in a container in location 13-R in the forward cargo hold caused the destruction of the aircraft.

In 1946, she became the first woman to serve as Technical Advisor for ICAO, where she helped to draft International Air Worthiness regulations for the design and production of commercial aircraft.

* Belgium, OO ( Oscar, Oscar ), ICAO aircraft registration prefix

* Regional commuter airline ( carriers ) fly and operate with their own ICAO or IATA codes, their own call sign, with a fleet of aircraft with 9-19 passenger seats, no flight attendant, non-stand up cabins, and function with or without an individual identity and brand, even though an individually operating certificated regional airline company.

* Regional feeder-airline ( carriers ) fly and operate with their own ICAO or IATA codes, their own call sign, and fly and operate aircraft with 9-99 passenger seats, without an individual corporate identity or brand, even though an individually operating certificated regional feeder airline company.

* Regional airline carriers are federally operating certificated airlines which operate their own fleet of aircraft with their own brand, ICAO or IATA code, and their own call sign, upon a fleet of aircraft with 9-99 seats and always include at least one fleet of aircraft which requires a flight attendant.

* Airline carriers operate their own fleet of aircraft with their own brand and identity, ICAO or IATA code, and their own call sign.

* Major airline carriers operate their own fleet of aircraft with their own brand and identity, ICAO or IATA code, their own call sign, and operate at least one fleet of aircraft with more than 99 passengers upon their federal operating certificate.

The Cheboksary Airport ( IATA CSY, ICAO UWKS, international airport since 1995 ) receives both cargo and passenger aircraft of practically all types and sizes.