Flight number
Encyclopedia
A flight number, when combined with the name of the airline
and the date, identifies a particular flight. This callsign should not be confused with the tail number
of the aircraft
, although both can be used as a call-sign as used in general aviation
. A particular aircraft may fly several different flights in one day, and different aircraft may be used for the same flight number on successive days.
A number of conventions have been developed for defining flight numbers, although these vary widely from airline to airline. Eastbound and northbound flights are traditionally assigned even numbers
, while westbound and southbound flights have odd numbers. Other airlines will use an odd number for an outbound flight and use the next even number for the reverse inbound flight. For destinations served by multiple flights per day, numbers tend to increase during the day. Hence, a flight from point A to point B might be flight 101 and the return flight from B to A would be 102, while the next pair of flights on the same route would usually be assigned codes 103 and 104.
Flight numbers of less than three digits are often assigned to long-haul or otherwise premium flights. Flight number 1 is often used for an airline's "flagship" service. For example, British Airways
flight 1 was the early morning supersonic
Concorde
service from London
to New York City
; Air New Zealand
flight 1 is the daily service from London
to Auckland
via Los Angeles
; and El-Al flight 1 is the daily overnight service from Tel Aviv
to New York City
. Four-digit numbers in the range 1000-4999 typically represent regional affiliate flights, while numbers larger than 5000 are generally codeshare
numbers for flights operated by entirely different airlines or even railways
.
Likewise, flight numbers larger than 9000 are usually referred to ferry flights
, that carry no passengers and are only to move an aircraft from point A to point B, where it is supposed to start a new commercial flight. Flight numbers starting with 8 are often used for charter flights, but it always depends on the commercial carrier choice.
Flight numbers are often taken out of use after a crash or a serious incident. For example, following the crash of Alaska Airlines Flight 261
, the airline changed the flight number for subsequent flights following the same route to 295. Also, American Airlines Flight 77
, which regularly flew from Dulles International Airport in Washington, DC, to Los Angeles International Airport
, was changed to Flight 149 after the September 11, 2001 attacks
.
Note that, although 'flight number' is the term used colloquially, the official term as defined in the Standard Schedules Information Manual (SSIM) published annually by the International Air Transport Association
(IATA) Schedules Information Standards Committee (SISC), is flight code. Officially the term 'flight number' refers to the numeric part (up to four digits) of a flight code. For example, in the flight codes BA2490 and BA2491A, "2490" and "2491" are flight numbers. Even within the airline and airport industry it is common to use the colloquial term rather than the official term.
Flight numbers are also sometimes used for spacecraft, though a flight number for an expendable rocket (say, Ariane 5 Flight 501
) might more reasonably be called the serial number
of the vehicle used, since an expendable rocket can only be launched once. Space Shuttle launches get numbers with the prefix STS
, for example, STS-93
.
Airline
An airline provides air transport services for traveling passengers and freight. Airlines lease or own their aircraft with which to supply these services and may form partnerships or alliances with other airlines for mutual benefit...
and the date, identifies a particular flight. This callsign should not be confused with the tail number
Aircraft registration
An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...
of the aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
, although both can be used as a call-sign as used in general aviation
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...
. A particular aircraft may fly several different flights in one day, and different aircraft may be used for the same flight number on successive days.
A number of conventions have been developed for defining flight numbers, although these vary widely from airline to airline. Eastbound and northbound flights are traditionally assigned even numbers
Even and odd numbers
In mathematics, the parity of an object states whether it is even or odd.This concept begins with integers. An even number is an integer that is "evenly divisible" by 2, i.e., divisible by 2 without remainder; an odd number is an integer that is not evenly divisible by 2...
, while westbound and southbound flights have odd numbers. Other airlines will use an odd number for an outbound flight and use the next even number for the reverse inbound flight. For destinations served by multiple flights per day, numbers tend to increase during the day. Hence, a flight from point A to point B might be flight 101 and the return flight from B to A would be 102, while the next pair of flights on the same route would usually be assigned codes 103 and 104.
Flight numbers of less than three digits are often assigned to long-haul or otherwise premium flights. Flight number 1 is often used for an airline's "flagship" service. For example, British Airways
British Airways
British Airways is the flag carrier airline of the United Kingdom, based in Waterside, near its main hub at London Heathrow Airport. British Airways is the largest airline in the UK based on fleet size, international flights and international destinations...
flight 1 was the early morning supersonic
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...
Concorde
Concorde
Aérospatiale-BAC Concorde was a turbojet-powered supersonic passenger airliner, a supersonic transport . It was a product of an Anglo-French government treaty, combining the manufacturing efforts of Aérospatiale and the British Aircraft Corporation...
service from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
; Air New Zealand
Air New Zealand
Air New Zealand Limited is the national airline and flag carrier of New Zealand. Based in Auckland, New Zealand, the airline operates scheduled passenger flights to 26 domestic destinations and 24 international destinations in 15 countries across Asia, Europe, North America and Oceania, and is...
flight 1 is the daily service from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to Auckland
Auckland
The Auckland metropolitan area , in the North Island of New Zealand, is the largest and most populous urban area in the country with residents, percent of the country's population. Auckland also has the largest Polynesian population of any city in the world...
via Los Angeles
Los Ángeles
Los Ángeles is the capital of the province of Biobío, in the commune of the same name, in Region VIII , in the center-south of Chile. It is located between the Laja and Biobío rivers. The population is 123,445 inhabitants...
; and El-Al flight 1 is the daily overnight service from Tel Aviv
Tel Aviv
Tel Aviv , officially Tel Aviv-Yafo , is the second most populous city in Israel, with a population of 404,400 on a land area of . The city is located on the Israeli Mediterranean coastline in west-central Israel. It is the largest and most populous city in the metropolitan area of Gush Dan, with...
to New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
. Four-digit numbers in the range 1000-4999 typically represent regional affiliate flights, while numbers larger than 5000 are generally codeshare
Code sharing
A codeshare agreement, sometimes simply codeshare, is an aviation business arrangement where two or more airlines share the same flight. A seat can be purchased on one airline but is actually operated by a cooperating airline under a different flight number or code...
numbers for flights operated by entirely different airlines or even railways
High-speed rail
High-speed rail is a type of passenger rail transport that operates significantly faster than the normal speed of rail traffic. Specific definitions by the European Union include for upgraded track and or faster for new track, whilst in the United States, the U.S...
.
Likewise, flight numbers larger than 9000 are usually referred to ferry flights
Dead mileage
Dead mileage, dead running or dead heading, in public transport, describes a practice of non-revenue running, especially in bus transport.- Causes :...
, that carry no passengers and are only to move an aircraft from point A to point B, where it is supposed to start a new commercial flight. Flight numbers starting with 8 are often used for charter flights, but it always depends on the commercial carrier choice.
Flight numbers are often taken out of use after a crash or a serious incident. For example, following the crash of Alaska Airlines Flight 261
Alaska Airlines Flight 261
Alaska Airlines Flight 261, a McDonnell Douglas MD-83 aircraft, experienced a fatal accident on January 31, 2000 at the Pacific Ocean about 2.7 miles north of Anacapa Island, California. The two pilots, three cabin crewmembers, and 83 passengers on board were killed and the aircraft was destroyed...
, the airline changed the flight number for subsequent flights following the same route to 295. Also, American Airlines Flight 77
American Airlines Flight 77
American Airlines Flight 77 was American Airlines' daily scheduled morning transcontinental flight, from Washington Dulles International Airport, in Dulles, Virginia to Los Angeles International Airport in Los Angeles, California...
, which regularly flew from Dulles International Airport in Washington, DC, to Los Angeles International Airport
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...
, was changed to Flight 149 after the September 11, 2001 attacks
September 11, 2001 attacks
The September 11 attacks The September 11 attacks The September 11 attacks (also referred to as September 11, September 11th or 9/119/11 is pronounced "nine eleven". The slash is not part of the pronunciation...
.
Note that, although 'flight number' is the term used colloquially, the official term as defined in the Standard Schedules Information Manual (SSIM) published annually by the International Air Transport Association
International Air Transport Association
The International Air Transport Association is an international industry trade group of airlines headquartered in Montreal, Quebec, Canada, where the International Civil Aviation Organization is also headquartered. The executive offices are at the Geneva Airport in SwitzerlandIATA's mission is to...
(IATA) Schedules Information Standards Committee (SISC), is flight code. Officially the term 'flight number' refers to the numeric part (up to four digits) of a flight code. For example, in the flight codes BA2490 and BA2491A, "2490" and "2491" are flight numbers. Even within the airline and airport industry it is common to use the colloquial term rather than the official term.
Flight numbers are also sometimes used for spacecraft, though a flight number for an expendable rocket (say, Ariane 5 Flight 501
Ariane 5 Flight 501
Cluster was a constellation of four European Space Agency spacecraft which were launched on the maiden flight of the Ariane 5 rocket, Flight 501, and subsequently lost when that rocket failed to achieve orbit. The launch, which took place on Tuesday, June 4, 1996, ended in failure due to an error...
) might more reasonably be called the serial number
Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...
of the vehicle used, since an expendable rocket can only be launched once. Space Shuttle launches get numbers with the prefix STS
Space Shuttle program
NASA's Space Shuttle program, officially called Space Transportation System , was the United States government's manned launch vehicle program from 1981 to 2011...
, for example, STS-93
STS-93
STS-93 marked the 95th launch of the Space Shuttle, the 26th launch of Columbia, and the 21st night launch of a Space Shuttle. Eileen Collins became the first female shuttle Commander on this flight. Its primary payload was the Chandra X-ray Observatory. It would also be the last mission of...
.