Flight number
From Wikipedia, the free encyclopedia
A flight number, when combined with the name of the airline and the date, identifies a particular flight. This should not be confused with the tail number of the aircraft. 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 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. 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. For example, British Airways flight 1 was the early morning supersonic Concorde service from London to New York City, and Air Canada flight 1 is the daily nonstop service from Toronto to Tokyo. 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.
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.
