What’s in a flight number? You may think they’re just arbitrary numbers, but there’s a lot more to it…
Each airline uses a different convention for numbering flights, but there’s almost always a pattern to it. For example, with Qantas flight numbers:
- QF1-199 are Qantas-operated international flights
- QF200-299 are codeshare flights operated by Jetstar
- QF300-399 are international codeshare flights to/from Australia operated by other Qantas partner airlines
- QF400-1399 are Qantas domestic flights
- QF1400-1499 are QantasLink Dash 8 flights (generally between Sydney and VIC/ACT destinations)
- QF1500-1599 are QantasLink Boeing 717 flights between major Australian cities
- QF1600-1999 are other QantasLink jet services on regional routes (mainly within WA)
- QF2000-2899 are QantasLink Dash 8 flights (excluding QF2600-2717)
- QF2600-2717 are codeshare flights operated by Alliance Airlines, Airnorth or Network Aviation
- QF3000-4999 are codeshare flights operated by various international partner airlines
- QF5000-5399 are codeshare flights operated by Jetstar Japan or Jetstar Asia
- QF8000-8999 are codeshare flights operated by Emirates, Air New Zealand, LATAM Airlines or Cathay Pacific
Beyond this, there’s also a convention to the odd & even numbering of Qantas flights.
For international Qantas flights, odd-numbered flights are those departing Australia and even-numbered flights return to Australia. An easy way to remember this is with the saying “it’s odd to leave Australia”.
For domestic Qantas routes, flights operating in a west/south direction have odd numbers. Flights travelling in a east/north direction have even flight numbers.
As for the “QF” code itself, this is the International Air Transport Association (IATA) airline designator code for Qantas Airways Limited.
IATA has also designated Qantas an accounting code of “081”, which is why all Qantas ticket numbers begin with those three digits. The various subsidiaries of the Qantas Group also all have unique three-letter International Civil Aviation Organization (ICAO) codes, which customers generally don’t see. For example, Qantas Airways has the “QFA” code and QantasLink has “QLK”.
Virgin Australia uses a similar convention for odd and even-numbered flights. Virgin flights with an odd number are always travelling north. VA flights with an even number are flying south. This is based on the latitude of the origin and destination airports. For example, VA560 from Perth to Sydney has an even flight number because Perth is ~31 degrees south of the equator, while Sydney is ~33 degrees south.
In general, alternating flight numbers are used for an aircraft’s outbound and return journeys. But there are exceptions. Some U.S. airlines keep the same flight number for on both legs. For example, American Airlines flight AA5079 flies from Charlotte to Bristol, and then back to Charlotte with the same flight number. Until recently, Singapore Airlines also flew a Singapore-Sydney-Canberra-Singapore triangle route which kept its SQ288 flight number for the entire trip.
The same flight number may also be used for multiple legs of a multi-stop journey, like with QF1 from Sydney to London via Singapore. In aviation terms, this is still considered a direct flight because the same flight number is retained for the whole trip (even though it’s not a non-stop flight; there is a subtle yet often misunderstood difference in these definitions).
A particular flight number is not necessarily bound to a particular route for life. For example, QF107 used to be a Qantas flight from Sydney to New York via Los Angeles. It later became a Sydney-Beijing flight, although that route has now been cancelled. Similarly, QF37 switched a few years ago from a Melbourne-Wellington flight to a Melbourne-Singapore route.
Qantas, like many airlines, dedicates its lowest flight numbers to its most prestigious routes. That’s why QF1 has long been the flagship “kangaroo route” between Sydney and London (even though the stopover point has changed over the years from Bangkok, to Singapore, to Dubai and then back to Singapore).
But not every airline does this. With Lufthansa, for example, LH1 is just a regular domestic flight from Hamburg to Frankfurt. Lufthansa’s arguably most prestigious route, from Frankfurt to New York JFK, is LH400.
While many people don’t take much notice of airline flight numbers, some frequent flyers even have favourites. While QF1 is obviously a nice flight number, my personal favourite is LH2222 (a regular flight from Munich to Toulouse). Why? Because when the flight’s ready for boarding, the automated announcement welcomes you to “your Lufthansa Star Alliance flight two-two-two-two to Toulouse”.