What's the use of flight numbers?

[c52]

I used to think that together with a date they identified a flight, yet tomorrow at 00:20Z AA46 flies ORD-LHR, and then later tomorrow, at 23:15Z, AA46 does the same trip.

SQ52 takes 25 hours to fly SIN-MAN-IAH, so two can be airborne at once.

Are they just a relic from simpler days, or do they carry a unique and useful meaning in the world of airline/airport operations?

When I'm flying I look for the STD and destination on the departures board, not the flight no, and similarly with announcements.

[DaveReidUK]

I used to think that together with a date they identified a flight, yet tomorrow at 00:20Z AA46 flies ORD-LHR, and then later tomorrow, at 23:15Z, AA46 does the same trip.

You are almost correct. The combination of a flight number, airport of departure and date (both local and UTC) is supposed to be unique.

If a flight is scheduled to depart twice from the same airport on the same Zulu day, then one of the flights will be identified with a Z suffix on the flight number (not normally shown on flight information displays).

[c52]

and -Y means the flight has been delayed past 00:00Z?

[DaveReidUK]

and -Y means the flight has been delayed past 00:00Z?

Yes, flights delayed from yesterday are typically distinguished by adding a D or Y suffix to avoid confusion with today's flight.

[Peter47]

If you look back half a century or more a flight might have half a dozen or more sectors but it made sense to have a single flight number when they were operated as a through service by (usually) one aircraft. There will certainly have been more than one PA 1 & 2 (their round the world flights), in the air at once, albeit thousands of miles apart.

These days sometimes flights into and out of of a hub operated as separate services by different aircraft can share the same number for marketing purposes, in which case the the continuing flight can leave before the flight into the hub as arrived, albeit with a different ATC flight number.

As I have posted before, I have a strong dislike of the approach adopted by some carriers such as American of giving an inbound and outbound flight, generally operated by the same aircraft, the same number. This can definitely cause confusion when looking up flights using a tracking website.

[GLIDER 90]

Talking of flight numbers did the RAF over the years when attending an airshow in the UK or abroad, use the callsign they flew in with or did they use the aircraft type for the display?

[DaveReidUK]

As I have posted before, I have a strong dislike of the approach adopted by some carriers such as American of giving an inbound and outbound flight, generally operated by the same aircraft, the same number. This can definitely cause confusion when looking up flights using a tracking website.

It's hard to see what other option a carrier like AA has. When you take into account all the codeshare flights that are allocated AA marketing flight numbers, it's likely that there simply aren't enough unique flight numbers to go round.

So it you're going to duplicate flight numbers, you could argue that the least confusing way is to assign them to a given route in both directions. That doesn't break any of the scheduling rules. AA393, for example, operates DFW-MEX and MEX-DFW daily (and uses a different aircraft on each leg).

[Hartington]

Some years ago (at least 10) Delta applied to IATA for a 2nd 2 character code precisely because they were running out of flight numbers.. They were turned down because IATA is running out of two character airline codes. All the xx, xn and nx codes are in use and many have been duplicated (well maybe not all but they keep a few aside for new airlines). The use of three character ICAO codes for reservations might allow airlines to have more than one code but the reservations systems throw their hands up in horror and quote $$$$$$ when the idea is mooted.

My personal view is that code sharing is the problem and since codesharing is very close to fraud it should be banned. I'm amazed the regulatory keep allowing it.

[Ken Borough]

codesharing is very close to fraud

I, and certainly many others, would love to hear your rational point of view! Please tell us.

[DaveReidUK]

AFAIK, pretty well all regulators have strict rules that mean airlines must disclose, at the time of booking, whether a service is operated as a codeshare, for example 49 CFR 41712 in the US:

air carriers, foreign air carriers and ticket agents [must] disclose in any oral, written or electronic communication to the public, prior to the purchase of a ticket, the name of the carrier providing the service for each segment of a passenger’s itinerary

[Hartington]

I know all about the rules regarding disclosure of code sharing. I will also accept that a lot of people simply don't look at that data item and get a surprise when they don't get what they think they booked.

And that's the point. However hard the regulators and airlines try and provide the data people ignore it. All they are interested in is the price.

Why do I think it's tantarmount to fraud? If I buy a branded product then I expect the product of that brand. Ecco shoes? I don't expect Clarks shoes. If I book a BA flight number I expect to receive the BA service (even if it's M&S sandwiches). Not only service but training standards; I have a few personal rules about which airlines I'll fly on (no, there are none I simply won't fly on). If I'm sold a Delta flight number I expect to board a Delta plane, not Air France. Iworked in the industry I know to look out for code shares, it's not that I won't book them but I want to know what I'm really buying and the current system doesn't provide that information. We need to book the airline that actually operates the flight and for airlines to stop hiding behind codeshares.

[nonsense]

https://en.wikipedia.org/wiki/List_of_badge-engineered_vehicles

I suppose you think the name on the back of your car is the company who built it too?

[Hartington]

A car is physical. Airlines are a service industry.

[crewmeal]

I find codesahre flight numbers confusing. For example it's sometimes difficult to work out who flies the BHX-AMS route as there are about 8 codeshares on the departure/arrival boards. Same for the CDG route with 11 codeshares. Also the Birmingham airport website has these flights dotted all over the place.


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[DaveReidUK]

I find codesahre flight numbers confusing. For example it's sometimes difficult to work out who flies the BHX-AMS route as there are about 8 codeshares on the departure/arrival boards. Same for the CDG route with 11 codeshares.


Of the flight-tracking websites, Planefinder does a reasonable job of identifying codeshares.

If you search for a flight number, and it turns out to be a codeshare, PF will tell you the flight number of the operating flight: https://planefinder.net/data/flight/MK9338

Conversely, if the flight number you search for is an operating flight, PF tells you any codeshare flight number(s) allocated to it: https://planefinder.net/data/flight/AF1164

[Ken Borough]

However hard the regulators and airlines try and provide the data people ignore it

Therein is the problem: consumer laziness. Code-shares are not tantamount to fraud as there is plenty of disclosure during the booking process and again on the contract (ticket). There is not the slightest intention on the part of carriers to be deceptive. Next!