Have a unique (at least to me) situation I've run into. What happens if a flight that carries the same number as one that's enroute is ready for departure?

If you mean as far as ATC is concerned, they simply give it another number, like UA 935 might become UA 9455. As far as UA itself, I don't think it matters. They can have 2 flights with the same number operating.

They will usually add a letter to the end for ATC purposes. So the second 935 becomes "935 Bravo" or some other letter.

Right. Thanks. Makes sense. Just got worried there for a min thinking the 2nd flight wouldn't leave until the first lands. :-)

I've heard Tango, and in 2007 Tango, Juliet, and Kilo were popular: http://www.flyertalk.com/forum/unite...threads-3.html

To domer: If the first segment is late, the second segment will leave without the first one -- same situation as if they had different flight numbers.

I have seen UA sometimes hold a flight to accommodate misconnecting passengers from a late inbound, but the only thing special about the "same flight number" situation is that there may be a lot of misconnecting passengers if a lot of people bought the direct flight A-B-C on one flight number.

I had this happen to me on a Delta flight a couple of weeks ago. To the passengers, the flight still had the same number, but for the pilots and ATC, we had a new flight number in the 9000s. Since the passengers didn't know about the new flight number, quite a few struggled when trying to track our flight while enroute using the inflight Wi-Fi!

Sounds like you bought a "direct" flight only to find that you need to "change planes" (make a connection) with the possibility of misconnecting. Yes, your second segment may leave without you and leave you stranded at the intermediate airport.

in certain irrops situations, it can be quite common for the AAA - Hub leg of a flight to be cxld or severely delayed, but the Hub - BBB leg to be on-time. I saw this a few years ago when flying through ATL as a hurricane hit the east coast. Lots of inbound flights were cxld, but these were largely balanced out by cxld outbound flights to those same cities (i.e. DL still had plenty of available aircraft), hence the hub-destination flights were often undisturbed.

I haven't noticed that here in UK or in Asia, I take it this practice is common in the US. IMO, it sounds silly, if your flight from A to B happens to stop at C and the latter flt is operated with a different aircraft, it should have a different flt number for route B to C than A to C. It's only acceptable practice imo if the entire flight is operated by the same aircraft and is listed as having a stop-over.

But in the airline industry "direct flights" and "non-stop" means two different things, "direct flights" can have a stopover whilst "non-stop flight" is quite literally non-stop.

I suppose one can assume, these carriers who have these "direct flights" have decided to include 'aircraft change' alongside with its primary defination of disembarking/picking up additional pax at the stopover and/or refuelling.

Depends where the two flights are. If they are within or near the same airspace, one of them will have the flight number changed for ATC reasons. If the two flights are no where near each other, there is no need to change. You could have two flights numbered QF10, one in European airspace, another in Australian airspace.

It does happen in Europe, less in Asia as there is just not the plethora of flights to deal with. I mean a lot of Airlines in Asia don't have a need to go above 3 numbers.

A couple of years ago I was flying back to HKG from LHR on BA27. We had an engine surge on t/o and after a couple of hours enroute, the decision was made to go back to LHR. By the time we arrived back in the UK it was about 2am and we were all put up in a hotel overnight and told that we would be rescheduled for the next afternoon. So the following day, we flew out to HKG on flight BA27Y, a few hours ahead of that day's BA27.

Among airlines I know about, Cathay Pacific, Southwest, and Alaska all have it so that the same flight number means that you are scheduled to stay on the same airplane. On United and Delta, the same flight number is no guarantee that you are scheduled to stay on the same aircraft, and in most cases, you will not and have to make a connection (or miss the connection).

Over in Delta-land, this happens regularly on (for example) the continuing Atlanta-Sydney routes that stop in Los Angeles. The 777 used for DL17 between ATL-LAX is not actually the same plane that continues LAX-SYD - the transpac aircraft currently comes in from DTW.

I've heard they designate the ATL-LAX flight 17A when it is running significantly delayed to differentiate it from the (possibly on time) LAX-SYD departure... no data to back this up but I do recall it coming up in a discussion previously, and it matches with what some others have said so far in this thread.

To those being "inflicted" by UA or DL lol, do you get 2 BPs or just the one and hope the check-in agent tells ya with onboard announcement as a reminder?