1P

Two Fedex flights, both numbered 522, materialized today about 30 miles apart on their way from Cologne to Memphis. One of them was running exactly 24 hours late.

Needless to say, it caused a lot of confusion among the controllers, not to mention danger. Eventually they worked out what the problem was and renumbered one of the flights.

Anyone know if this sort of thing has happened before?

milepig

Happens more than you think, usually when a flight gets off schedule (like the above situation). An example of something that might be more typical would be when a flight from, let's say SFO-ORD-LHR (with a plane change at ORD) gets behind on the SFO-ORD leg, and the ORD-LHR (with the same flight number) takes off before the SFO-ORD lands. I don't know what every airline does, but UA tacks a 9 onto the front of the second flight - so in the example I use SFO-ORD would be xxx and ORD-LHR sould be 9xxx.

Gamecock

Never thought about something like this, but it makes sense...

icarusKiD

I had a suspicion about this a few months ago. I was headed from DEN to MSP on DL and it was arriving a hour late. There was a large tour group connecting to CDG (AF codeshare I think). The MSP - CDG flight was the same flight number. They made a heroic announcement they were "holding the plane" for that group and they should deplane first. I figured they actually couldn't leave the gate until the flight sharing the same number landed. Maybe I'm just a cynic...

B747-437B

Yes, but usually Eurocontrol's CFMU will kick the flight plan back for the second one filed on the grounds that it is a duplicate flight number. This is usually fixed by adding on an extra alphanumeric character to the original flight number (eg. 522A, or 9522).

Standard practice is that airlines will not have the same flight number departing anytime during the same calendar day (measured in UTC / Zulu). This is what CFMU checks for when accepting a flight plan. It is only when the departure times are closely spaced but on either side of midnight Zulu that the computers may accept it and create a situation where both flights are in the same FIR simultaneously.

Also, just as an aside, the OPERATIONAL flight number (used for flight planning purposes) and the COMMERCIAL flight number (seen by the consumers) may or may not be the same. Many airlines use randomly generated operational flight numbers rather than the commercial flight number to avoid conflicts like this. So what a passenger knows as flight BA 123 may actually have an operational flight number like BAW 3X7G.

Wally Bird

Well I couldn't find a FedEx flight 522, but there were two flight 5225 that day:(www.libhomeradar.org)

Ocn Vw 1K

As noted, this has been an issue for some carriers for the last few years, as different segments of the same airline's flight number are assigned to different aircraft; and, due to delays, two aircraft using the same flight number, may be in the same en route center's (or tower's or TRACON's) airspace at the same time.

For example, United 262 may be a SFO->DEN flight; and United 262 may also be operated by a different airplane, DEN->PHL. If the first segment is late into DEN and the airline doesn't hold the second segment, there'll be a number conflict. The solution for some carriers at least in domestic airspace, is to add a letter after the flight number, so for example, 262Q and 262T, keeps them apart in the ATC computers.

ironmanjt

This actually happened to me years ago on my first every UA flight with Channel 9 turned on. The captain explained we would be United 925-Kilo in order to avoid confusion with another 925 which was going under 925-Quebec that day.

flyinbob

I thought things like COMPUTERS were supposed to sort that kind of thing out. Don't airlines file flight plans with flight numbers? Isn't there something in place to prevent 2 of the same flight numbers in the system at the same time? Seems like it would be a simple fix.

frambusch

Actually, they refer to this as a "Stubbed Flight". Delta adds a 9 to the front of the flight number of the second flight. Other airlines have different numbering conventions. I have actually seen the words "Stubbed Flight" on the gate display. I have no idea where the expression "Stubbed" comes from. Does anyone know?

fti

Unfortunately airlines often don't hold the connecting flight in case of delays of the first flight under that flight number. That is the fallacy of "direct flights" with one flight number but a "change of gauge." Pretty deceptive if you ask me, but the US government allows it.

:D!

When some years ago, my CX flight was delayed by nearly 24h, it was renumbered CX000D. (forgot the number)

B747-437B

My worst situation, after a multiple day compound delay, was flights tagged as A, B, C, P and T in addition to the original flight. Sometimes it really hits the fan.

buckeyefanflyer

Usually when this happens they renumber the delayed flight, that;s what CO and UA always did. Not good, someone was not thinking.

Calchas

Similar situation!

http://airlinepilotchatter.blogspot....same-call.html