Callsigns
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Callsigns
Quick question.
How are callsigns determined?
For example in an airport the flights will have a particular code e.g. BA906, AA30 etc, but at ATCC's the callsigns are different e.g. BA906 might be BAW16MP or AA30 could be AAL6. Just wondering whether these callsigns are random or whether they are allocated depending on things such as destination perhaps...
Thanks,
Kirk
How are callsigns determined?
For example in an airport the flights will have a particular code e.g. BA906, AA30 etc, but at ATCC's the callsigns are different e.g. BA906 might be BAW16MP or AA30 could be AAL6. Just wondering whether these callsigns are random or whether they are allocated depending on things such as destination perhaps...
Thanks,
Kirk
Joined: Dec 1999
Posts: 4,432
Likes: 33
From: LHR/EGLL
It's usually from the flight number, as you've seen, but sometimes that conflicts with others.. (at LHR, BAW55, BAW155 and BAW115 used to depart within a few minutes of each other....)..and might cause confusion. That's why some are altered to alpha-numeric.
Other airlines have different systems. Midland have BMAxHY LHR-EDI, and BMAxEH EDI-LHR.
Other airlines have different systems. Midland have BMAxHY LHR-EDI, and BMAxEH EDI-LHR.
Joined: Oct 2000
Posts: 8,266
Likes: 1
From: Berkshire, UK
Kirk... you are not correct in saying that callsigns vary from airport to ATCC. In fact they remain exactly the same throughout the flight from take-off to touchdown. You're confusing the flight numbers and the radio callsigns, which are two different things, and may differ as Gonzo has explained.
The callsigns and flight numbers will be the same for a particular flight every day but ATC can request a pilot to use a different callsign if confusion exists with another aircraft. One way is to get one aircraft to use its registration number, but this doesn't happen often.
The callsigns and flight numbers will be the same for a particular flight every day but ATC can request a pilot to use a different callsign if confusion exists with another aircraft. One way is to get one aircraft to use its registration number, but this doesn't happen often.
Joined: May 2000
Posts: 383
Likes: 0
From: London
The original callsigns are not always numbers only. Already covering what has been said above, it is the airline filing the flight plan that will decide the callsign, a lot use the flight number that the passengers would see, others will have an alpha numeric callsign that is completly different to the flight number.
They normally follow a pattern if they are alpha numeric in that flights from A-B will have a set of callsigns for that route and flights from A-D will have another set.
They normally follow a pattern if they are alpha numeric in that flights from A-B will have a set of callsigns for that route and flights from A-D will have another set.
Joined: Oct 2000
Posts: 8,266
Likes: 1
From: Berkshire, UK
No, the airlines decide the callsigns. Some will be exactly the same as the flight number and others may vary if the airline is attempting to reduce confusion. Callsign confusion is a very serious problem and many airlines have experimented with different callsigns, usually a combination of letters and numbers. Sometimes it works, sometimes it doesn't! Even callsigns which are actual flight numbers may have letters added for the benefit of the airline. Eg is a flight is delayed from yesterday it may have the same number with a letter added at the end.
The callsign and fligh number for a particular scheduled flight will be the same every day. The callsign may change if dangerous confusion arises.
The callsign and fligh number for a particular scheduled flight will be the same every day. The callsign may change if dangerous confusion arises.
Joined: Jul 2004
Posts: 152
Likes: 0
From: Here, there and everywhere
And to prove Heathrow Director's statement, following an MOR a few months ago (I think by one of the London sectors), the BMI Baby from Paris to Durham Tees Valley has been "renamed" BMI56K, however the outbound causes no confusion and remains the same as the passenger flight number (which I cannot remember right now - BMI4977?)
Of course the potential "danger" still exists if BA decide to have BAW14AL and Midland decide to have BMI14AL...then you're back to square one :-)
-HD-
Of course the potential "danger" still exists if BA decide to have BAW14AL and Midland decide to have BMI14AL...then you're back to square one :-)
-HD-
Joined: Dec 2001
Posts: 121
Likes: 0
From: UK
Hi Kirk.As has already been said,the airlines choose the callsign. Alphanumeric ones tend to stop similar callsigns by the same company however if diffirent companies use the same letters at the end of the callsign then the problem remains. BMA and BRT have callsigns that end in CW that arrive at the same time in the scottish tma. ATC can also request a change of callsign for a portion or for all of the flight for callsigns sounding similar or looking similar on radar eg SHT6E SHT6F
cheers,rolaaand
cheers,rolaaand
Joined: Oct 2000
Posts: 8,266
Likes: 1
From: Berkshire, UK
Some may recall the round-the-world PanAm flights many years ago, all using one callsign (Clipper 1? I can't recall exactly). At Heathrow we several times had two aircraft active using same callsign!
The only sensible system would be to revert to using aircraft registrations, which are unique and was the norm 40+ years ago, but the stored flightplan system would have to be changed somewhat I guess.
The only sensible system would be to revert to using aircraft registrations, which are unique and was the norm 40+ years ago, but the stored flightplan system would have to be changed somewhat I guess.
Joined: Mar 2001
Posts: 489
Likes: 0
From: Asgard
That happened to me a few times, though not at EGLL, but at a Scottish airfield....the operator being Air Ecosse. Disturbing when one has just cleared an aircraft to land to get a call from the same callsign asking for start up.
