Same Flight number
Thread Starter
Joined: Nov 2024
Posts: 9
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From: Hongkong
Same Flight number
If the departure of a long-haul international flight is delayed significantly, is it possible that the same flight departs the next day before it lands and there are several planes with exactly the same flight number in the sky? How do you differentiate between them?
Joined: Sep 2007
Posts: 603
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From: London
Two separate issues:
A single sector flight where the previous days flight is delayed. If you look at FR24 you will see that this happens quite often. Generally a suffix is added, 'D' 'Y', etc. ATC doesn't necessarily use the published flight number, BA domestic flights were (and may still be) something like Shuttle 1 Alpha where 1 is the route. Air Canada might add 2 to the start of a flight number in case of delays.
ATC will advise crews if similar numbers (Speedbird 93 / Speedbird 193, etc) are on the same frequency.
As an aside it is not unknown for two flights of the same number to be scheduled on the same day when the clocks change. For example a HKG -LHR flight might depart at 00:15 and 23:15 local time (Lets not worry about UTC / zulu time.) In that case one flight might might be given another such as BA27 / BA1027.
Second, there may also be flights with multiple sectors, sometimes with a change of gauge. This is far less common now but in the past was quite common. For example Pan Am might have had a 747 fly into LHR from JFK and then onto Hamburg as a 727. It was not unknown for the second sector to depart before the first had landed. I think that I a number was added to the start of the 727 sector, e.g. Clipper 4102 - though I'm not sure.
Right now in the US it is common for outbound and inbound segments of a rotation to have the same flight number. (Really confusing if you ask me.) These are generally operated by the same plane from a hub to an outstation so you would not expect there to be any issues but I dare say that a substitution has ocasionally been made and the inbound and outbound are airborne at the same time. US airlines often use 8000 / 9000 codes for positiioning and charter flights and one of those could be used.
A single sector flight where the previous days flight is delayed. If you look at FR24 you will see that this happens quite often. Generally a suffix is added, 'D' 'Y', etc. ATC doesn't necessarily use the published flight number, BA domestic flights were (and may still be) something like Shuttle 1 Alpha where 1 is the route. Air Canada might add 2 to the start of a flight number in case of delays.
ATC will advise crews if similar numbers (Speedbird 93 / Speedbird 193, etc) are on the same frequency.
As an aside it is not unknown for two flights of the same number to be scheduled on the same day when the clocks change. For example a HKG -LHR flight might depart at 00:15 and 23:15 local time (Lets not worry about UTC / zulu time.) In that case one flight might might be given another such as BA27 / BA1027.
Second, there may also be flights with multiple sectors, sometimes with a change of gauge. This is far less common now but in the past was quite common. For example Pan Am might have had a 747 fly into LHR from JFK and then onto Hamburg as a 727. It was not unknown for the second sector to depart before the first had landed. I think that I a number was added to the start of the 727 sector, e.g. Clipper 4102 - though I'm not sure.
Right now in the US it is common for outbound and inbound segments of a rotation to have the same flight number. (Really confusing if you ask me.) These are generally operated by the same plane from a hub to an outstation so you would not expect there to be any issues but I dare say that a substitution has ocasionally been made and the inbound and outbound are airborne at the same time. US airlines often use 8000 / 9000 codes for positiioning and charter flights and one of those could be used.
Joined: Nov 2003
Posts: 99
Likes: 1
From: Sydney Oz
I had the experience once of having flight 2 and flight 12 and flight 22 all operating on the same route very close together. ATC asked me to amend the flight numbers of at least 2 of them to show the a/c rego instead of number. Then, the next day had flight 2 and flight 22 - close together and same dest. Okay I thought, I will use their rego's instead. What do you reckon the chances of having ECHO BRAVO CHARLIE and ECHO CHARLIE BRAVO ? Oh yeah, it happened. Simple fix but - give me a break .
Joined: Oct 2007
Aviation Qualifications: ATPL
Posts: 1,028
Likes: 121
From: Wherever I go, there I am
I had the experience once of having flight 2 and flight 12 and flight 22 all operating on the same route very close together. ATC asked me to amend the flight numbers of at least 2 of them to show the a/c rego instead of number. Then, the next day had flight 2 and flight 22 - close together and same dest. Okay I thought, I will use their rego's instead. What do you reckon the chances of having ECHO BRAVO CHARLIE and ECHO CHARLIE BRAVO ? Oh yeah, it happened. Simple fix but - give me a break .
Fast forward to maybe two weeks ago, and I was flying behind our competitors flight on the same route. If memory serves they were late and we were early, but you had two Flight 120s going from the same departure to the same destination along the same flight path, separated by 20 miles. No CPDLC for either of us, so we each just started telling each new ATC unit that we were aware of each other, so we didn't have to have the "similar sounding callsign" conversation every 30 minutes. So I assume that since I've returned to line flying, that NavCanada project has not been brought back.
