Originally Posted by
Peter47
Wouldn't you add a suffix to distinguish them, e.g. USA740A, or something more sophisticated. Certainly thats what happened with Pan Am's intra European sectors in the 80s.
If a fleet is delayed to the following day a Z is usually added e.g. USA740Z.
However looking ar Flightradar24 what I presume are transponder codes are often different to reported airline codes e.g. BAW24R for a flight from ORD to LHR.
Transponder codes have nothing to do with flight numbers.