Why do some flights have more than one fa_ident?


The graph shows the sum of distinct fa_idents per day in November for the top 100 airlines. The area marked “1” has a gap because my code was not running and I did not collect any schedule data for that period.

The area 2, however, shows that there were an unusually high number of flights scheduled (unique flights identified by unique fa_idents). I believe the problem is that one flight number got multiple fa_idents, for example DLH118 on Nov 8 or 9.

Is there a good reason this happens? And if it does happen, should I be using ident in combination with date rather than fa_ident to identify unique flights?


Our system may allocate a new faFlightID when we detect positions for an aircraft that doesn’t seem to match any of the flightplans that we already have received. In some cases, it may be a legitimately unscheduled flight, but sometimes it is just a misclassification that should have been associated with an existing flightplan.

As mentioned in a prior thread by you, there can be a drop in flight tracking accuracy during the IATA season change when we lack updated data about aircraft/flight mappings.

If you can find ongoing examples of specific faFlightIDs that seem to be incorrectly matched after the IATA season change event, then we would be happy to analyze the issue that may be affecting them.