Originally Posted by
pgppetch
When a flight number is changed and the time is changed a bit it seems to become a "new flight" for the purpose of reported on time statistics. Creating a new flight this way allows wiping out any poorly performing flight and gives time for the new flight number to establish its "new" on time record.
That's just flat out wrong. If it were true, then 75% of the flights would be "new".
DOT tracks flights as being (for example) the 5pm-ish DFW-LGA.
It could be #123 departing at 5:01 one week and #989 at 5:05 the next week, those are the same flight for DOT on time rankings.
Per 14 CFR Part 234 (Airline Service Quality Performance Reports), Part 234.2 (Definitions):
New flight means a flight added to a carrier's schedule to operate in a specific origin-destination city pair and not scheduled to depart within 30 minutes of any discontinued flight that was contained in the carrier's published schedules for the same city pair during the previous month.
I was a Gate AAgent 30+ years ago, long before DOT on-time reporting. AA has always had this habit of tweaking flight numbers, departure times, pairings etc.