United, Delta, and American appear to have remarkable records for on-time performance, ranking right up there in the 80% range, on average. Meanwhile, JetBlue and Southwest have numbers dipping down into the 60% range. Is there really that much difference between and among airlines for on-time performance? Nope, there is not. United, Delta, and American have regional jet flights (Delta Connection, American Eagle, and United Express) that are operated by other companies. However, those regional flights are marketed as American, Delta, and United Flights. Most passengers are not even aware that there are these operating partnerships. And seasoned travelers know that the regional flights are notoriously late, canceled, and riddled with challenges. American, Delta, and United do not count those regional flights in their on-time performance data.
Until now. JetBlue and Southwest on-time performances include virtually all of their flights. American, Delta, and United include only their non-regional flights. The third-party operated but airline-marketed flights are not included in their overall on-time percentages. Not bad when you can spike the curve! However, starting in 2018, the data points change and so will the on-time performance rates. Except for the airlines that were already counting all of their flights.