The fair ranking
Which airline runs on time, once you hold constant what each one flies?
The raw ranking sorts carriers by their average arrival delay. The adjusted ranking holds constant the route, the month, the scheduled hour and the aircraft type, so a carrier that flies into the hardest airports at the busiest hours is compared with other carriers on the same routes at the same hours. Both are fit on 2023 onward, with intervals clustered by day.
The ranking changes once you hold constant what each carrier flies: PSA Airlines rises 4 places and Hawaiian Airlines falls 7
Carrier rank on mean arrival delay, raw and adjusted for route, month, hour and aircraft type
Source: BTS on time files joined to the FAA aircraft registry, model: fixed effects on weighted cells, scheduled flights 2023 to 2026-07, as of 2026-10-01.
Raw beside adjusted
| Carrier | Flights | Raw rank | Raw effect | Adjusted rank | Adjusted effect | Interval | Moved |
|---|---|---|---|---|---|---|---|
| Endeavor Air | 391,977 | 1 | -7.39 min | 1 | -13.14 min | -14.14 to -12.14 min | same |
| Republic Airways | 1,119,192 | 2 | -6.26 min | 2 | -8.70 min | -9.36 to -8.03 min | same |
| Envoy Air | 975,162 | 5 | -2.36 min | 3 | -6.10 min | -6.78 to -5.42 min | up 2 |
| Delta Air Lines | 3,572,228 | 4 | -3.63 min | 4 | -2.92 min | -3.26 to -2.58 min | same |
| United Airlines | 2,729,655 | 7 | -1.18 min | 5 | -2.55 min | -2.90 to -2.21 min | up 2 |
| SkyWest Airlines | 2,713,958 | 9 | +0.16 min | 6 | -2.38 min | -3.00 to -1.76 min | up 3 |
| PSA Airlines | 784,660 | 11 | +4.19 min | 7 | -1.58 min | -2.44 to -0.71 min | up 4 |
| Southwest Airlines | 5,003,261 | 6 | -1.63 min | 8 | +1.71 min | +1.40 to +2.02 min | down 2 |
| Alaska Airlines | 918,478 | 3 | -3.98 min | 9 | +2.78 min | +2.39 to +3.16 min | down 6 |
| Spirit Airlines | 749,263 | 10 | +3.14 min | 10 | +3.09 min | +2.52 to +3.66 min | same |
| JetBlue Airways | 866,026 | 13 | +5.99 min | 11 | +3.76 min | +3.17 to +4.35 min | up 2 |
| American Airlines | 3,411,235 | 14 | +6.18 min | 12 | +5.17 min | +4.83 to +5.50 min | up 2 |
| Allegiant Air | 435,740 | 12 | +5.56 min | 13 | +6.86 min | +5.71 to +8.01 min | down 1 |
| Frontier Airlines | 695,137 | 15 | +8.03 min | 14 | +8.54 min | +7.99 to +9.10 min | up 1 |
| Hawaiian Airlines | 236,810 | 8 | -0.66 min | 15 | +11.42 min | +10.61 to +12.24 min | down 7 |
Source: BTS on time files joined to the FAA registry (real); model: fixed_effects; population: scheduled flights 2023 to 2026-07; as of 2026-10-01.
The model
Arrival delay on carrier with route, month, departure hour and aircraft type fixed effects, weighted least squares on cells; effects relative to the flight weighted average carrier.
Plan 859c5a40bab6906c, registered before the fit. Cluster robust by day, scores summed over flights. The fit used 3,025,819 cells over 1,308 days.
Proven on the simulator first
On a simulated network where the true carrier effects are known and better carriers are steered onto harder routes, the adjusted ranking's rank correlation with the truth averaged 0.94 under strong confounding, against -0.07 for the raw ranking; with moderate confounding 0.95 against 0.14, and with none 0.97 against 0.75.
What the ops director would push back on
My carrier flies the hardest routes. This page is the answer to that objection: the route, month, hour and aircraft are held constant. What it does not hold constant is anything the carrier chooses that the data does not record, such as how many spare aircraft and crews it keeps and how tightly it schedules its turns. Those are the carrier's own decisions, and the ranking is right to charge them to the carrier. A regional carrier flying for several mainline brands is ranked as itself, because that is how it reports.