FlyerIntel Research
The Same Airport, Different Airlines
Airport reliability tables treat a field as one thing. Ask which carrier you are flying and the picture changes completely.
Published August 30, 2026 · Source period July 2023 – July 2026
Summary
At ATL (Atlanta), Endeavor Air departs on time 87.0% of the time while Frontier Airlines manages 63.4%, a gap of 23.6 percentage points at the same runways, in the same weather, under the same air traffic control. Across 40 airports where at least three carriers fly enough to compare, the average gap between the best and worst performer is 10.1 points. An airport's reliability score describes the field; it does not describe your flight.
Key findings
- ATL shows the widest spread: 87.0% for Endeavor Air against 63.4% for Frontier Airlines.
- SNA (Santa Ana) is the most uniform, with only 2.3 points between its best and worst carrier.
- The average best-to-worst gap across 40 comparable airports is 10.1 percentage points.
- Which airline you fly is frequently worth more than which of a city's airports you fly from.
Why carriers diverge on the same tarmac
Weather, runway capacity and air traffic control apply equally to everyone at an airport, so the differences come from what each airline chooses. How much slack is built into the schedule between one leg and the next. Whether the airport is a hub where the carrier holds spare aircraft and crew, or an outstation where a single problem has no local remedy. How long the airline allows for turning a plane around, and whether it flies its own aircraft or a regional partner’s on the route. None of that is visible when you book, and all of it shows up in the arrival time.
Where the choice of airline matters most
| Airport | City | Best carrier | On time | Worst carrier | On time | Spread |
|---|---|---|---|---|---|---|
| ATL | Atlanta | 9E Endeavor Air | 87.0% | F9 Frontier Airlines | 63.4% | 23.6 pts |
| SFO | San Francisco | UA United Airlines | 81.8% | WN Southwest Airlines | 65.3% | 16.5 pts |
| PHL | Philadelphia | YX Republic Airways | 84.1% | F9 Frontier Airlines | 69.0% | 15.1 pts |
| HNL | Honolulu | WN Southwest Airlines | 91.4% | AS Alaska Airlines | 77.2% | 14.2 pts |
| CLE | Cleveland | UA United Airlines | 86.3% | F9 Frontier Airlines | 72.3% | 14.0 pts |
| DFW | Dallas–Fort Worth | DL Delta Air Lines | 81.9% | AA American Airlines | 68.1% | 13.8 pts |
| JFK | New York | 9E Endeavor Air | 83.6% | B6 JetBlue | 70.4% | 13.2 pts |
| FLL | Fort Lauderdale | UA United Airlines | 81.9% | NK Spirit Airlines | 68.8% | 13.1 pts |
| CLT | Charlotte | DL Delta Air Lines | 85.7% | AA American Airlines | 73.1% | 12.6 pts |
| LGA | New York | 9E Endeavor Air | 84.2% | B6 JetBlue | 72.1% | 12.2 pts |
| DEN | Denver | DL Delta Air Lines | 82.9% | WN Southwest Airlines | 71.2% | 11.7 pts |
| EWR | Newark | YX Republic Airways | 84.7% | B6 JetBlue | 73.1% | 11.7 pts |
| BNA | Nashville | DL Delta Air Lines | 86.6% | AA American Airlines | 75.0% | 11.6 pts |
| SEA | Seattle | OO SkyWest Airlines | 84.6% | WN Southwest Airlines | 73.5% | 11.1 pts |
| SLC | Salt Lake City | OO SkyWest Airlines | 89.9% | WN Southwest Airlines | 78.9% | 11.0 pts |
| SAN | San Diego | DL Delta Air Lines | 85.6% | WN Southwest Airlines | 75.3% | 10.3 pts |
| STL | St. Louis | DL Delta Air Lines | 88.3% | WN Southwest Airlines | 78.1% | 10.2 pts |
| PHX | Phoenix | DL Delta Air Lines | 87.7% | WN Southwest Airlines | 77.5% | 10.2 pts |
| BWI | Baltimore | DL Delta Air Lines | 85.1% | WN Southwest Airlines | 74.9% | 10.1 pts |
| ORD | Chicago | YX Republic Airways | 81.0% | AA American Airlines | 70.9% | 10.1 pts |
| DCA | Washington | YX Republic Airways | 81.4% | OH PSA Airlines | 71.5% | 9.9 pts |
| MIA | Miami | MQ Envoy Air | 80.7% | AA American Airlines | 71.0% | 9.7 pts |
| PDX | Portland | DL Delta Air Lines | 90.2% | WN Southwest Airlines | 80.7% | 9.5 pts |
| DTW | Detroit | 9E Endeavor Air | 86.8% | OO SkyWest Airlines | 77.4% | 9.5 pts |
| MCI | Kansas City | DL Delta Air Lines | 87.4% | AA American Airlines | 78.0% | 9.4 pts |
Airports where at least three carriers each operated 15,000 or more departures.
Reading this fairly
A carrier at the bottom of one airport’s list is not therefore a bad airline. Fleet mix matters: a regional operator flying small aircraft into a congested hub is first in the queue to be held when capacity tightens, which is a consequence of the flying it has been given rather than of how it is run. Route mix matters too, since long thin routes and short shuttle hops fail in different ways. The useful reading is narrow and practical: at this airport, over three years, these carriers departed on time at these rates.
Pages for what this report covers
Airports: Atlanta (ATL) · Santa Ana (SNA) · San Francisco (SFO) · Philadelphia (PHL) · Honolulu (HNL) · Cleveland (CLE) · Dallas–Fort Worth (DFW) · New York (JFK) · Fort Lauderdale (FLL) · Charlotte (CLT)
Airlines: Frontier Airlines · Endeavor Air · United Airlines · Southwest Airlines · Republic Airways · Alaska Airlines
Methodology
Calculated by FlyerIntel from 21,708,321 individual flight records in the US Department of Transportation Bureau of Transportation Statistics Reporting Carrier On-Time Performance dataset, covering July 2023 through July 2026. Following BTS methodology, a flight counts as delayed when it arrives 15 or more minutes after its scheduled arrival time. Cancelled and diverted flights have no arrival time and are excluded from on-time rates rather than counted as late; cancellation rates are reported separately. Full definitions are published at /methodology/. Departures only, grouped by operating carrier as the DOT records them, so flights sold under a mainline brand but flown by a regional carrier are counted against the regional. A carrier is listed at an airport only where it operated at least 15,000 departures there over the period, and an airport is listed only where at least three carriers clear that bar, so no "spread" is a comparison between two lonely operators.
Limitations
The source dataset covers scheduled domestic flights operated by carriers above the DOT reporting threshold; smaller carriers and international flights are not included. Flights sold under a mainline brand but flown by a regional carrier are attributed to the operating carrier, which is how the DOT records them. Past performance describes what has happened and is not a prediction about any individual flight. Carriers at the same airport do not fly the same mix of routes, aircraft sizes or times of day, and those differences explain part of every gap shown here. This report measures what happened; it does not isolate why.
Sources
- FlyerIntel analysis — FlyerIntel · source
- Reporting Carrier On-Time Performance — US Department of Transportation, Bureau of Transportation Statistics · source
Full FlyerIntel methodology · Report a problem with this analysis