FlyerIntel Research
Regional and Mainline Delay Causes
69.3% of regional delay minutes are carrier or late-aircraft delay, against 75.3% for mainline carriers.
Published October 18, 2026 · Source period July 2023 – July 2026
Summary
69.3% of regional carriers’ delay minutes were carrier or late-aircraft delay, against 75.3% at mainline carriers. Weather was 11.4% of regional delay minutes and 4.4% of mainline ones.
Key findings
- Carrier and late-aircraft delay: 69.3% of regional delay minutes, 75.3% of mainline.
- The largest difference between the two kinds is late aircraft, 10.2 points apart.
- Per completed flight, regional carriers carried 15.5 reported delay minutes and mainline carriers 15.4.
- Regional and mainline carriers overlap on the carrier and late-aircraft share.
The two kinds of airline
5 regional carriers and 10 mainline carriers reported delay minutes. Of every reported delay minute at mainline carriers, 75.3% was carrier delay or late-aircraft delay, against 69.3% at regional carriers, a gap of 6.0 points. The cause that differs most between the two is late aircraft, 32.3% of regional delay minutes and 42.4% of mainline ones.
Where the delay minutes come from
| Cause | Regional carriers | Mainline carriers | Points between them |
|---|---|---|---|
| Carrier | 37.1% | 32.9% | +4.2 |
| Weather | 11.4% | 4.4% | +7.1 |
| Air traffic system | 19.1% | 20.1% | -1.0 |
| Security | 0.1% | 0.2% | 0.0 |
| Late aircraft | 32.3% | 42.4% | -10.2 |
| Carrier and late aircraft together | 69.3% | 75.3% | -6.0 |
Each figure is that cause’s share of the delay minutes the DOT assigned to the five causes together, with the minutes of every airline of the kind added up before dividing. The last row adds the carrier and late-aircraft rows.
Delay minutes per completed flight
| Cause | Regional carriers | Mainline carriers |
|---|---|---|
| Carrier | 5.8 | 5.1 |
| Weather | 1.8 | 0.7 |
| Air traffic system | 3.0 | 3.1 |
| Security | 0.0 | 0.0 |
| Late aircraft | 5.0 | 6.5 |
| All five causes | 15.5 | 15.4 |
Cause minutes of the airlines of a kind added up, over the completed flights of the same airlines. Flights that arrived on time or under 15 minutes late carry no cause minutes, so this is the delay an average flight brings with it, not the delay of a late one.
Every airline
| Airline | Kind | Scheduled flights | Carrier | Weather | Air traffic system | Security | Late aircraft | Carrier and late aircraft |
|---|---|---|---|---|---|---|---|---|
| Hawaiian Airlines | Mainline | 199,679 | 61.0% | 2.8% | 2.2% | 0.5% | 33.6% | 94.6% |
| American Airlines | Mainline | 3,019,376 | 33.4% | 5.5% | 13.7% | 0.2% | 47.3% | 80.7% |
| Frontier Airlines | Mainline | 629,235 | 27.2% | 2.5% | 18.0% | 0.0% | 52.3% | 79.5% |
| Southwest Airlines | Mainline | 4,371,639 | 27.8% | 2.6% | 18.0% | 0.3% | 51.4% | 79.2% |
| PSA Airlines | Regional | 717,562 | 29.1% | 8.3% | 13.3% | 0.2% | 49.2% | 78.2% |
| JetBlue | Mainline | 745,492 | 34.2% | 2.5% | 22.0% | 0.2% | 41.0% | 75.3% |
| Delta Air Lines | Mainline | 3,146,502 | 45.6% | 4.7% | 20.0% | 0.1% | 29.7% | 75.2% |
| Allegiant Air | Mainline | 381,495 | 32.1% | 10.9% | 18.1% | 0.3% | 38.6% | 70.7% |
| Endeavor Air | Regional | 304,230 | 31.9% | 7.2% | 22.5% | <0.1% | 38.4% | 70.2% |
| SkyWest Airlines | Regional | 2,433,643 | 48.7% | 14.4% | 15.9% | 0.1% | 20.9% | 69.6% |
| Alaska Airlines | Mainline | 813,732 | 30.4% | 4.1% | 26.0% | 0.5% | 39.0% | 69.5% |
| United Airlines | Mainline | 2,418,979 | 27.9% | 5.1% | 28.7% | <0.1% | 38.4% | 66.3% |
| Envoy Air | Regional | 886,878 | 21.9% | 11.7% | 22.2% | 0.1% | 44.1% | 66.0% |
| Republic Airways | Regional | 1,004,281 | 24.8% | 6.6% | 32.9% | 0.1% | 35.7% | 60.4% |
| Spirit Airlines | Mainline | 635,598 | 27.3% | 2.9% | 41.1% | 0.5% | 28.2% | 55.5% |
Airlines ordered by the share of their delay minutes that are carrier or late-aircraft delay. Each share is of the five causes together.
Does the kind of airline settle it
The two kinds overlap. Among regional carriers the share runs from 60.4% at Republic Airways to 78.2% at PSA Airlines, and among mainline carriers from 55.5% at Spirit Airlines to 94.6% at Hawaiian Airlines, so knowing that an airline is regional or mainline does not say which side of the other kind it falls on. Weather is 11.4% of regional delay minutes and 4.4% of mainline ones, and late aircraft 32.3% and 42.4%.
What this does not show
The DOT assigns each delayed arrival to a cause from the airline’s own report, and late aircraft means the aircraft arrived late from its previous flight, a delay that may have begun in weather or traffic control.So carrier and late-aircraft delay is the part not assigned to weather, the air traffic system or security. It is not a measure of what an airline could have prevented. Regional carriers fly different routes and from different airports than mainline carriers do, and the data here does not hold route or airport fixed. The report on regional carriers and mainline brands covers cancellations and on-time rates.
Pages for what this report covers
Airlines: Hawaiian Airlines · American Airlines · Frontier Airlines · Southwest Airlines · PSA Airlines · JetBlue
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/. Delay minutes are the DOT’s cause minutes, which exist only for flights that arrived 15 or more minutes late, summed over each airline across every airport and year. A regional carrier is one listed in FlyerIntel’s airline registry as flying for a mainline brand; a mainline carrier is a covered airline that is not. Airlines need 10,000 scheduled flights to be included. Shares have the sum of the five cause columns of the same rows as their denominator.
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. Cause attribution is reported by the airlines themselves.
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