4-4 U.S. Airport Delays by Cause: 2014
Thursday, December 24, 2015
percent of delayed time
| Cause | Delayed minutes | Percent |
|---|---|---|
| Security delay | 65,350 | <0.5 |
| Extreme weathera | 2,988,669 | 4 |
| NAS delay | 16,519,549 | 23 |
| Air carrier delay | 21,259,409 | 30 |
| Aircraft arriving lateb | 29,483,984 | 42 |
| Total | 70,316,961 |
aIncludes weather events that prevent flying. Other weather delays that slow operations are included under other categories. bDelay resulting from a previous flight with the same aircraft arriving late.
Key: NAS = Delays attributable to the national aviation system (NAS) that refer to a broad set of conditions, such as non-extreme weather, airport operations, heavy traffic volume, and air traffic control.
Note: Percents do not add to 100 due to rounding.
Source: U.S. Department of Transportation, Bureau of Transportation Statistics, Office of Airline Information, available at www.bts.gov as of September 2015.