4-4 U.S. Airport Delays by Cause: 2013
Monday, December 29, 2014
percent of delayed time
| Cause | Delayed minutes | Percent |
|---|---|---|
| Security delay | 103,651 | <0.5 |
| Extreme weathera | 2,974,153 | 4 |
| NAS delay | 17,426,866 | 24 |
| Air carrier delay | 21,136,897 | 29 |
| Aircraft arriving lateb | 30,296,035 | 42 |
| Total | 71,937,602 |
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 2014.