4-4 U.S. Airport Delays by Cause: 2012 (Table)
percent of delayed time
Cause | Delayed minutes | Percent |
---|---|---|
Aircraft arriving late | 23,569,552 | 41 |
Air carrier delay | 18,165,456 | 32 |
NAS delay | 12,828,822 | 23 |
Extreme weathera | 2,279,810 | 4 |
Security delay | 73,052 | <0.5 |
Total | 56,916,692 |
aIncludes weather events that prevent flying. Other weather delays that slow operations are included under other categories.
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, Research and Innovative Technology Administration, Bureau of Transportation Statistics, Office of Airline Information, available at www.bts.gov as of October 2013.