Number, except as noted
|Air carrier delay||28,040||27,897||17,194||19,293||21,240||30,155||32,476||25,185|
|Aircraft arriving late||30,588||29,814||16,764||18,177||24,978||35,104||33,466||26,984|
|National Airspace System delay||10,114||10,588||7,757||7,499||11,598||12,685||13,491||10,533|
|Delays as a percentage of scheduled flights||13.3||13.4||8.4||8.5||11.6||14.9||15.0||U|
KEY: U = data are unavailable (i.e., not calculated).
NOTES: Air carrier delay is due to circumstances within the airline's control (e.g., maintenance or crew problems, aircraft cleaning, baggage loading, and fueling). Extreme weather is significant meteorological conditions (actual or forecast) that, in the judgment of the carrier, delays or prevents the operation of a flight (e.g., tornado, blizzard, or hurricane). National Airspace System are delays and cancellations attributable to the national aviation system that refer to a broad set of conditions (e.g., non-extreme weather conditions, airport operations, heavy traffic volume, and air traffic control). Aircraft ariving late refers to the late arrival of the previous flight where the same aircraft is used for the present flight, causing the present flight to depart late. A security delay is a delay or cancellation caused by evacuation of a terminal or concourse, re-boarding of the aircraft because of a security breach, inoperative screening equipment, and/or long lines in excess of 29 minutes at screening areas.
The airlines required to report in 2003 were: Alaska Airlines, America West Airlines, American Airlines, American Eagle Airlines, ATA Airline (formerly doing business as American Trans Air), Atlantic Coast Airlines, Atlantic Southeast Airlines, Continental Airlines, Continental Express, Delta Airlines, ExpressJet Airlines, Northwest Airlines, Southwest Airlines, SkyWest Airlines, United Airlines, and US Airways. JetBlue Airways and Hawaiian Airlines reported voluntarily.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, "Causes of Flight Delays," available at http://www.bts.gov/oai, as of March 2004.