|Total operations||5,202,096||5,041,200||5,270,893||5,076,925||5,092,157||5,070,501||5,180,048||5,327,435||5,351,983||5,411,843||5,384,721||5,527,884||5,683,047||5,967,780||5,271,359||(R) 6,488,540||7,129,270|
|Late departuresa||730,712||883,167||753,182||621,509||617,148||661,056||729,960||827,934||973,948||846,870||870,395||937,273||1,131,663||953,808||717,368||(R) 834,390||1,187,619|
|Late arrivalsb||1,042,452||1,208,470||1,087,774||890,068||902,567||931,437||960,254||1,039,250||1,220,045||1,083,834||1,070,071||1,152,725||1,356,040||1,104,439||868,225||(R) 1,057,804||1,421,406|
KEY: R = revised.
a Prior to 1995, late departures comprises flights departing 15 minutes or more after the scheduled time and flights cancelled. Beginning in 1995, late departures is only flights departing 15 minutes or more after the scheduled departure time.
b Prior to 1995, late arrivals comprises flights arriving 15 minutes or more after the scheduled arrival time, flights cancelled, and flights diverted. Beginning in 1995, late arrivals is only flights arriving 15 minutes or more after the scheduled arrival time.
Late departures and arrivals are strongly seasonal and are affected by weather and heavy demand in winter and summer months. The term "late" is defined as 15 minutes after the scheduled departure or arrival time. A canceled flight is one that was not operated, but was listed in a carrier's computer reservation system within seven calendar days of the scheduled departure. A diverted flight is one that left from the scheduled departure airport but flew to a destination point other than the scheduled destination point. In 2004, 19 air carriers reported on-time performance data, including all major U.S. carriers (carriers with at least one percent of total domestic scheduled-service passenger revenues) and other carriers that reported voluntarily. The number of carriers reporting in previous years is as follows: 2003 (18); 2002 (10); 2001 (12); 2000 (11); 1999 (10); 1998 (10); 1997 (10); 1996 (10); and 1995 (10).
1988-94: U.S. Department of Transportation, Bureau of Transportation Statistics, Office of Airline Information, Airline Service Quality Performance data.
1995-2004: Ibid., Summary of Airline On-Time Performance Year-to-date through December 2004 (Washington, DC: 2005), Internet site www.bts.gov/programs/airline_information/annual_airline_on_time_performance as of Feb. 25, 2005.