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FLIGHT DELAYS
This section provides information about airline on-time performance, flight delays, and cancellations. It is based on data filed by airlines each month with the Department of Transportation’s Bureau of
Transportation Statistics (Office of Airline Information), as described in 14 CFR Part 234 of DOT’s regulations. It covers nonstop operated and marketed scheduled-service flights between points within the
United States (including territories) by the sixteen (16) U.S. air carriers that have at least 0.5 percent of total domestic scheduled-service passenger revenues.
The reportable airports with respect to which data must be submitted to the Department are those large, medium, small, or non-hub airports as defined in 49 U.S.C. 47102. Airports can be accessed through the
FAA at: https://www.faa.gov/airports/planning_capacity/passenger_allcargo_stats/categories/. This report includes the 30 largest U.S. airports, except Table 5, which lists more than 200 airports in alphabetical
order with the corresponding on-time arrival and departure percentages.
A flight is counted as “on-time” if it operated less than 15 minutes after the scheduled time shown in the carriers’ Computerized Reservations Systems (CRS). All tables in this report except Table 4 are based on
gate arrival times; Table 4 is based on gate departure times.
In fulfilling DOT’s data reporting requirements, the reporting air carriers use automated and/or manual systems for collecting flight data. Those using an automated system rely on the Aircraft Communication
Addressing and Reporting System (ACARS) or the Docking Guidance System (DGS). Based on the latest information available to DOT, of the 16 reporting air carriers, 13 carriers (Alaska, Delta, Endeavor,
Envoy, Frontier, JetBlue, PSA, Republic, Hawaiian, SkyWest, Spirit, Southwest, and United) use ACARS, one carrier (American) uses a combination of ACARS and DGS, one carrier (Mesa) uses a combination
of ACARS and a manual system, and one carrier (Allegiant) uses a manual system.
A carrier may voluntarily file data for its entire domestic system. Tables 2, 2A, 3, and 4 are limited to the 30 largest airports; Tables 5, 6, 6A, 7 and 7A contain data on flights to/from all airports that were
reported.
Tables 1 through 4 display percentages of flight operations that were on-time. Tables 1, 1A, 1B, 2 and 2A present data by marketing or reporting carrier; airlines are ranked by performance in Tables 1/1A and
are listed in alphabetical order in Table 2/2A (see Appendix for codes). Table 1B shows marketing carrier rankings by month and Year-to-Date (YTD) on the percentage of flight operations that arrived on time.
Tables 3 and 4 contain information by airport and time of day time of day that a flight operated in 24-hour clock format. All times are local. A 10:50 departure from Atlanta is 10:50 Atlanta time; if that flight
arrived in Dallas at 23:45, that is 11:45 p.m. Dallas time. Table 5 lists all airports for which there are reports this month in alphabetical order with the corresponding on-time arrival and departure percentages.
Tables 6 and 6A display the number of operations, number of flight cancellations, and percentage of cancellations by air carrier marketing and reporting flights at all airports and for the air carriers’ domestic
system. Table 7 and 7A displays airline flight delay causation data by categories, and Table 7B provides an overall graphic representation of that data. Table 8 lists the regularly scheduled flights with tarmac
delays of more than 3 hours and Table 8A lists the regularly scheduled international flights with tarmac delays of more than 4 hours.
Except for the flights listed in Tables 8 and 8A this report provides summary information - it does not show the on-time record of individual flights. The on-time performance for individual markets and flights
can be searched at https://www.transtats.bts.gov/ONTIME/
Airline Service Quality Performance data from the most recent six months is available for free download at: https://www.bts.gov/topics/airlines-and-airports/airline-information-download. Additional summary
data for airports and airlines can be found at BTS’ Flight Delays at-a-Glance at: https://www.bts.gov/browse-statistical-products-and-data/bts-publications/airline-service-quality-performance-234-time. Cause
of delay data for airports and airlines can be found at: http://www.transtats.bts.gov/OT_Delay/OT_DelayCause1.asp.
Information on the performance of specific flights is displayed on the CRS used by most airlines and travel agencies. Each of the reporting carriers’ flights have a one-digit code between 0 and 9 representing that
flight’s percentage of on-time operations for the latest reported month. For example, “8” means that flight arrived on-time (within 15 minutes) between 80% and 89.9% of the time during the latest reported
month.