|On-time flight operations (percent)||79.4%||82.5%||82.3%||81.6%||81.5%||78.6%||74.5%||77.7%||77.2%||76.1%||72.6%||77.4%|
a Data include nonstop scheduled service between points within the United States (including territories) by the 10 largest U.S. air carriers (i.e., those with at least 1% of the total domestic scheduled service passenger revenues: Alaska, America West, American, Continental, Delta, Northwest, Southwest, TWA, United, and US Airways).
A flight is considered on time if it arrived less than 15 minutes after the scheduled time shown in the carriers' Computerized Reservations Systems. Canceled and diverted operations are counted as late.
U.S. Department of Transportation, Office of the Secretary, Air Travel Consumer Report (Washington, DC: Annual February compilations), table 1a, 12-month column.