The number of flights not departing or arriving on time, cancellations, and diversions are measures of service quality.
These indicators are strongly seasonal and are affected by weather and heavy demand in winter and summer months, respectively.
|Number of scheduled flights||491,202||404,898|
|Scheduled flights percent change from same month previous year||2.70||-17.57|
|Percent of flights not arriving on time||23.77||15.08|
|Change of flights not arriving on time from same month previous year||3.83||-8.69|
|Percent of flights not departing on time||19.70||14.61|
|Change of flight not departing on time from same month previous year||3.24||-5.10|
|Percent of cancelled flights*||2.13||1.05|
|Change of cancelled flights from same month previous year||0.09||-1.08|
|Percent of diverted flights**||0.19||0.17|
|Change of diverted flights from same month previous year||0.06||-0.02|
NOTES: The current value is compared to the value from the same period in the previous year to account for seasonality.
The data cover the 10 largest U.S. air carriers. A scheduled operation consists of any nonstop segment of a flight. The term late is defined as 15 minutes after the scheduled departure or arrival time. A cancelled flight is one that was not operated but was listed in a carriers 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.
Aloha Airlines began reporting in October 2000 and is included here starting in October 2001. For comparability, the year ago changes and growth rates are based on data that excludes Aloha. American Eagle began reporting in January 2001, will be excluded here until one year's data is available to retain comparability with previous years.
The dramatic changes in the September 2001 data reflect the impact of the terrorist attacks on September 11, 2001, on aviation, including several days in which commercial air operations were suspended.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, Airline Service Quality Performance data.