Summary: Pursuant to a congressional request, GAO assessed whether: (1) airlines increased scheduled flight time to keep reported delays at a minimum in response to the Department of Transportation's (DOT) on-time performance reporting requirement; and (2) DOT verifies that flights omitted from reported data because of mechanical problems had in fact experienced mechanical problems.
GAO found that: (1) DOT investigated airline scheduling practices during 1986 and 1987 and instituted the on-time reporting requirement; (2) to improve on-time performance, airlines adjusted scheduled flight time and streamlined flight operations; (3) airlines were allowed to exclude flights experiencing mechanical problems from the on-time data, to ensure that they did not operate unsafe planes; and (4) weather and air traffic control system problems were the principal reasons for late flights. GAO also found that: (1) the DOT reporting system measured whether flights departed and arrived within 15 minutes of their scheduled times, but did not include actual flight times; (2) on-time statistics did not provide information on changes that airlines made to scheduled flight times to facilitate on-time performance; and (3) DOT did not routinely verify whether flight delays were actually caused by mechanical problems.
