Pity the passengers on AirTran Flight 576, which is supposed to leave Atlanta every afternoon at 4:54 p.m. and arrive at Newark Airport in New Jersey at 7:07 p.m. When it actually gets there, however, is almost anyone's guess.
That is because Flight 576 has the dubious distinction of being late more often - 72 percent of the time - than any other flight in the United States during the past 12 months, according to government data.
As dismal as that might sound, some travelers have had it even worse this year. Six flights from airlines such as United, Delta, Independence Air and AirTran were delayed 100 percent of the time for a full month this year.
The Transportation Department defines a delayed flight as one that departed or arrived at least 15 minutes late.
This is not a good time for time-conscious air travelers. Data from the Transportation Department's Bureau of Transportation Statistics last week showed that this was shaping up to be the worst year for departure delays since 2000. For the year through June, nearly one in five flights, or 17 percent, left airports late.
To placate exasperated passengers, airlines have scrambled to get their planes in on time - by flying faster once in the air, for example, which burns more fuel. This actually led to a slight improvement in on-time arrivals this year compared with last year: 78 percent versus 77.8 percent. But at certain times of the day, like late afternoon and evening, and at some airports, like Atlanta Hartsfield, Newark Liberty International and Chicago O'Hare, delays are almost a given, and airline timetables bear little semblance to reality.
Chris McGinnis, editor of a travel newsletter called The Ticket, said that the airlines, which have collectively lost $30 billion since 2000 and stand to lose at least another $5 billion this year, are trying to get as many jets into the sky as possible each day in the slim hope of making a little money on each one.
The airlines say they would like to do better, and several, including Delta, United and American, have made attempts to improve their performance at the most delay-prone airports.
Fundamentally, however, they contend that they are hampered by the nation's overstretched air traffic control system, by weather and by the need to offer enough flights to compete with other airlines.
And unless told by the government to cut back, as has happened to American and United at Chicago O'Hare, they simply keep flying.
But Christopher J. Mayer, a professor at Columbia University's Graduate School of Business, says airlines can do more. In two studies of airlines' schedules over the past 12 years, Mayer concluded that airlines rarely make adjustments in their timetables, even when they can easily predict when there will be bad weather or heavy traffic, rendering their schedules unrealistic.
"The perception people have that they are abused by the airlines is actually right," Mayer said.
Delta is trying its best to get two of its flights off the most-delayed list. It has already retooled one problem performer, Flight 5803, between Washington Dulles and Cincinnati.
Until June, the flight stopped in Atlanta on the way, only to be hung up frequently by weather delays. Now the flight, operated by Delta's Comair subsidiary, travels directly between Dulles and Cincinnati. While it remains on the worst-performing list, its on-time record has improved, said Chris E. Kelly, a Delta spokeswoman.
Mayer said that airlines have all the tools they need to fix their flight delays. He sees a more important factor at play: cheap fares. With passengers intent on paying as little as they can for tickets, airlines do not think they can successfully market timeliness, he said. So most simply let the issue slide.
Passengers "are not going to change their behavior," Mayer said - in other words, if they are not willing to spend more money to arrive on time, neither will the airlines.