Think flight times are being padded? They are

— -- The Earth hasn't expanded significantly. The seismic plates under North America haven't shifted dramatically. And quite a few commercial aircraft are faster than ever. But it's still taking longer to fly on many domestic routes — and flight times are growing longer, not shorter.

Don't believe it? Check out the chart below and see just how much scheduled flight times have been stretched since 1995. For airline executives facing chronic delays on certain routes, the answer has been to pad those flights' "block times" by lengthening the total number of minutes the aircraft is expected to operate, all the way from the gate at Airport A to the gate at Airport B.

As one airline operations manager said to me a few years ago: "The airlines are no more on-time than they used to be, but they're better at covering it up."

Back to the future

Throughout most of the history of aviation, flight times naturally decreased as navigational technology improved and airplanes grew faster. But now, at congested airports around the nation, the technological sweet spot is long past. That's not because airplanes have gotten slower; in fact, Boeing says its new 787 Dreamliner will cruise at Mach 0.85, similar to the fastest wide-bodies. Rather it's because the situation is akin to a Ferrari F430 stalled in bumper-to-bumper traffic on a clogged interstate. Even the supersonic Concorde was subject to the same taxiing delays endured by the slowest turboprops in New York, London and Paris.

The problems often aren't with the flight times, they're with the block times. That's why Gerard Arpey, CEO of American Airlines, recently told shareholders his carrier was making "strategic adjustments" in an effort to improve customer service. He was quoted as saying: "Among other things, we adjusted the way we schedule our aircraft, flight attendants and pilots. We increased our block times, as well as the time planes spend on the ground between flights in many instances." The result? According to the U.S. Department of Transportation, American's on-time performance for the 12 months ending in April was 74.2%, up from 67.2% during the same period a year ago.

American is not the only airline that has increased block times. In fact, throughout the year airlines continue to expand and contract—though they usually expand—the length of time you're scheduled to be onboard. So you may have a greater chance of arriving on time now. Even if it takes longer to get there.

Who reports delays?

Among regulators, aviation analysts, consumer advocates, journalists and travel agents, the DOT's monthly Air Travel Consumer Report is the foundation for all who evaluate the airline industry's customer service performance. Twelve times a year, the report's extensive charts detail the on-time performance of the nation's largest carriers, and that information is used in countless ratings and rankings.