Do airlines pad out times to improve rankings?

Airport congestion, tighter airspace and the weather make air travel variable

Brett Snyder, founder of the air travel assistance site Cranky Concierge, addresses the oft-suspected question of whether airlines pad out flight times in order to improve their on-time rankings. Passengers may be suspicious of why, according to the times on their tickets, a flight between Los Angeles and New York appears to take longer today than it did 30 years ago. But the reasons for the differences in are different. Factors like airport congestion, tighter airspace and the weather have all made air travel far more variable than it used to be, forcing airlines to make departure times earlier than the real take-off times. Scheduling in the 21st century is a tricky business, making flight times highly variable even from week to week.
Often, if airlines use flight-time padding at all, it is for the short term while temporary congestion problems are solved. Meanwhile, airlines operating on the same routes sometimes show different flight lengths, as different aircraft are used, each with different optimum cruising speeds and taxi speeds.
CNN
[pictured: Stockholm Arlanda; photo by Kenneth Hellman, courtesy Stockholm Arlanda Airport]