Airline Late by Date   (Feb2010)

The chart at right shows how each of the major U.S. airlines performed by day for the month.  You can drill down to the level of specific flight numbers if you're interested.

Late by Origin   (Feb2010)

The chart at right shows where the ontime and late flights originated.  Note: open the chart controls on the left side of the image, and the click play or drag the slider to see the chart animate.

Service by City   (Feb 2010)

This chart shows which airports have the combination of strong schedules (lots of flights=bigger circle on the chart) AND good on-time performance (intense blue in color).  

Living on the west coast clearly has benefits for frequent travelers.

Overall Ontime by Cxr   (Feb2010)

As the charts above show, reliability has a lot to do with WHERE you are flying TO/FROM.  Since each airline flies a different network, aggregate comparisons sometimes don't tell the whole story.  So, caveat emptor.  But, here are the aggregate performance facts about the majors.

I've put up several more datasets and charts on the subject, using the tags "airline" and/or "travel."