Interesting story about the tarmac delays and cancelled flights, which I read in The Baltimore Sun ("Canceled flights climbing," July 21). The airlines "warned" us that many flights would be cancelled if this regulation was passed. I wonder if some of the airlines are being over-zealous in cancelling these flights in the first few months of implementation to show the worst-case scenario.

Even so, I am surprised that the writer did not question the math of aviation consultant Darryl Jenkins, who may have had a vested interest in the study. He said: "Here's the bottom line: They [federal officials] predicted 41 cancellations per year, and after one month we saw more than 140. So, they're off by a factor of 10."

No, that's not a factor of 10. A increase by a factor of 10 would be 410 cancellations, instead of the predicted 41. Actually, the prediction was off by a factor of 3.4. By allowing him to exaggerate, it makes the situation — though worse than predicted — sound far worse than it is.

Chris Gunty, Arlington, VA