Q. I was booked on flight from Dallas to Birmingham, Alabama and it was canceled. When I asked a counter agent why, they said it was because there were not enough passengers for the flight. We were rebooked on next flight, six hours later. When I contacted the airline's customers relations department they stated that the flight was canceled due to mechanical problems, and they gave me an eVoucher for $200. I also asked for an earlier return flight, and had them waive the change fee of $150. My question: could an airline cancel a flight just because there aren't enough passengers, and do you think the customer relations people were loathe to admit it and changed the cause to mechanical problems?

A. We've heard rumors for years that airlines cancel flights because there aren't enough passengers, but even if these tales are true no airline would ever admit to it. Canceling for that reason just doesn't make much sense to us. Most planes are scheduled to go to other destinations in the airline's system, so canceling a flight has consequences down the line. In your case, American's flight to Birmingham was probably going to fly right back to Dallas, but canceling still would have impacted passengers waiting for it at the other end. Also, flights are so full these days that it's hard to believe one was canceled for lack of passengers.