11.   Airplanes are much more predictable.

12.   Airplanes are not the only things that fly, however.

13.   Airplanes have not been kind to the Kennedy family.

14.   Airplanes are also the latest fad.

15.   Airplanes may be next, they said.

16.   Airplanes were a novelty.

17.   Airplanes are most vulnerable as they approach landing, because they are flying slowly and at low altitudes.

18.   Airline officials said they announced the cancellations because of staffing problems and so many airplanes were out of position.

19.   Airplanes are targets.

20.   Also, the closer it gets to the long Labor Day weekend, the more crowded all airplanes will be.