11.   The government has twice grounded crop dusters because of fear they could be used to spray germs or chemicals over large areas.

12.   The government grounded crop-dusting planes temporarily because of what it found.

13.   The Philippine government has grounded a domestic airline for allowing a company officer who was not certified to fly one of its planes, an official said Friday.

14.   The U.S. government grounded crop-dusting airplanes for several days after the attacks.