Federal officials alarmed by a spate of near-collisions involving airliners are trying to learn why air traffic controllers and pilots are making so many dangerous errors.
In recent months, there have been at least a half-dozen incidents in which airliners came close to colliding with other planes or helicopters. The incidents happened in Chicago, Houston, San Francisco, Burbank and Anchorage. In some cases, pilots made last-second changes in direction after cockpit alarms went off warning of an impending crash.
The FAA has also seen a sharp spike in incidents in which planes violated minimum separation distances, a cornerstone of air traffic safety. The rate for the most egregious violations of FAA separation standards rose to 3.28 per million flight operations in the nine months ending June 30, up from 2.44 in the full year ending Sept. 30, 2009. Flight operations include takeoffs, landings and when planes pass from the control of one radar center to another. It's the job of air traffic controllers to keep planes separated.