According to the FAA, all prospective air traffic controllers "must have the capacity to perform the essential functions of these positions without risk to themselves or others. Candidates must be physically and mentally fit and meet standards for vision, hearing, cardiovascular, neurological and psychiatric health."

The current ATC system "is based on an outdated technologies that are unable to meet" modern demands, an administration statement said.

When the agency approved moving Newark air traffic controllers to Philadelphia, it said the odds of a dangerous communications breakdown was about 1 in 11 million.