Jetliners will travel new routes above the Eastern United States beginning today, raising the likelihood of on-time flights but giving air traffic controllers new concerns over staffing and training. The Expanded East Coast Plan, in the works for five years, is part of a grand plan the Federal Aviation Administration says will simplify air routes, improve monitoring, reduce departure delays and handle more flights. The plan covers airspace south from Maine to Miami and west to Chicago, an FAA announcement said. Officials said a similar plan is being developed for the West Coast. Some air traffic controllers in the New York area say they are understaffed and insufficiently trained for the new system.