The U.S. and Europe are both attempting to modernize air-traffic control, but they could end up using different technology. Officials from the Federal Aviation Administration and the European Aviation Safety Agency gathered to chart a course for coordinated efforts. "I am greatly concerned about divergent paths. ... If we aren't diligent, we are going to lose this opportunity" to create systems that complement each other, said John Hickey, an FAA safety official. Some estimates indicate U.S. airlines may spend approximately $20 billion through 2030 on new, NextGen equipment. However, carriers want to realize benefits from the significant investments already made before considering further investments.