United Airlines, the airline offering the most nonstop flights from New York/Newark and the Washington, D.C., metropolitan area, is adding daily trans-Atlantic summer-season service between:
New York/Newark and Athens, Greece, from May 25 through Oct. 5, 2016
Washington/Dulles and Barcelona, Spain, from May 25 through Sept. 6, 2016
Washington/Dulles and Lisbon, Portugal, May 25 through Sept....