United Airlines will expand service from Newark-Liberty International and Washington Dulles airports starting this fall. The carrier will increase nonstop service between Newark and 15 destinations, as well as add new service to Palm Springs, Calif. and Key West.  Also, United said the changes to the Dulles schedule will offer more customers easy access to the capital and seamless connections to flights throughout the US, Canada, Europe, Asia and the Caribbean. Beginning in October, United will maximize services out of each hub by adding new destinations, additional frequencies and larger two-cabin aircraft. The adjustments are designed to offer more nonstop flights to destinations popular with New York area customers while reallocating largely connecting passenger flights on short-haul routes to Washington-Dulles. Toward that end, United will transition services between Newark and Chattanooga; Ithaca, N.Y., and Scranton, Penn. to Dulles.