United Airlines will add three new domestic routes at its Denver hub. Daily flights to Greenville/Spartanburg, South Carolina, and Syracuse, New York, will begin June 6 and will operate year-round. Flights to Portland, Maine, start June 8, but they’ll operate only on weekends during the summer schedule. All three of the new routes will go head-to-head against service offered by Denver-based budget rival Frontier Airlines. The routes add to other previously announced United routes to Charleston,… (www.yahoo.com) 更多...