Frontier Airlines jetliners sit at gates along the A concourse at Denver International Airport. (David Zalubowski/ AP)

(This post has been updated.)

Frontier Airlines announced Tuesday that it will begin non-stop service to 14 new destinations, including Chicago, Las Vegas and Tampa, from Dulles International Airport.

The expansion is a boost for Dulles, where the number of domestic flights has steadily decreased over the past few years. The number of domestic passengers traveling through Dulles decreased to 14.7 million between January 2013 and January 2014, a 6 percent drop. While some blamed weather for the decline in travel, the number of passengers at Dulles has been declining for several years.

“The addition of Frontier to the Dulles family represents a significant, positive development for passengers interested in additional low-cost domestic travel options to and from the National Capital Region,” said Jack Potter, president and chief executive officer of the Metropolitan Washington Airports Authority, which manages Dulles and Reagan National airports, in a written statement. “With the Washington area economy growing and the Metrorail Silver Line on its way, Dulles will continue to fill the expanding air travel needs for the region and these new options from Frontier will play and important role.”

To kick off the new flights, the airline is offering special $15-each-way fares (note the price does not include taxes and fees) taxes and fees included from Dulles to the new destinations. Travelers who want to book flights need to move quickly: The sale will only be on for 12-hours and applies to travel through Nov. 19.  Additional introductory fares as low as $39 each way (again, this doesn’t include taxes and fees) will be available for booking through May 17. And have patience — when we tried to access the website (hey, we like cheap fares just as much as anyone) we were unable to access it. When we tried again at 12:45 p.m. the site appeared to be back online. But others say they are getting error messages. A Frontier Airlines spokeswoman said they are aware of the problem.

Direct service to Atlanta, Charlotte, Orlando, Minneapolis/St. Paul, Chicago and Tampa will begin in August. Service to Cincinnati, Detroit, Fort Lauderdale, Las Vegas, Memphis, Fort Myers, St. Louis and St. Augustine/Jacksonville (Fla.) will begin in September. One might wonder how Frontier is able to offer such low fares. It turns out the airline recently changed its fare structure, so that travelers may find themselves paying a la carte for services that used to be free. For example, the airline is now charging as much as $50 for placing bags in the overhead bin depending on which fare you purchase. See details here.  Frontier is a Denver-based low-cost carrier. It also offers service from Reagan National and Baltimore-Washington Thurgood Marshall International airports.