JetBlue's new service to Boston means cheaper fares in Phila.

JetBlue Airways, the highly regarded, low-fare carrier, is coming to Philadelphia and trying to do what three other airlines couldn't: compete successfully with US Airways Group Inc. on a Boston-to-Philadelphia route.

The introductory fare for the five daily nonstops that begin May 23 is $17.76 - but you have to move quickly. That's the cost if you book at www.jetblue.com by 11:59 p.m. Dec. 14.

What makes JetBlue think it can succeed where Southwest, AirTran, and Delta failed?

"JetBlue has a much bigger presence in Boston, and they've developed a good corporate as well as student following," said Robert W. Mann, aviation consultant in Port Washington, N.Y.

"They have simply more feed and more coverage in the Boston market, more network available, and are much better positioned than AirTran or Southwest. And Delta's presence at Boston has wound down as JetBlue has expanded."

The $17.76 "independence" fare won't last - it's for travel between May 23 and June 19 and aims "to please all clam chowder and cheesesteak fans alike," JetBlue said, in announcing the new service Thursday.

Boston is a "focus" city for JetBlue, which has added about five new destinations a year since 2004. The carrier says it now serves more cities than any other airline from Boston Logan International Airport.

"Boston is a big hub for JetBlue, so they can offer onward flights to Long Beach, or San Juan, or Santo Domingo, or anywhere they fly," said George Hobica, founder of airfarewatchdog.com.

Passengers connecting through Boston can travel on JetBlue's partner airlines, including Aer Lingus, Icelandair, Japan Airlines, Lufthansa, and Virgin Atlantic, or throughout New England on Cape Air.

"They are just in a much better position to do this," Mann said. "I think it's a good opportunity for them."

And it's an opportunity for Philadelphia-area travelers.

US Airways has a monopoly on flights to Boston, after Southwest stopped flying there from here in February. In January, Southwest also dropped Philadelphia flights to Providence, R.I., and Manchester, N.H.

Airfares suddenly skyrocketed.

A check of US Airways' website for travel to Boston on Monday, Dec. 17, lists a $279 one-way nonstop coach seat, and a $647 return nonstop fare Thursday, Dec. 20. US Airways offers 19 weekday round-trips to Boston.

"Five JetBlue flights every day definitely beats a long drive, or the current air alternative," said Scott Laurence, JetBlue vice president of network planning. "We're pairing this convenient business schedule with fares accessible to all."

Philadelphia International Airport CEO Mark Gale said: "We are really, really excited about this. JetBlue is an award-winning airline. We don't have any competition on the Philly-Boston run right now - it's solely operated by US Airways."

"To have some competition on that route by a low-cost carrier, we believe ultimately is a great thing for the consumer and the users of our airport," Gale said.

Airport officials tried for years to snag JetBlue, based at New York's JFK International Airport, with 750 daily flights including to the Caribbean and Central America.

The perky carrier, with a reputation for customer friendliness, didn't bite - until now.

Although the $17.76 introductory fare - an ode to Philadelphia history - is fleeting, ticket prices should remain low.

JetBlue's website showed Thursday that when the $17 fare is no longer available, a one-way ticket ranged from $64 to $134.

Southwest launched flights to Boston in June 2010 with $59 one-way fares. Before dropping the route, the ticket price remained $79 each way.

Passengers can expect US Airways to match the JetBlue fares. US Airways matched Southwest fares when both carriers were flying there.

JetBlue flights to Boston will depart at 8:45 and 10:55 a.m. and 1:25, 5:25, and 8:25 p.m. daily.

Boston-to-Philadelphia flights will leave at 6:40, 8:45, and 11:24 a.m. and 3:15 and 6:10 p.m. daily.

"We are absolutely thrilled that travelers in the Philadelphia region will now have convenient access to JetBlue," Mayor Nutter said. "I want to congratulate JetBlue for recognizing the value of doing business with the Greater Philadelphia region and business community."

Philadelphia will be JetBlue's 78th city. The airline claims to offer travelers "uncommon perks," including a first free checked bag, more legroom in coach than any other U.S. airline, unlimited brand-name snacks and drinks, and seat-back entertainment that includes 36 channels of free DirecTV and more than 100 channels of free Sirius XM radio.

The airline, which will fly 100-seat Embraer E190 jets between the two cities, was named "top low-cost airline for customer satisfaction" by JD Power and Associates between 2007 and 2011.

JetBlue is the fourth airline to announce new service at Philadelphia airport this year. Virgin America and Alaska Airlines began flying to the West Coast in the spring. On April 4, Spirit Airlines will begin nonstop daily flights to Dallas-Fort Worth.

For consumers, the advantage of competition is lower fares. Airlines that have a monopoly on routes can charge what the market will bear.

When Southwest ended Boston flights, the airline said the route had not "performed the way that we would have liked." AirTran dropped service to Boston in 2007. Delta did so in 2009.

US Airways, with an international hub and 438 daily flights here, can make a profit, where Southwest might not, because US Airways gathers travelers from across the country, and brings them through Philadelphia, to 88 domestic and 26 international destinations.

US Airways does not rely solely on traffic that begins and ends journeys here.

at 215-854-2831 or lloyd@phillynews.com.