Kennedy Airport's busiest runway will be closed for about four months next year as part of a $204-million, three-year makeover, a prospect that airline industry officials are viewing worriedly at the huge airport that ranks near the top nationwide in flight delays. More than 2.75 miles long, Kennedy's Runway 13R-31L is one of the longest commercial runways in North America - second only in the United States to a runway at Denver International Airport. Last year, it handled more than 143,000 takeoffs and landings. Aviation and airline officials say delays stemming from the construction are inescapable, though no one can say now how much delays will increase. "The scope of the project is truly enormous," said William DeCota, director of aviation for the Port Authority of New York and New Jersey, which operates Kennedy, LaGuardia and Newark airports. "It provides for the replacement of almost three miles of asphalt pavement." The Port Authority has asked airlines to revise their schedules and has coordinated the 14,572-foot-long runway's reconstruction with the Federal Aviation Administration, which handles air traffic control, DeCota said. Air traffic controllers will have to adjust plane routing to Kennedy's three other runways and increased delays will occur, FAA spokeswoman Arlene Salac said. It is unlikely that airlines will shift flights to other area airports, she said. Not all of the airport's four runways are used simultaneously. Much depends on weather conditions - especially the wind, Salac said. Pilots prefer to take off and land going into the wind, so runway usage often is configured to take advantage of favorable wind conditions and to avoid crosswinds. The project to rehabilitate Runway 13R-31L, last resurfaced in 1993, begins this month with site preparation, and is expected to continue until November 2011. Much of the work prior to the runway's closure is to be done at night so that as little disruption as possible occurs. The runway is scheduled to be completely closed from March 1 through June 29, DeCota said, as construction crews remove 5 inches of the asphalt surface and replace it with more durable concrete. Perini Construction of California won the bid for the work. Company officials referred questions to the Port Authority. "It's important for our contractor to get this done on the schedule it has to be done," DeCota said. Flight delays have been a longtime problem for the Port Authority's airports. Among the nation's 31 largest airports, Kennedy ranked 29th for on-time arrivals and 28th for on-time departures in April, the latest figures available from the U.S. Department of Transportation. JetBlue Airlines - Kennedy's biggest domestic carrier, with 170 flights a day - is just beginning to analyze the effect the runway's closure will have on its flight schedule, spokeswoman Alyson Croyle said. The airline is using data from when Runway 4L-22R was closed at Kennedy for a month in April, Croyle said. "It certainly does have an impact on operations," she said. Delta Air Lines, second to JetBlue in the number of passengers going through Kennedy, is eager to learn from the FAA exactly how the closing will affect its flight schedule. David Castelveter, a spokesman for the Air Transport Association, a trade group that represents the nation's largest airlines, said the industry is searching for ways to minimize construction-related delays. "ATA and its members are concerned about 2010, and we are quite anxious to work more closely with both the Port Authority and Federal Aviation Administration to minimize the impact of the construction project," Castelveter said.