Hurricane Sandy grounds 12,500 flights nationwide

Hurricane Sandy disrupted air travel across the United States, grounding about 12,500 flights Monday and today as the storm barreled toward the Northeast and forced the region's major airports to suspend operations.

Some airlines began extending cancellations through Wednesday as the storm's track became clearer. Scrubbed flights totaled 7,670 Monday and more than 4,800 Tuesday, according to FlightAware, a Houston-based industry data provider. Counting flights grounded Sunday, the tally reaches 13,785.

United Continental, Delta Air Lines and American Airlines cut their schedules as carriers halted virtually all service to New York, Washington and Philadelphia. New York's three airports make up the nation's busiest air-travel market, so the upheaval rippled throughout the United States and curbed international service as well.

"If you are flying in or out of the East Coast today or tomorrow, you are out of luck," said Keith Gerr, a spokesman for industry researcher FlightStats.com. "Anyone transiting through major hubs like San Francisco, Chicago and Dallas-Fort Worth will experience high delays and cancels."

Cancellations ahead of severe weather keep planes, passengers and crew members out of harm's way, and let airlines position jets to restart flights quickly once the danger passes. While carriers save on fuel and maintenance in such cases, they still must pay crews and rebooking expenses, and some customers won't reschedule their scrapped flights.

JetBlue Airways, which has its largest base of operations at New York's Kennedy, is joining local authorities in watching for any flooding at the region's airports. New York's LaGuardia and New Jersey's Newark Liberty are the other two large airports in the area.

"Airport infrastructure must be operational before we even think about starting operations up again," said Mateo Lleras, a spokesman. "Public transportation is a close second. We have to be able to get our crew members to the airport."

The New York-based carrier canceled 1,200 flights from Sunday night through Wednesday morning and suspended operations at the New York airports and Boston, cities that are touched by 70 percent of its flights, Lleras said.

Those markets, along with Washington and Philadelphia, were a focus of cancellations by United, Delta, American, Southwest and US Airways. American said it was possible that its pullback may extend beyond Wednesday.