"It's more unusual because it's a hurricane and not a snowstorm," said Bob McAdoo, an Imperial Capital analyst in Los Angeles. "A hurricane affects the infrastructure a little differently. A lot of the people that work at the airport need public transit to get to work. Without those people, the airport could be open but you won't see commercial flights operating."
Mayor Michael Bloomberg said New York's subways may not open for five days, while New Jersey Gov, Chris Christie, R, said restoring Port Authority Trans-Hudson train service to Manhattan may take as long as 10 days.
Officials conducted damage assessments at New York's John F. Kennedy International and LaGuardia airports and New Jersey's Newark Liberty, Ron Marsico, a spokesman for the Port Authority of New York & New Jersey, said in an e-mail. New York Gov. Andrew Cuomo, D, told reporters he doesn't expect LaGuardia to open Wednesday either.
About 15 percent of U.S. flights from Friday through late Monday were canceled due to Sandy, based on data compiled by Portland, Ore.-based researcher FlightStats. For weather events since 2005, that ranked second only to the 16 percent rate for a December 2010 New York snowstorm, the data show.
At least 720 U.S. flights are already scrubbed for Wednesday, Houston-based FlightAware said on its website. Cancellations for Sunday through Thursday now total 16,234, according to FlightAware's tally.
US Airways has no flights Tuesday to New York, Washington's Reagan National Airport or its Philadelphia hub, said Todd Lehmacher, a spokesman. The carrier canceled 1,600 of the day's flights, or about half the schedule, he said.
United isn't flying to its Newark hub Tuesday, and Delta isn't sure when service can resume at New York-area airports, spokesmen for the airlines said.
JetBlue Airways, which has its largest base at Kennedy, is awaiting an update on damage at New York airports and is ready to resume operations there Wednesday afternoon, said Mateo Lleras, a spokesman.
"The availability of public transportation will also play into the New York plan," Lleras said. "It remains very, very fluid."
JetBlue expects to resume partial operations at Washington and Boston later Tuesday, Lleras said.
Airlines must now work on rebooking passengers and positioning planes and crew to restart flights. Michael Boyd, president of consultant Boyd Group International in Evergreen, Colo., estimated Monday that the U.S. industry would lose $100 million in revenue from the storm.
"The thing that is going to determine how much more significant this is, is how long the recovery period is," Ray Neidl, a Maxim Group analyst based in New York, said in a phone interview Tuesday from his home.
Flights may resume on a limited basis Tuesday at Washington's two main airports, Dulles International and Reagan National, and at Baltimore Washington International, spokesmen for those facilities said.
Terminals are open at Boston Logan, and airlines will be rebuilding their schedules through tomorrow after a "significantly reduced operation" on Tuesday, said Matt Brelis, spokesman for the Massachusetts Port Authority.
At Chicago O'Hare International, airlines canceled more than 270 flights to and from the East Coast, while at Midway International airlines scrubbed almost 70 of those flights as of 7:30 a.m., Karen Pride, spokeswoman at the Chicago Department of Aviation, said in a phone interview.
Sandy's toll is already greater than Hurricane Irene's in August 2011, when that storm took aim at New York and triggered flight cutbacks along the East Coast. Over six days, airlines cut 8.5 percent of their flights, based on the data from FlightStats.
The cancellation rate for Sandy through Monday topped the 13 percent for a January 2011 ice storm that belted the U.S. Southeast, including Delta's Atlanta hub; the 10 percent for a February 2010 storm in the northern U.S.; and the 5.4 percent from the 2007 Valentine's Day ice storm that crippled JetBlue Airways's operations, the data showed.
By volume, the Sandy-related cancellations were still short of the 22,441 that FlightStats tallied for the February 2010 storm. Those were amassed over a 10-day period.