Federal aviation officials lifted the ban on commercial and private air travel Thursday, clearing the runway for flights in and out of Kansas City International Airport.
Six of the major airlines with operations at KCI were open for business by Thursday afternoon. Two more are expected to resume operations today.
Continental Airlines is not expected to resume its flights until Tuesday.
Existing flights are limited, and it's unclear when or if they'll return to normal.
"Our schedule is reduced by about one-third," said Brandy King, a spokeswoman for Southwest Airlines. "At this point, we haven't set a date for things being back on track."
Federal officials shut down the nation's airways Tuesday, shortly after terrorist attacks in New York and Washington, D.C.
Rick Weintraub, a spokesman for US Airways, said most airlines used Thursday to "build back up and get new (security) procedures in place."
He, too, declined to say when flight schedules would return to normal.
"Once crews get repositioned, you're going to see a rapid ratcheting up of the learning curve," as crews become familiar with new schedules and security procedures, he said. "It won't take long, but it's still a number of days away. I don't know how many."
Airline officials strongly encouraged passengers to confirm their flights before leaving for the airport.
Also, passengers are being asked to arrive two hours before their flights depart.
"Most people are accustomed to getting here an hour or half an hour before their flight leaves, but we're asking everybody to arrive two hours early," said Erica Hupp, a spokeswoman for KCI. "It's going to take longer to get through security."
Changes in security procedures include:
l No more curbside parking. Drivers will not be allowed leave their vehicles.
l No more curbside luggage check-in.
l All passengers must check in at their airline's main ticket counter.
l Passengers will be required to show photo identification for boarding or checking luggage.
l No pocket knives or knifelike objects will be allowed on board.
l Passengers will be asked to limit their carry-on luggage.
l Only passengers will be allowed in the waiting-room areas.
"We're asking friends and relatives to say their goodbyes outside the secured areas, Hupp said. "And once a passenger enters the secured area, they're not to leave. So if you want to get a Coke, get it before you check whatever it is you're carrying on. It's going to be difficult to go back and forth."
Those picking up passengers at the airport will be asked to arrive 10 or 15 minutes late, Hupp said, because they won't be allowed to park or wait outside in their cars.
"You'll still be able to pick people up, but it will have to be done quickly," she said. "You're not going to be allowed to park and go inside to find somebody or to help them with their luggage."
Those arriving early to pick up passengers will be directed to either the nearby parking lot or garage.
"The first 30 minutes is free," Hupp said. KCI parking facilities have room for 17,300 vehicles.
At Lawrence Municipal Airport, spokesman Lloyd Hetrick said the U.S. Department of Transportation has not lifted its ban on noncommercial flights.
"We're open but, really, there's not much going on because we don't do all that much 'commercial,'" Hetrick said. "We have a few charters come in and out, but that's about it."