US airports approached normalcy on Friday, which was "just like any other summer day," according to an Air Transport Assn. spokesperson, as UK Home Secretary John Reid said authorities now believe all the main players in the alleged plot to bomb aircraft flying transatlantic routes to the US have been arrested.Reid added that airport security will remain in a "critical" state to "err on the side of caution" in case some conspirators are still at large. UK authorities said they worked closely with Pakistan on the case, with the alleged plotters under surveillance for at least a month, and some reports suggested the counterterror operation had been ongoing for several months. Authorities in the US and UK said the attacks were possibly just days away from being carried out when the arrests were made Thursday.

By Thursday evening in the US, airlines and airports said they already were approaching normalcy. American Airlines said the number of itinerary changes or cancellations was "virtually insignificant from a statistical standpoint" and that the majority involved service to London.

Northwest Airlines said Friday that its operations had "significantly improved" from the day before. It did not have cancellations either day and was "urging customers to check all of their luggage for greater convenience and in an effort to minimize delays." It resumed carriage of unaccompanied minors and pets that was suspended on Aug. 10.

AirTran Airways said operations were "actually going very smoothly" and that it had no security-related cancellations. "Passengers are adjusting to the new regulations and many are checking bags, so we have had a slight increase in checked baggage," a spokesperson told ATWOnline.

JetBlue Airways said operations at New York JFK were going well and that it was relieved to get permission to continue offering to passengers traveling overnight its Shut-Eye amenity kit that includes lotion and lip balm. US Airways told this website that Friday featured "some delays, but not much more than normal," while Continental Airlines said the 34-min. average delay at Newark was due to high winds and that security screening was "not a big factor."

Airports also recovered quickly. Hartsfield-Jackson Atlanta said security checkpoint wait times were back to normal by lunchtime Friday and it was advising passengers that they could now arrive at the airport just 1 hr. prior to departure. Dallas/Fort Worth International said there were "minimal delays" on its 1,900 daily flights and that checkpoint lines averaged fewer than 10 min. Friday even as the airport's Dept. of Public Safety put additional units, dogs and explosives detection officers on duty.