Even as they struggle mightily at home, airlines that fly to Europe and Asia are seeing some of their highest passenger loads and revenue in years. That's good news for the airlines; not so good for business travelers.

Many airlines saw demand for flights to Asia last year drop off significantly due in large part to the weakened economy and severe acute respiratory syndrome. European flights were affected by the Iraq war.

Now U.S. businesses seem to be making up for the drop-off. According to a recent survey of the 2,500 business travel managers who make up the Association of Corporate Travel Executives, 69 percent said their companies are doing more traveling to Europe and Asia this summer than last.

And since low-fare U.S. carriers aren't yet flying to Asia or Europe, the carriers that are can charge some premium rates. United Airlines' revenue per passenger mile to Asia, for example, increased 57 percent last month from the same period last year. In the travel manager survey, 62 percent of those who responded said they were having trouble finding low fares.

Marcella Axley, travel manager for Fair Lawn, N.J.-based Lonza Inc., said that her company is doing about 25 percent more international flying this year compared with last and that fares are about 10 percent higher.

She said her biggest challenge is finding business-class seats, especially on flights to China, where the chemical manufacturer has a plant. And because Lonza didn't do much international flying last year, Axley said, the company doesn't have negotiated rates with the airlines.

Schneider Electric, in Palatine, Ill., is requiring its employees who fly to Asia and Europe to book as many as 21 days in advance if they want to fly business class. "There's not always availability if you book within seven days," said Schneider's travel manager, Amanda Jackson.

Jackson said the company is doing 70 percent more flying to Asia this year and 30 percent more flying to Europe. To offset its growing international travel demand, Jackson said, the company is reducing the amount of domestic travel.

Last month, United saw its highest revenue and passenger loads ever on flights to Asia. "Over the last two or three months, we've been very surprised," said Graham Atkinson, senior vice president of United's worldwide sales and alliances.

Atkinson said most of its flights to Hong Kong and China from the United States have been more than 80 percent full. In June, due to the increased demand, the airline launched three new flights to Beijing, Osaka and Zurich from San Francisco, Chicago and Washington's Dulles International Airport, respectively.

"The international routes are definitely offsetting the weakness in domestic routes," he said.

Bob Cortelyou, vice president of scheduling for Continental Airlines, said increased demand prompted the carrier to add flights to Paris, Rome and Amsterdam this summer. The airline also reinstated its Newark-to Hong Kong service, which it eliminated last summer.

Registered Traveler at National: Last week, American Airlines contacted more than 2,000 of its Washington area frequent fliers who use Reagan National Airport at least once a week, looking for people willing to try the registered traveler program that begins at the airport later this month.

The registered traveler program allows frequent fliers a quicker pass through security using a dedicated line and eliminates the chances that they will be picked for random security searches. American is teaming with the federal government to find Washington volunteers for the 90-day trial program, which began last month at Los Angeles International Airport.

The Transportation Security Administration will determine which passengers are selected. Travelers who sign up will find out if they're picked for the program within eight days. Interested travelers will have to undergo "security assessment" background checks, which include checking their names against government terrorist lists and looking for outstanding warrants, said TSA spokeswoman Amy Von Walter. Before they can enroll, they must submit to fingerprinting and a scan of their irises, and provide two forms of government-issued identification as well as their birth date and address.

Some of Washington's most frequent fliers, of course, are members of Congress, so American spokesman Tim Wagner said there's a good chance that some lawmakers might be asked to participate in the tryout. Rep. James L. Oberstar (D-Minn.) has already signed up in Minneapolis, said his spokesman, Jim Berard.

Many Washington area frequent fliers who have become frustrated with the long security lines and arriving at the airport 90 minutes before their flights said they plan to sign up if asked. They say giving the government their personal information is worth the ease of passing through security.

Lyndon Richardson flies about three times a month as a compliance officer for Capital One. Richardson said he had to go through similar background checks for his job.

"For those of us who have nothing to hide, this is a minor inconvenience," Richardson said. "Anything that can get us through security quicker is worth it."

Dennis Thorseth of Crofton said he'd even consider giving "blood samples or DNA" to have a separate security line.

But Gerald Mann of Alexandria said that before he gives up personal information, he wants an "ironclad" assurance from the airlines and the TSA that he would be able to skip the security lines and the X-ray machines and would no longer have to remove his shoes.

That's not how it's going to work, though. Registered travelers still have to pass through security, said the TSA's Von Walter. It's just that they will have a designated line.

While Von Walter insists that the information will be used only for airline security, some travelers remain skeptical.

"What a lot of people don't realize is that information could be used for anything the government wants to use it for," said Toni Ballentine, a marketing director for OAG Worldwide, a global flight schedule database company in Downers Grove, Ill. "I'd never be willing to give up what little privacy I have left, least of all to the U.S. government."

Question of the Week: Last weekend, an American Airlines flight crew prevented two passengers from boarding a flight because a crew member considered a T-shirt worn by one of them obscene. BizClass wants to know, do you believe that a traveler's attire, or personal hygiene issues, should be factors in whether the passenger is permitted on a flight? Please send your comments, along with your name and a daytime number, to alexanderk@washpost.com.