U.S. airline passengers near the security checkpoint can be searched any time and no longer can refuse consent by leaving the airport, the nation's largest federal appeals court ruled Friday.

The decision (.pdf) by the 9th U.S. Circuit Court of Appeals overturned the circuit's 34-year-old precedent that over time was evolving toward limiting when passengers could refuse a search and leave the airport after they had checked their bags or placed items on the security screening X-ray machine. Citing threats of terrorism, the court ruled passengers give up all rights to be free of warrantless searches once a "passenger places hand luggage on a conveyor belt for inspection" or "passes though a magnetometer."

"…Requiring that a potential passenger be allowed to revoke consent to an ongoing airport security search makes little sense in a post-9/11 world," Judge Carlos Bea wrote for the unanimous 15-judge panel. "Such a rule would afford terrorists multiple opportunities to attempt to penetrate airport security by 'electing not to fly' on the cusp of detection until a vulnerable portal is found."

The U.S. Supreme Court has never squarely addressed the limits of the Fourth Amendment in the context of airport searches. The attorney representing a man imprisoned for drug possession who tried to leave the airport rather than be searched is weighing whether to petition the justices to review the decision.

The case concerns Daniel Aukai, a Hawaiian man arrested with 50 grams of methamphetamine at the Honolulu International Airport in 2003. After he passed the initial screening station to board a flight to Kona, Hawaii, he was placed in a secondary search, as required by government protocol, because he did not have identification. He refused the search and asked to leave. Transportation Security Officials searched him and discovered the drugs and a glass pipe.

He was handed 70 months. (See Ryan's story from last year.) The sentence was upheld by the San Francisco appeals court.

"This is a post-9/11-bunker mentality," said Aukai's attorney, Pamela O'Leary Tower of Honolulu. "He said 'I want to leave.' The purpose of an airport search is to keep people off planes with bombs. The opinion seems to gut that."

In 1973, the circuit court ruled that airport searches were valid "only if they recognize the right of a person to avoid search by electing not to board the aircraft." In later rulings, the court began backing off, ruling passengers could not opt out of searches if they had checked luggage or if carry-on items were flagged during the initial screening to enter the terminal area.

The case is United States v. Aukai, 04-10226.