Minutes after takeoff in the close confines of an airline cabin, a loud-mouthed passenger demands a beer and shoves an attendant. Other passengers gasp.
A federal air marshal, one of thousands at work since the terrorist attacks, approaches, identifies himself and tells the man to calm down. Instead, the man mouths off. Explosively, without warning, the air marshal grabs the man by the head, yanks him face-first to the floor, handcuffs him and shouts to passengers to remain seated and calm.
Jarring and fearsome, the staged incident was part of a training session by the Federal Air Marshals service. It was performed for reporters recently at the secretive agency's training center near Atlantic City, to reassure and educate travelers about the things they one day might witness in the skies.
"We want to get the message out that we're enforcing laws up there, which has not always been the case," said Greg McLaughlin, deputy director of the Federal Air Marshal service, a branch of the new Transportation Security Administration.
The service faces a delicate task since the terrorist attacks. Revamped and expanded essentially into an undercover airborne police force, the service tries to watch for and contain any kind of disturbance that conceivably could threaten any of the roughly 35,000 domestic and international U.S. flights daily.
In some cases the plainclothes marshals even act like regular police, such as helping collar a suspected money launderer and assisting a baby with burst eardrums. Almost every day, somewhere around the country, somebody is being arrested by a federal air marshal.
But the broadened mission has shocked people, too. Aviation security experts say most passengers are unaccustomed to seeing a forceful police action at their elbows in an airline cabin. And the vast majority of air marshals, no matter what their previous experience, are rookies at in-flight law enforcement.
One complaint came from Bob Rajcoomar, 54, a physician of Indian descent from Lake Worth, who filed a lawsuit notice in federal court alleging air marshals illegally detained him on Aug. 31 because of his skin color after his flight landed in Philadelphia from Atlanta.
On the same Delta Flight 442, two air marshals, later identified as Sammuel Mumma and Shawn McCullers, held the cabin at gunpoint for a half-hour after subduing an unruly passenger. Rajcoomar and the unruly man were released without charge.
The TSA, which initially defended the air marshals, has since ordered its inspectors to review the incident. While declining to comment on the case, acting Undersecretary of Transportation James Loy has promised "appropriate corrective action" if problems are found. The Transportation Department also plans to audit the service this month.
Critics believe they know the main problem: training or procedures _ or both. One Delta passenger, Philadelphia Common Pleas Court Judge James Lineberger, a former Army captain, said he thought the air marshals overreacted.
An aviation security researcher, Andrew Thomas, said air marshals too often consider simple "air rage" a possible diversion by hijackers.
At the training center, extreme precaution is exactly the point.
In a marksmanship demonstration, a two-person team is seated in a mock airline cabin when suddenly hijackers _ cardboard cutouts _ leap from lavatories. Wordlessly, air marshals pull their Sig Saur P229 handguns and, without standing, fire live bullets over the airline seats and flawlessly hit the targets.
Rising, one air marshal clasping her gun with two hands turns and shouts to the cabin, "Police, do not move! Keep your hands on top of your head! Remain calm!"
The other air marshal inches forward into first class, fires more shots, then tosses out a plastic-foam dummy after shouting "Coming out with Tango" _ terrorist.
"The goal is to get control of the aircraft," McLaughlin said, explaining that orders adapted to an airliner are in theory no different than ones police use on the ground. "If I'm telling you to move, it's not a discussion. When we need passengers' help, we'll ask for it. We're all closed into this aluminum tube until we get on the ground and we have to establish control and reduce panic."
But knowing how is different than knowing when and if to subdue someone. It requires split-second judgment, which trainers try to teach in classrooms and staged scenarios.
"We try to put people in as many situations as we can so they gain that judgment. You can't overreact, but you also cannot underreact," McLaughlin said. "A lot of judgment, I personally believe, just comes from experience" on the job.
Most air marshals have been at work less than a year. Thousands were hired in the last year, up from 33 on Sept. 11, 2001.
The agency also upgraded its monitoring operations and watches every flight in the country minute-by-minute from a high-tech center near Atlantic City. A poster on a wall shows Lower Manhattan above the words: "Never Forget. Never Forgive."
Training was abbreviated after Sept. 11 to get as many into the air as possible. The "expedited hiring" period is finished and air marshals must return at some point to complete the 10-week course.
"In any kind of expedited hiring, you will find you hired people who are not living up to the requirements. And with the speed at which we hired, (our) percentage may have been a bit more," McLaughlin said. "But the vast majority are very professional."