Full-body scanners that reveal what's hidden under your clothing and million-dollar machines that analyze air puffs for traces of explosives are not the first line of defense that keeps terrorists from getting aboard an airplane.
The front-line defenders remain the airport screeners — the men and women who guide you through those machines — and their training varies greatly throughout the world.
The Transportation Security Administration says America's airport screeners are the cream of the crop. "TSA's officers are our greatest investment and we provide them with a significant amount of training, both before they start working in airports and after they're on the job," spokesman Greg Soule said in a statement to FoxNews.com. "We rely on the top notch people, training, and technology to keep the aviation system safe."
But critics say America's airport screeners are undereducated, undertrained and ill-equipped compared to their counterparts in other developed nations. And that, they say, puts American passengers at greater risk.
The requirements for the job are a "reflection of the fact that we have not professionalized the field," says Andrew Thomas, an aviation security expert and editor of the Journal of Transportation Security. He has called for an academic, degree-based program for potential screeners.
"There's no assurance that [screeners] are in fact possessing the requisite skills, knowledge and background to do that job," Thomas told FoxNews.com. 'There's nothing in there about aviation security."
To become one of the nation's roughly 49,000 full- and part-time transportation security officers (TSOs), applicants must be U.S. citizens or U.S. nationals, possess a high school diploma or have at least one year of full-time experience working in security, aviation screening or as an X-ray technician.
Screeners must be proficient in "reading, writing, speaking and listening" and undergo up to 100 hours of classroom and on-the-job training.
They must pass drug and alcohol screening for marijuana, cocaine, opiates, phencyclidine and amphetamines. They must complete a medical evaluation, be able to lift and carry up to 70 pounds, have "customer service" skills and be able to "maintain focus and awareness" within stressful environments. Being able to walk up to two miles per shift is another prerequisite.
Successful candidates, who start at roughly $12 per hour and can earn up to $43,357 annually, must also pass a credit check and be less than $7,500 in debt, be clear of any delinquent federal or state taxes and not have any past-due child support payments.
According to TSA officials, more than 50 percent of TSOs have been employed by the agency for more than five years, and 25 percent are U.S. veterans.
Key skills, according to the TSA's Web site, are the ability to learn the "theories, dynamics and factors" in the aviation screening process, operating X-ray machines, working with persons of diverse backgrounds and communicating "non-technical" information effectively to others.
Those are specific criteria, but critics say the skill set doesn't match the job.
Thomas, who blasted the requirements as an "absolute joke," said U.S. screeners should be required to have secondary language skills — as is the case in many other nations — as part of a "globalized" field like aviation security. He also noted the lack of an "apprentice program" for aspiring screenes.
"Basic customer service skills are for a customer service job, and that's how they're treating it," Thomas said. "More important is the tangible ability to understand aviation security. That needs to be taught."
An airport screener's role is "completely different" in Israel, says Rafi Ron, former security director at Israel's Ben Gurion International Airport.
"The main role is not the screening aspect so much as it is conducting interviews, and that calls for a completely different set of skills," Ron told FoxNews.com. "They're not screeners, they're profilers."
Ron said the typical Israeli airport screener is 21 years old, possesses a "strong, curious" personality, has completed military service and undergoes up to nine weeks of training before employment. Pay reportedly begins at about $11 per hour.
"The kind of people who we look for are above average intelligence, so when they run interviews they are not easily impressed [with potential security risks]," he said. "That leads to a very interesting and a very different approach."
A large percentage of the workforce are students, Ron said, and are typically not employed longer than five years.
"Because of the need for curiosity, after a few years, you get burnt out," he said. "You lose your curiosity. [Screeners] don't it make it a career."
In Belgium, screeners must be citizens and be fluent in French and Dutch, unlike the one-language requirement in the U.S. Basic training includes 40 hours of instruction and up to 64 hours on various aviation security fields such as X-ray machines. Successful candidates are then paid roughly $15 per hour, according to a 2000 report on aviation security by the U.S. General Accountability Office.
Screeners in the Netherlands are also required to be fluent in two languages — Dutch and English — and are trained initially to become general security officers before receiving specialized training to be certified as checkpoint screeners. At least 40 hours of training precedes two months of on-the-job instruction and 24 hours of additional instruction annually.
Canadian screeners, according to GAO figures, must be fluent in either French or English and receive 20 hours of classroom training in addition to 40 hours of on-the-job training. Once certified by the government, individuals must pass written and practical tests every two years to remain on the job.
Douglas Laird, former security director for Northwest Airlines, said the amount of training hours screeners receive in Europe typically "far exceeds" the hours of instruction screeners receive in the United States.
"There's no comparison," Laird said. "And what you find in Europe, the screeners stay employed much longer than in the United States. It's more of a career."
He said the amount of training in the United States is not inadequate, but additional hours would undoubtedly produce a "better product."
"The concept is good, but to be effective, you need hundreds of hours," Laird said. "You have to have people who really understand the process."
The best screeners, regardless of which airport they protect, develop an "innate sense" of whom to search and whom to pass through to the gate, Laird said.
"You need to be able to look at a crowded screen and determine what you're concerned with and cut out the noise," he said. "Some people can't do it very well."