They swarm over airplanes sitting at the gate - handling luggage, delivering meals, pumping fuel. They peer intently at X-rays when passengers pass through security control, and pass your keys in a little tray around metal-detecting machines.
They check tickets at the gate, assign seats, and deliver the bad news if a flight isn't on time.
They're the thousands of people who work at America's airports - and they may be one of the weak points in today's airline-security defenses.
The day-to-day activity of ground personnel at airports across the country is under scrutiny in the wake of the tragedy of TWA Flight 800. Dozens of workers can enter an airplane while it sits on the Tarmac between landings and takeoff. Many of them might have an opportunity to leave behind a bomb, experts say.
Investigators have yet to definitively determine if a bomb destroyed Flight 800 - or how a bomb might have gotten on the plane. While the vast majority of airport employees are honest and hard-working, terrorists might easily masquerade as baggage handlers, say - or suborn some other low-paid worker. A 1994 General Accounting Office (GAO) report found that the turnover rate for airport screeners was more than 50 percent and that screeners needed "better and more frequent training."
The trouble with these jobs, according to Joe Lawless, director of the Massachusetts Port Authority in charge of security at Boston's Logan International Airport, is the pay rate. "They don't make much over minimum wage. That's why the turnover rate is so high," he says.
Some 40 people reportedly had access to TWA Flight 800 while the plane sat in New York. James Kallstrom, head of the FBI's investigation into the crash, said in a recent news conference that the FBI has interviewed all those individuals, as well as all who had access to the plane in Athens before it flew to New York.
But a highly publicized theft last December from a bag being loaded onto a plane at Kennedy International Airport highlights the problem of access. A baggage handler stole a diamond necklace and bracelet belonging to Sarah Ferguson, the Duchess of York. The young man was later apprehended and the jewelry returned. But if workers can take something out of a bag during loading, they can just as easily put something in, experts say.
Certainly, airport workers are not the only soft spot in security.
"We highlighted a number of vulnerabilities in the overall security framework, such as the screening of checked baggage, mail, and cargo," GAO assistant comptroller Keith Fultz said in testimony before a Senate committee on Aug. 1. "More recent security concerns include smuggling bombs aboard aircraft in carry-on bags or on passengers," he added.
In interviews, spokesmen for three companies that provide 500 passenger screeners and cargo loaders for airlines at Logan Airport say that their turnover rate is extremely high, but that they don't keep figures. Most of their employees are students, retirees, or people who haven't been well-educated, they say.
But the companies do run 10-year background checks - both work history and criminal records - on each applicant, they say.
If the cause of the TWA downing is ruled to be a bomb, as expected, airport-security measures will most likely be bolstered - even more than the additional random checks President Clinton ordered July 25. Many experts and congressmen say that, while waiting for new baggage- and cargo-scanning technology to be tested, the US should adopt measures that have been in place for years in Europe and Israel.
"[US airport security] is a soft target right now, you want to make it hard," says John Beam, a security consultant and retired CIA official. "If you show that you are doing something, a would-be terrorist might go somewhere else."
Mr. Beam was in charge of setting up a security program for TWA in Europe. He modeled the program after one used by Israel's El Al airline, establishing security teams at each airport.
The first person a passenger encounters is a security agent, Beam says. That agent assesses the passenger and the ticket, and looks for certain things, such as whether the ticket was paid for in cash. If anything is remotely suspicious, the agent hands off the passenger to a supervisor for closer scrutiny. The supervisor questions the passenger more thoroughly and most likely inspects the passenger's bag and runs it through an X-ray machine.
This approach to security stopped Ann Murphy from unknowingly carrying a bomb aboard an El Al plane at London's Heathrow Airport in 1986. Ms. Murphy, who was traveling to Israel at the request of her Palestinian fianc in preparation for their marriage, followed his instructions to tell airport security she was going on vacation. But a security guard noticed her nervousness and handed her over to his supervisor. The supervisor discovered an explosive molded into the bag's lining.
Beam says two things will improve the quality of work for security personnel: Pay a decent wage, and motivate them. "They need to know that they're not just standing in front of an X-ray machine. They're part of a big defense team."