It's become a rite of passage, literally, for anyone who travels by airplane. You pass through a doorframe-like metal detector that beeps when loose change dares to pass beneath it. You place your carefully packed belongings onto an ominous conveyer belt that draws the bags into a dark netherworld to be X-rayed and inspected. But there was a time, only thirty years ago, when passengers could walk straight from the ticket counter to the tarmac and onto the plane without being stopped. As Annie Wu reports from Washington, airport security has evolved as the dangers in society have grown.

The History of Airport Security
by Annie Wu

The plane had just taken off from Portland when a dark haired man handed a note to the stewardess. He demanded $200,000 or else he'd blow up the plane with the explosives in his bag. The airline agreed to hand over the money. Then, the man who'd purchased a ticket under the name Dan Cooper lowered the stairs at the back of the plane and parachuted down, along with his loot, into the stormy darkness. He's never been found. But his story has become a folk legend, inspiring a movie and a Waylon Jennings song.

Jennings: "I like livin' easy, I like bein' free / Livin' free & easy brings out the best in me / Makes me shine Shine shine shine, makes me shine / With a little luck & a greenback dollar / You're gonna see me shine..."

Following the infamous D.B. Cooper skyjacking in 1971, aircraft makers created a device called a "Cooper Vane", that made it impossible to lower the rear stairs during flight. That's just one of many changes mandated by the Federal Aviation Administration over the years in response to increasing security problems. A year earlier, for example, in September 1970, Palestinians threatened to destroy four hijacked airplanes, two of them American.

In response, President Nixon put "sky marshals" on select flights to deter hijackers. David Leach was one of the first sky marshals. He says back then, commercial flying was still a novelty.

Leach: "And a lot of people were fascinated with the fact that there was a lavatory onboard an airplane. In those days, the lavatory was at the front of the airplane adjacent to the cockpit door. And these people would walk down the aisle; they'd grab the cockpit door and start shaking it. And my partner and I, we'd put our hands on our guns and look at each other and say, 'Oh no. Don't tell me this is it. This is it. The guy's trying to get into the cockpit.' And then they'd inevitably see the sign 'Lavatory,' go in there, and we'd just kind of sit back and say, 'Wow.'"

But sky marshals couldn't ride on every flight, and the hijackings didn't end. So in December 1972, the FAA gave the airlines one month to begin searching all passengers and their bags. Dennis O'Madigan, then Director of Security for Piedmont Airlines, says metal detectors known as magnetometers were rigged up from a device originally used by loggers.

O'Madigan: "If the metal remained in the log and the saw hit the metal, the saw was severely damaged and brought a halt to the sawing of the lumber. And so they came up with this device. And we simply took it and turned it into the magnetometers."

Some passengers found themselves stumbling through the new metal detectors, says David Leach who's now with the FAA's Security Office.

Leach: "Some of them were like tunnels, like 4 or 5 ft long, and they had to walk up a little ramp and down a little ramp. And we used to watch people fall into them and watch people fall out of them. It was really strange."

Leach also remembers that consumer advocates worried the metal detectors could be dangerous, until a study determined they gave off less radiation than a luminous dial on a watch. Instead, Leach says, the more critical question that took the FAA to court was whether the machines violated the Fourth Amendment, the protection against illegal searches and seizures.

Leach: "The courts, very fortunately for us and for the traveling public, made the determination that yes, it was a violation of the fourth amendment, but it was acceptable to the courts with two provisos. One, that it be applied universally so there's no chance of any discrimination, and two, that the search be limited to looking for weapons and explosives."

The policy of universal searches added on top of the hijackings and bombings changed the tenor of air travel forever, says Dennis O'Madigan with Piedmont Airlines.

O'Madigan: "Many people considered the airlines to be kind of romantic. The meal service was good. People dressed in suits or in dresses. So now that people realized they were going to have to submit themselves and their bags and anything else they brought on the plane to search, that did not enhance the early 60's romantic approach that the passenger had when they boarded an airplane."

The next big wave of security measures came more than 15 years later. Just before Christmas 1988, a bomb onboard Pan Am flight 103 over Lockerbie, Scotland killed 270 people. In response, the FAA began to screen portable computers and radios more carefully on flights from Europe and the Middle East. It also required that only bags accompanied by a passenger may board a plane. Still, it's not easy to protect a thin aluminum aircraft flying at 30,000 feet, says Irish Flynn with the FAA.

Flynn: "And into those aircraft go hundreds of millions of people every year. And billions of objects go into those aircraft. And our challenge is to ensure that things that are dangerous, lethally dangerous, don't go aboard those aircraft."

Until recently, the FAA has usually taken steps to improve air safety as a reaction to a hijacking or a bombing. Today, the government says it's planning ahead, for example, developing ways for airlines to deal with hijackers armed with chemical or biological weapons. In the meantime, the FAA hopes that passengers will be tolerant of airport security measures. Because while it may be the hundredth time you've heard the question, "Has anyone unknown to you asked you to carry an item on this flight?", the FAA reminds you that they're just trying to provide security in a dangerous world. From Washington, I'm Annie Wu for The Savvy Traveler.