PaxEx FAQ: How Do Airport Security and Screening Methods Work?


    Image: Danjo Paluska via Flickr

    APEX Insight: Even airline CEOs, aerospace manufacturers and aircraft interior designers have some unanswered questions when it comes to the passenger experience industry. In this installment of PaxEx FAQs, APEX Media takes a closer look at the technology behind evolving airport screening methods.

    The United States has lifted the controversial ban, announced in March, prohibiting large electronics in the cabin of direct flights to the United States from 10 specific airports. In its place, the Department of Homeland Security has implemented enhanced security measures for all commercial flights to the US, including heightened screening of electronic devices that may require passengers at security checkpoints to remove larger devices from bags for separate screening and perhaps power them on and off.

    On Wednesday, the Transportation Security Administration (TSA) announced new rules that will require travelers at US airports to place electronic items larger than mobile phones in a separate bin for screening. The TSA is also operating automated screening lanes, designed to enhance security effectiveness while decreasing waiting time, in some terminals at John F. Kennedy, Newark Liberty, Hartsfield-Jackson, Atlanta, O’Hare and Lost Angeles international airports.

    These days, a trip through an airport security checkpoint might involve X-rays, pat-downs, swabbing, sniffing, powering up electronics, and more. What’s new and how do some of these tools work?

    What’s In the Bag?

    At most airports, carry-on bags pass through X-ray machines on conveyor belts, while checked bags get the once-over by more sophisticated computed tomography (CT) scanners that shoot hundreds of images of a bag using an X-ray camera to create 3-D images that can be rotated for easier viewing. The TSA has recently starting testing smaller, checkpoint-sized CT scanners at some airports.

    Walk This Way

    At airport security checkpoints, the TSA uses both walk-through metal detectors and millimeter wave advanced imaging technology (also known as body scanners) to screen passengers.

    Walk-through metal detectors use an electro-magnetic coil to create a magnetic field that is disrupted when another piece of metal is introduced, like a gun or a belt buckle, explains Jeff Price, professor of Aviation Management at Metropolitan State University of Denver, and lead author of the textbook, Practical Aviation Security.

    Millimeter wave machines (or full-body scanners) have been at most airports since the early 2000s. According to the TSA, the machines’ automated target recognition software doesn’t produce passenger specific-images (like the ill-fated, invasive backscatter technology) but instead uses technology that auto-detects potential threats by indicating where something may be amiss on a generic outline of a person. They work by “bouncing radio waves off a person to provide a virtual X-ray,” said Price, “They are not x-raying passengers; the radio waves that are used are on the opposite end of the spectrum.”


    After a TSA officer swabs a passenger’s hands or electronics at the security checkpoint, the sample is placed in an Explosive Trace Detector (ETD), which analyzes it for microscopic traces of explosive residue that can live on a person’s hands, clothes, equipment or baggage for days after they’ve handled certain chemicals. Most EDT machines work by heating up the samples and testing the vapors for traces of specific chemicals.


    Passengers may find themselves being sniffed by working dogs at airports more often than in the past. State and local law enforcement often patrol airports with canines, but, thanks in part to extra funding by Congress in the FY 2017 appropriations, the TSA has been expanding its canine teams and stepping up its use of bomb-sniffing dogs at airports. “The dogs are sniffing passengers and their belongings for potential explosive devices,” says Price. “Many started out in air cargo, but are now an additional layer of security.”

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