The recent attacks in Brussels have again raised the question of what can be done to counter the terror threat to airports. How can airport security be improved?
Airport security systems were designed in the late 1970s in response to a number of commercial aircraft hijackings around that time. Forty years later these systems remain relatively unchanged. Passenger screening primarily focuses on detecting concealed metal objects. Human operators continue to play a key role in the process by monitoring baggage scanners, conducting body scans with metal detection wands, conducting physical searches, and now taking chemical swabs of hand luggage.
The September 11 attacks, which still cast a long shadow over today's airport security efforts, sidestepped these screening systems by using permitted items (box cutters for example) as improvised weapons to carry out the hijackings. More recently, screening systems were rendered worthless with a front-of-house attack in Brussels.
The issue remains that airport security procedures are predictable, taking place at a single, fixed point during a passenger’s journey through an airport. What is required is a system sufficiently flexible to meet anticipated security threats with timely and appropriate responses.
Resources should be focused on making airport security systems smarter and more flexible, not necessarily more extensive. Good security does not mean having to wait a long time in queues.
Much of the airport security debate is concerned with the effectiveness of this passenger scanning process. Subsequent to a specific transatlantic flight plot in 2006, there have been various efforts to improve the effectiveness of the scanning process. More effort has been made to educate passengers on the rules (clear plastic bags, electronics in a separate tray, belts and bulky shoes off, is breastmilk a liquid?). The process is slow, inefficient and has an air of security theatre - designed to portray safety to travellers, when, like at Brussels, the main threat can be before this security curtain.
Does Behavioural Profiling at Airport Checkpoints Work?
In 2011 the TSA launched the $878M pilot SPOT programme in the United States to gauge the effectiveness of behavioural profiling. The practice involves selecting passengers for additional screening due to body language or behavioural indicators. As part of the trial program, every traveller passing through Boston’s Logan Airport Terminal A was subjected to about 20 seconds of behaviour detection procedures - just simple questions such as “Where are you heading today?” or “How long have you been in town?”. Analysts don’t look for the answers necessarily but instead gauge the reaction, with those deemed of interest pulled aside for further screening.
The technique was pioneered at Tel Aviv’s Ben Gurion airport, where officials think of passenger security as a series of concentric circles, with increasing scrutiny as individuals arrive closer to the plane. To illustrate, all vehicles that arrive at the airport must first pass through a preliminary security checkpoint where guards search the vehicle and exchange a few words with the occupants as the first stage profiling. Vehicles are also examined with a weight sensor, a backscatter x-ray and an under vehicle scan. During the next layer of security, plain clothes officers patrol the area surrounding the terminal, assisted by hidden closed-circuit cameras with sophisticated analytics.
However, a report from the Government Accountability Office (GAO) in 2013 stated that behavioural profiling at airports is simply not effective. In its 100-page report, the GOA explains that the TSA used unreliable data to set-up the original program. Damningly, the report concluded that the behaviour identified by profilers was hugely inconsistent and varied wildly between airports. In other words, there was a high degree of subjectivity and not much science in explanations given to justify additional attention on certain passengers.
So what more can be done to assist with profile threat assessments? Another source of intelligence is the Computer-Assisted Passenger Prescreening System (CAPPS). When a ticket is purchased, CAPPS rates passenger risk using approximately forty characteristics such as credit history, destination, travel companions, payment type, flight time and purpose of travel. Algorithms are then employed to screen those identified as high risk.
The implementation of a worldwide one-stop one-stamp travel history profile could add more data to the profile. This simple change would mean immigration officers stamping passports for every border crossing in sequential order, instead of the haphazard approach currently taken. When you know what you are looking for, such a simple reading of a person's travel history could be an invaluable source of intelligence.
Finally, it is important to look at how this security information is integrated. As a traveller naturally has many points of contact with an airport (from booking the ticket, parking the car, the baggage check-in through to the final boarding card inspection) there are many opportunities to build an informed intelligence picture and perform threat assessments of individual passengers. In the future, every contact point will be used to add to this intelligence; all the information associated with a boarding pass, vehicle registration, CAPPS score, behavioural markers, heat signatures and even facial recognition will be integrated into a single-source and readily accessible to security staff as passengers are tracked for the entirety of their journey through the airport.
Until the human factors are considered in the design of airport security procedures, technological responses will fail to meet their objectives
The current method of screening passengers requires that operators perform a task at which the human brain is proven to struggle. That is, a visual search task aimed at detecting very rare occurrences amongst an infinite array of very similar backgrounds. Humans, however, have vastly superior capabilities compared to even the most sophisticated computer system when it comes to pattern recognition, spatial visualisation and abstract reasoning.
In an attempt to overcome the limitations of the human brain, which is expected to perform accurately and reliably day after day, the Screener Proficiency Evaluation and Reporting System (SPEARS) has been implemented at many airports. This technology provides more regular feedback to screeners and their supervisors through the random insertion (via software) of threat object images into scans. The reports produced on operator performance can be used to diagnosing weaknesses and create more effective, individually tailored training programmes. They also provide criteria for validating job suitability for applicants and candidate selection.
A similar method of increasing accountability for security staff is through the use of body-worn video cameras. Body cameras give a user eye view, which is often greatly superior to eye-in-the-sky CCTV. Whilst improving evidence collection, body cameras also provide an excellent analysis tool for identifying patterns of behaviour in security staff, can decrease staff complaints and reduce aggravation in stressful locations.
How can airport security be improved?
Passenger clearance and security in the main terminal building, which has been the main focus of this blog are only a small piece of the airport security mosaic. Other areas such as maintenance, baggage handling, retail, perimeter security and freight all have their own risks and require their own specific approach. It was members of the cleaning staff that stashed grenades in the plane’s toilet to facilitate the hijacking of TWA Flight 847 in 1985. In the future, security system analysts will likely have to contend with ever more sophisticated cyber attacks aimed at airport IT infrastructure, including air traffic control, while the possibility of a major drone incident taking place is also, unfortunately, all the more pressing - leading to some very innovative drone counter-measures.
The reality is that when it comes to the defence of critical national infrastructure such as airports, there are no guarantees. The aim is to minimise vulnerability by making a target less attractive and by making security less predictable – because then the terrorist finds it harder to create a viable operational plan. It’s clear that to improve airport security, resources should be focused on making airport security systems smarter and more flexible, not necessarily more extensive. Good security need not mean having to wait a long time in queues. A summary of some of the suggestions here includes:
- Security to begin further away from the terminal building, starting at access points including car parking.
- A mixture of uniformed personnel, canine teams and plain clothes officers in and around the terminal, backed by camera surveillance operators and advanced analytics.
- Improved ambience at pinch points - terminal entrances, security and passport clearing.
- Training for airport employees to detect suspicious travellers profiles at every passenger contact point.
- Security teams of highly-selected, cross-trained, motivated personnel performing appropriate tasks, with continuing measurement and feedback of their performance.
- A selection of integrated technologies and databases that can be called upon quickly to identify and counter probable threats.
- Timely intelligence continuously dispersed to security teams on probable adversaries and threat scenarios.
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