A potted history of luggage screening

Early air passengers boarded without screening and very few restrictions on what could be taken on to the plane. By the 1980s and 1990s, metal detectors and X-ray equipment were introduced to combat the growth in terrorism.

In 1999 ECAC Standard 1 laid down the certification and testing procedures for hold baggage explosive detection systems (EDS). The objective was to ensure EDS could accurately detect a broad range of explosives whilst minimising false alarms. These systems were early examples of certified, automatic detection algorithms in the screening process.

Computed tomography

EDS Hold Baggage systems meeting the updated and revised Standards 3, 3.1 and 3.2. (2015 onwards) are certified for fully automated, alarm only viewing - therefore, only images raising an alarm are diverted for inspection by operators. This was made possible by developments in computed tomography (CT) systems which could be deployed as the primary screening technology - previously CT had only been used for alarm resolution. Having been successfully deployed for several years, this concept is now well proven and soon to become a reality at the passenger checkpoint.

3D images

By 2016, ECAC was developing EDS standards for cabin baggage with a choice of compliance options - EDS CB C1, C2 and C3. Requiring the then newly developed checkpoint CT X-ray scanners, C3 offers the highest level of automation. CT scanners spin around the object and take hundreds of images at slightly different angles to deliver a detailed 3D image, allowing for more accurate judgments on the bag contents. This technology relies on detection algorithms and allows electronic devices, liquids and gels to be left in hand baggage for X-ray screening – taking checkpoint security closer to fully automated, alarm only viewing.

APIDS certification underway

Access to cabin baggage (and potential weapons) mid-flight makes checkpoint screening particularly complex. Advances in AI based algorithms have enabled real-time, automatic identification of a fast-growing range of prohibited items: for example, firearms, sharps (such as knives & scissors), axes, grenades, blasting caps, ammunition and blunt objects. They can already be used to support image analysts by framing any suspect items – the next stage is certification for a new CONOPS.

The EU ECAC APIDS Standards certify the algorithms which automate the process of image analysis. According to Smiths, there will be three standards, each increasing in levels of detection; and decreasing in percentage of mandatory random alarms. APIDS standards will be combined with ECAC EDS CB standards to permit different degrees of automation and allow a gradual move towards alarm-only viewing.

Testing for APIDS Standard 1 is underway; only systems with EDS CB C1, C2 or C3 approval are eligible for testing and Smiths Detection Icmore APIDS algorithms are being tested together with the Hi-Scan 6040 CTIX, Hi-Scan 6040aTiX and Hi-Scan 6040-2is HR. Further EDS scanners will follow as each algorithm has to be tested in combination with specific hardware. Standard 2 certifications are likely to follow within months on Standard 1.

APIDS Standard 3 will provide certification for alarm only viewing plus 10% random alarms. It will require scanners pre-approved for the forthcoming EDS CB C4 which will almost certainly be restricted to CT based equipment.

Keeping pace with perpetrators

Regulators are looking for continuous improvements in security which can only be achieved by taking advantage of new technology, including using AI for object recognition. Deploying the latest technology can also significantly reduce or eliminate the need for additional, random search requirements such as metal detectors or bag search etc.

Algorithms do not need breaks, get tired or make mistakes and they are 100% impartial – they do not have a ‘bad day’ or personal issues which can impact performance. They reduce the insider threat and in trials, have been seen to outperform image analysts.

Full automation with alarm only viewing has more than proved itself in hold baggage screening and with additional certified algorithms to spot cabin threats (such as weapons), it should be equally effective at the passenger checkpoint. In addition to higher levels of security and a more streamlined screening process, automation has a positive impact on staff deployment and operational expenditure. To reap the full benefits of APIDS and achieve operational savings, Icmore APIDS needs to be combined with centralised screening to allow optimum utilisation of screener resources.

And in future….

The challenge, according to Smiths Detection,  will be to respond proportionately and appropriately in developing security measures.

Security is about mitigating risk and regulators will increasingly work together with suppliers to understand and evaluate likely threats; establish the best technical solutions to address those threats; and develop new regulatory standards.

APIDS certification underlines that AI and automation are the way forward and will continue to play a key role in aviation security. Once certified, algorithms cannot be changed without recertification. However, it is relatively straightforward to develop additional detection algorithms as needed to address new and evolving threats.