Case Study

United Kingdom

The UK’s Digital X-Ray Competency Testing Transformation

An up-to-date certification process is crucial to ensuring that those at the core of aviation security screening have the skills needed to perform effectively. In the UK, within the context of changes to the regulatory regime and the screening technology available, the extant certification system found itself in need of review. As part of a strategic change, in partnership with Rapiscan, the introduction of the Digital National X-Ray Competency Test helped to transform the process used by the UK CAA and industry. This case study highlights some key benefits brought by the project, and includes learnings and tips for Regulators with a similar need for modernisation.

Transforming Screener Certification: A Bold Step Towards Innovation

In 2022, The UK’s Department for Transport (DfT) and Civil Aviation Authority (CAA) were seeking a partnership with a third-party provider to develop a replacement for the National X-Ray Competency Test (NXCT). The pace of technological change within aviation security, especially the increasing use of 3D screening, meant that the incumbent test was no longer appropriate for all screeners. Furthermore, the UK CAA had a desire to improve the efficiency of its screener certification system, including ensuring the test was more accessible for all users.  

The proposed replacement would be designated the Digital National X-ray Competency Test (DNXCT). It would be a web-based application accessible via the principal web browsers (Edge, Chrome, Safari, and Firefox) with no local installation requirement. It would cover all relevant operational environments, including 3D image testing. In line with the UK CAA’s charging principles, DNXCT would be a cash-neutral product, with entities (airports, cargo-regulated agents, and training providers) paying a fee per assessment to cover the cost of the DNXCT. 

The UK's Journey to Screener Certification Modernisation

The UK had a vision for screener certification. This vision was to facilitate a robust and valid assessment system in line with international and national regulatory requirements whilst going beyond compliance to support industry to improve screening standards. The DNXCT product has allowed the UK to comprehensively meet this goal. 

How was this achieved?

  • Defining RequirementsThe UK aimed to enhance its national assessment by making it more valid, accessible, and data-driven. The CAA required a high-quality, robust system that supported both 2D and 3D screening across various modes, including In Flight Supplies (IFS). It needed to be online, scalable nationwide, and capable of operating in areas with limited broadband.
  • Building the System – In partnership with Rapiscan and the Department for Transport, development began in October 2022. Built from the ground up, the UK Digital X-ray Competency Test (DXCT™) is now a customisable, off-the-shelf solution for global regulators. The system draws on deep UK and Rapiscan expertise, retained for ongoing support.
  • User Testing – Industry involvement was central. The system was shaped through collaborative working groups with the Regulator, DfT, industry, and Rapiscan, ensuring it met real-world needs and was robustly acceptance tested.
  • Setting the Pass Mark — pilot with selected partners helped determine a balanced pass mark—avoiding both security gaps and unnecessary operational burden from excessive retraining.
  • Deploying the Test – Launched in August 2023, the system rolled out smoothly via a phased approach. With minimal issues at go-live, it quickly gained industry confidence, supported closely by CAA and Rapiscan.
  • Embedding and Managing the System – DNXCT has had zero unplanned downtime and offers live remote access to detailed test data. The CAA uses this for internal reporting, industry updates, and performance analysis. The data supports compliance, oversight, and trend identification—offering significant long-term value.

Themes of Improvement

The UK screener certification transformation project brought many improvements. 

Assessment Validity:

  • Goal: Moving towards a test that is representative of operational reality
  • Problem: Outdated image banks, no 3D images, test locally installed limiting operational flexibility
  • Solution: 7 specific assessments across 4 screening modes, 3D and 2D images, X-Ray correct images (energy maps, not screenshots), clear/search/threat disposal decisions, robust scoring system in the backend, online access.

Data:

  • Goal: Creating a test where data points can be accessed and evaluated
  • Problem: No immediate data access, limited data availability
  • Solution: Dashboard and reporting, full test data available, exportable and integrable, can be shared.

Malpractice and Security:

  • Goal: Ensuring that the certification regime is designed to discourage malpractice
  • Problem: Avoidance of malpractice, such as trainees sitting tests on behalf of each other, or receiving assistance during the test
  • Solution: Authentication key required from Test Manager, data traceable through the system for invigilators and candidates, IP allow-listing, secure image bank.

Regulatory Transformation:

  • Goal: Maintaining the correct regulatory provisions to manage the risk
  • Problem: Test requirements not outlined within regulation, too stringent requirements on Test Managers, cumbersome approval process
  • Solution: Streamlining and digitalisation of Test Manager approval, realignment of the approval requirements with the actual need and risk, and addition of more specific regulations on testing. 

Cybersecurity:

  • Goal: Ensuring the certification system kept pace with modern cyber security requirements
  • Problem: Emergent cyber risks linked to updating to an online system with more held data
  • Solution: Robustly defined requirements and implemented features, Multi-factor Authentication, IP allow-listing

Performance Data

From a test performance perspective, the UK certification system has been performing exceptionally. Quality assuring the test itself is a very important part of maintaining effective certification, and the UK approach points towards a highly successful testing system.  

Tens of thousands of users have registered on the system, taken assessments, and been awarded certifications. The UK can have a high level of confidence that all screeners who pass the test have an appropriately high standard of competency in image-based interpretation at the time of certification, and hence confidence in the human element of the screening system.  

Furthermore, screeners undertaking assessments have achieved an average score across all tests that meet the baseline standard and risk requirements of the UK appropriate authority.  

There are over 38,000 hours of assessment time recorded in the system, and the system has shown capability to deliver 32,000 images per hour. 

Conclusion

DNXCT has played a crucial role in helping the UK align with the International Civil Aviation Organisation’s (ICAO) Global Aviation Security Plan (GASeP). 

For example, under “Enhance risk awareness and response”, the system’s ability to track screener performance at a range of levels means that vulnerabilities can be addressed in a proactive manner. And under “Improve technological resources and foster innovation”, the digital certification process and test manager approval process have given greater accuracy and efficiency. The data now available to the UK CAA also meet priority area 5: “Improve oversight and quality assurance” – screener performance data can be used to link into compliance activity and risk assessment.  

By reinforcing these critical GASeP pillars, the digital screener certification system strengthens the UK’s role in upholding the integrity of global aviation security. 

The UK case study demonstrates both the critical importance of screener certification to aviation security and the transformative benefits the installation of the DXCT product can bring. The UK system was designed to meet exacting regulatory requirements based on educational expertise and feeds into a positive security culture and professionalisation, where certification is viewed as a valuable tool to drive up standards.  

These foci, alongside the ample evidence of the system’s success, mean that the UK Regulator can have confidence that their image-based assessment is a valid test of competency and that screeners in the UK system are sufficiently skilled. The assurance of screener competency in this way directly leads to improvement in screening standards –  CAA International and Rapiscan have the shared goals of driving up certification standards globally, following the exemplary UK model.  

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Top Tip! Test Design

When designing an image-based assessment, it is important to consider the operational reality of the screener, to keep the test fair and valid. Consideration should be given to the timing of the test, the user interface, available enhancements, and other screening aids such as threat boxes. There is always a balance to be reached between matching the operational aspects with the pure threat identification element of testing.

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Top Tip! User Data

Certification systems are in place to confirm that the screener’s relevant competencies are in place. There will have to be some collection of personal data in the execution of a certification programme, however with respect to data protection needs, this personal data should be appropriately limited. When setting up a certification system, it is important to remain cognisant of relevant data protection legislation and consider carefully the appropriate user data to be recorded

The UK has a high level of confidence that all screeners who pass the test have the appropriately high standard of competency in image-based interpretation, and hence confidence in the human element of the screening system.

UK Civil Aviation Authority

Elevate Your X-ray Screening Standards with Next-Gen Competency Testing

Launched in 2024, DXCT™ is a cutting-edge X-ray screening competency testing solution, purpose-built for ICAO Member States and National Aviation Authorities. Developed with Rapiscan and based on the UK’s Digital National X-Ray Competency Test framework, it offers a scalable online platform to standardise and elevate screener performance.

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