Author: Andy Aldridge - Chief Engineer, Head of Technical Assurance - CHS Engineering Services Ltd
Deployment of Standard 3 HBS X-ray machines remains an important topic for many airports in the UK and Europe. The requirement defined in The European Commission passed a legislative framework requiring all hold baggage screening (HBS) in Europe be equipped with European Civil Aviation Conference (ECAC) Standard 3-approved explosives detection systems (EDS) by 2018 in the UK, 2020 for the rest of Europe and 2022 in specific circumstances.
Many larger UK airports have either completed the deployment or are in the final stages of deploying Standard 3 technology, however some smaller airports are just starting the process to do this.
CHS has been assisting several smaller UK airports to evaluate the impact of Standard 3 on their existing systems and what are the possible options open to them. The smaller regional airports are more constrained than larger airports especially in cost, impact on capacity and the physical fit and environmental machine requirements place on them. To explain further:
- Costs - Standard 3 machines are significantly more expensive to buy and maintain than the traditional Standard 2 X-ray units. In some cases, the procurement costs significantly exceed the available capital and maintenance budgets. It has come as a shock to some of the UK hub airports how much the operational and maintenance costs have risen.
- Capacity – Operational data from several sources shows a 10 to 15 % reduction in throughput between a Standard 3 X-ray and Standard 2. While this has limited impact at the smaller airports based on current throughput profiles, they must take account of this in any future increase in flights or changes to bigger aircraft expansion.
- Physical fitted and Environmental Constraints – The footprint of the Standard 3 is generally 15% larger and 35% heavier than the equivalent Standard 2 machine. Several regional airports cannot integrate some Standard 3 machines due to the physical size (it would require major build works to enable this). Also, some of the temperature, humidity and building vibration requirements are simply not achievable within the current building structure.
- Reject Rate - The Reject Rate/ False Alarm Rate of a Standard 3 X-ray machine was predicted to be 20% or lower, however the reality is it varies greatly between airport and even between HBS lines within a single facility. There are several factors which cause the variations such as;
- Which algorithm is being used (TSA or ECAC),
- Which version of the algorithm is in use?
- Type and contents profile of the bags being screened,
- The profile and destination of flights being screened.
CHS has gathered and analysed this data from multiple airports and was able to assist the client in understanding and mitigating the design risks and operating costs due to the potential impact of a variable reject rate.
CHS has also supported European airports and has just finish a piece of work for an airport in Stockholm. This involved helping them develop a suite of documents, so they could go to tender for both Standard 3 upgrades and Baggage System Capacity upgrades. While the airport has their own experienced inhouse project teams they felt they need an external input into deploying Standard 3 technologies to bring the learning from other airports who had already procure and installed the equipment
The work was to look at 4 airports within Sweden of various sizes, and while some requirements fitted all airports, some were unique to the individual airport especially around environmental and building constraints. One airport even has a protected building status which means, no structural changes are possible within the terminal building.
A series of workshops were held and enable the production of a generic procurement document for Standard 3 machines, plus a requirements document for the baggage system works.
The Stockholm airport are now proceeding with the procurement of the Standard 3 machines and project work utilising their own project teams with just the lightest support from external consultants.