Park Air Systems Limited, a wholly owned subsidiary of Northrop Grumman, has over 50 years expertise in the design, manufacture and installation of ATC communications systems. Recent years have seen an increase in interest from air navigation service providers as they seek to more efficiently deploy their resources, especially across small airports, airfields and aerodromes. The upgrading of airfields in less-developed areas for commercial traffic provides real benefits to the local community and economy.
Widely referred to as remote tower concepts, these systems can enable airfield upgrades with a minimum of cost and environmental impact on the local site. By removing the need for a physical control tower, the civil works required for an airfield upgrade can be minimised to the surfacing of runways, the installation of masts and single storey buildings.
Park Air Systems Limited has released the customisable Small Aerodrome Air Traffic System (SAATS), which supports these developments by supplying VHF and/or UHF communications and basic meteorology systems in cabinets suitable for outdoor installation. The system is expandable with local and remote-control interfaces, suitable for renewable backup power systems and mast mounted cameras and sensors.
Park Air’s latest radio, the T6 from the Sapphire portfolio, is their most advanced product to date and is at the heart of the SAATS. SAATS combines the class leading performance of the T6 with a suite of complementary services to support remote locations across the globe.
In its most basic form, SAATS is supplied as an outdoor cabinet housing the class leading T6 VHF or UHF software defined radio, an S4 IP Controller, basic meteorology, masts, antennas and sensors. The latest evolution of the T6 range of professional ATC ground-to-air radios sets new standards for bringing high levels of safety, efficiency and performance into the smallest, lightest package Park Air has ever produced. To provide control from a remote tower system SAATS includes options for digital IP or traditional analogue interfaces for connections back to the control site.
As a last resort contingency, or for busier operational periods, SAATS can also be provided in a locally controlled configuration. A single Park Air S4 IP Controller can be connected directly to the radio channels providing full operational control, with main/standby radio pair configurable for automatic change-over. The S4 IP Controller delivers comprehensive remote operation of Park Air ground to air radios from single or multiple user positions and includes a touch screen, dual headset sockets and integrated loudspeaker.
Customers can add to this entry-level system to develop a solution suitable for their own aerodrome needs, or to continue to meet capacity as their aerodrome expands. Modular options can also be selected to provide multiplexor or VSAT interfaces. This minimalist approach allows customers to access advanced technological solutions at an affordable price point, which can then be customised to meet their specific requirements.
Size and power savings
Most remote and digital tower concepts revolve around IP systems. This leads to a real opportunity for integrators to virtualise multiple systems onto a small number of physical servers. The minimisation of the number of boxes required to build up a system allows for all of the control systems required for a local airfield to fit into one or two standard racks. Not only is this a saving on space, but also on the power requirements and thermal efficiency of the system. As the thermal efficiency of the system improves, it also decreases the air-cooling requirement and so further reduces running costs and infrastructure. The Park Air T6 range sets new standards for high efficiency and low power consumption, delivering the lowest possible running costs and through-life resource dependencies.
One of the greatest advantages of reducing the energy consumption of systems for small airfields is that it makes the use of local renewable energy systems for operations a real possibility. Park Air has successfully trialled the use of solar panels for back-up power, which takes pressure off power supply requirements in remote locations where power networks are known to be unreliable. If systems are consolidated onto servers designed for low power consumption, it is possible to approach a concept where the critical airfield systems can reliably run from a renewable energy source. This drastically increases the viability of sustaining critical operations as well as reducing the environmental impact of the airfield.
The logical continuation of the consolidation of systems and minimization of external infrastructure requirements is to ask why a building is required at all for these systems installations. Many other industries, by necessity, already house critical control systems in robust outdoor cabinets with their own independent power sources. If the aviation industry were to follow this lead then the requirements for a high-quality domestic airfield could be as low as having enough space and the availability of a telecommunications backhaul to a control centre. Everything else could be supplied as an integrated system with minimal ground works, outdoor cabinets, masts and sensors. Once again, Park Air are leading the way by deploying critical Air Traffic Control communication solutions in cabinets suitable for outdoor use.
When equipment is remotely located from operators and maintainers on an IP network it becomes even more important to consider system security. This includes on-site physical and procedural security, product cyber security, and network security. On-site security for unattended sites is something many air services providers are so used to that it is sometimes overlooked when considering system cyber security. However, the best network security can easily be undone by poor access control to critical components. Traditional site security is provided with a lockable outdoor cabinet similar to those already used in the rail industry. This can be enhanced with IP technologies providing network logging, alerting and live monitoring of site and cabinet access.
Cybersecurity
From a cyber security point of view a remote tower system can be considered as a series of subsystem blocks that have different levels of trust. The control centre and tower site subsystems would be considered higher trust areas as they can be designed and tightly controlled to an organisation’s security architecture. However, these two subsystems are connected by a wide area network, which may be supplied by another organisation or even run over a public network. This subsystem would be considered a lower trust area. It may be a challenge to be confident of the security of the lower trust subsystems. Instead the security of the interface between high and low trust subsystems can be given a higher focus, and technologies such as secure tunnelling used to pass data over untrusted subsystems.
The SAATS system is designed with this security philosophy in mind. The selfcontained remote site cabinet system is provided with physical security and alarms, and the products are combined with an eye to system level cybersecurity. The system interface with a wider IP network is provided through a managed layer three switch providing access restriction and capability for connecting to the control site via a virtual private network (VPN). Individual components within the SAATS systems are configured to limit the open ports and processes only to those necessary for the functioning of the system.
The Park Air designed products in the SAATS system are designed to provide a secure basis to the system. All software in Park Air products designed is developed and supported following quality procedures accredited against the ISO 27001 and TickIT+ standards. The operating system used in the T6 Radio is based on the open source Linux Kernel, which provides a worldwide pool of developers continually monitoring and improving the security of the platform. Only the part of the operating system required for radio operation are activated in the kernel, leading to lower resource requirements and a reduced attack surface on the final product. The radio specific software on the radio is continually developed to meet the latest security requirements, such as those in the recently released Eurocontrol Voice over IP Security Baseline standard.
The security benefits of continuously development of bespoke software and open source platforms are only useful if the software on site is regularly updated. Park Air supports this in the SAATS system with the availability of a software update service for their products that alerts maintainers when there is a new software update file available from the Park Air website. Software updates with the latest security fixes are provided multiple times per year. The service also includes a server based utility to install updates remotely to all network connected Park Air equipment simultaneously or in groups.
Ultimately, the SAATS system could enable a hub and spoke arrangement, whereby a single control centre is set up to be in charge of multiple airfields that would previously have been economically unviable to upgrade and operate as licenced airfields.
In large countries with many small remote communities, deploying such technologies and systems would lead to significant improvements in infrastructure and consequential benefits would be seen in better access to education, medical facilities and social care. Further benefits may also be seen in a growth in local business in those regions and in revenue for the operators of the airport services.
The development of SAATS typifies the continual investment in innovation undertaken at Park Air and the passion that exists for pushing the boundaries of possibilities in new areas of technology. Fiona Thompson, managing director of Park Air Systems states: “At Park Air we foster a culture of innovation. We continually invest in our products and our people to ensure we can deliver the best performing and most reliable solutions to our customers now, and for many years to come.”