[Avionics Magazine 09-08-2016] The European Aviation Safety Agency (EASA) is in the process of reviewing the Surveillance Performance and Interoperability (SPI) regulation, which could impact Automatic Dependent Surveillance-Broadcast (ADS-B) regulation in Europe. EASA’s revision of the Commission Implementing Regulation (EU) No. 1207/2011 laying down requirements for the performance and the interoperability of surveillance for the Single European Sky (SPI IR) could have a significant impact on how commercial, business and general aviation aircraft operators retrofit their aircraft with ADS-B Out avionics moving forward.
London Stansted Airport. Photo: NATS Press Office.
The European Commission originally adopted the SPI IR and Aircraft Identification (ACID) rules in 2011, to facilitate Europe’s transition to new surveillance technologies and application to improve overall efficiency in the region’s Air Traffic Management (ATM) system. Data reported in 2015 (through State Local Single Sky Implementation tool) shows that SPI and ACID requirements (Regulation (EU) 1207/2011, 1028/2014 and Regulation (EU) 1206/2011) will be fully implemented in 2020, in Europe.
“Performance requirements are stipulated in these two regulations and amendments. For example, SPI stipulates that aircraft operating Instrument Flight Rules/General Air Traffic (IFR/GAT) in Europe and with a maximum certified take-off mass exceeding 5,700 kg (12,500 pounds) or having a maximum cruising true airspeed capability greater than 250 knots are required to carry and operate Mode S Level 2s transponder(s) with Mode S Elementary Surveillance (ELS), Enhanced Surveillance (EHS) (for fixed wing aircraft) and ADS-B 1090 MHz Extended Squitter (ES) capabilities. The applicability dates for this requirement is June 8, 2016 for aircraft with an individual certificate of airworthiness first issued on or after June 8, 2016; and June 7, 2020 for aircraft with an individual certificate of airworthiness first issued before June 8, 2016,” Eurocontrol’s surveillance engineering team told Avionics Magazine.
Eurocontrol recently released its Master Plan Level 3 2015 Implementation Report, with data indicating that the performance requirements for the surveillance function (SPI, ACID) will evolve over the next decade while the exact characteristics of the ground-based infrastructure are unknown. The report specifically states that the “choice of ADS-B based solutions for continental surveillance is limited,” and that major parts of the surveillance infrastructure needed to deliver the expected level of performance will be based on a combination of Wide-Area Multilateration (WAM) deployments in combination with legacy radar technology. The FAA defines WAM as a technology that provides surveillance through a network of small sensors deployed in remote areas, with specific capability to enable air traffic controllers to better track aircraft flying into and out of airports in mountainous areas with no radar coverage.
According to Eurocontrol, while there are performance requirements stipulated in the SPI and ACID regulations, the SPI legislation is not perspective, but only sets out performance requirements and accepts flexibility within the individual European state-based Air Navigation Service Provider’s (ANSP) choice of solutions to meet those requirements.
“The SPI regulation specifies requirements for common data format standards and type of surveillance data to achieve interoperability between the ground systems. The report suggests that major parts of the ground surveillance infrastructure that will deliver the expected level of performance will probably be based on WAM deployments in combination with the classical radar infrastructure. The concrete technology to be deployed will typically be determined through the investor’s assessment of the business case and the safety case for candidate solutions, as long as the chosen solution meets the interoperability requirements set by legislation. For instance, in the European region we continue to see further deployments of (costly) primary surveillance radar technology in the ATM domain, often because the safety performance requirements lead to such solutions,” Eurocontrol said.
Overall, the Single European Sky vision for ground surveillance is to combine ADS-B with independent surveillance within en-route and terminal areas and to focus on a performance-based rather than prescriptive modernization of the European ATM network, the Eurocontrol master plan notes. In August, SESAR JU released a detailed report regarding the continued evolution of surveillance service in Europe, which will serve as an input into the ongoing EASA SPI revision.
Related to its ongoing revision of the SPI regulation, the European Commission initiated a two-step remedial approach, including the publication of Regulation (EU) No. 1028/2014 with revised aircraft equipage mandates and a February 2016 launch of a formal EASA rule making task to conduct a detailed review of the SPI IR and then draft a revised regulation, according to an information notice published by the U.K.-based Civil Aviation Authority (CAA). The CAA notice also stated that EASA published an online survey designed to gather data from stakeholders within Europe’s 28 different ANSP-controlled airspace zones to gather data the agency considers critical to conducting a regulatory impact assessment and cost benefit analysis for a revised SPI regulation.
Eurocontrol’s master plan report notes that surveillance modernization in Europe is progressing in non-radar airspace with ground implementation of ADS-B as a sole means or together with multilateration using current certified equipment on board thousands of aircraft.
“ADS-B ground receivers are currently used but, in the near future, space-based ADS-B receivers may also be used,” the report said.
While the SPI regulation is still under review by EASA, Eurocontrol’s master plan report still indicates that most states in the ECAC region are currently in the process of targeting finalized implementation dates for SPI by 2020 and ACID by 2025. Regardless of the revision though, the use of ADS-B as a surveillance technology throughout Europe would require in-service aircraft to be upgraded with new ADS-B avionics.