3. The remote aerodrome ATS concept and modes of operation

The concept of remote aerodrome ATS enables provision of aerodrome ATS from locations/facilities without direct visual observation. Instead, provision of aerodrome ATS is based on a view of the aerodrome and its vicinity through means of technology. The primary change introduced by remote tower operations, compared to conventional tower operations, relates to the manner by which visual observation of the aerodrome and its vicinity is achieved. When operating from a remote tower facility, this is no longer carried out by direct out-of-the-window observation from a conventional tower. Instead, visual observation is achieved utilising a visual surveillance system, enabling situational awareness in accordance with Regulation (EU) 2017/373 [2] and ICAO Documents 4444 [7] and 9426 [8]. A remote tower can be located away from the aerodrome it is providing a service to, or it can be located in a building on or close to the aerodrome but without an adequate direct view of the area of responsibility. System elements of a visual surveillance system could also be introduced in a conventional tower, in order to enhance/complement situational awareness or to provide a visual presentation of parts of the aerodrome or its vicinity which is otherwise either inadequate or non-existent. The concept was initially introduced and developed within some Member States in the early 2000s and it has been further developed and refined within the SESAR JU programme. At the time of publication of this document, four so-called SESAR Solutions related to remote tower operations have been published by SESAR JU. (With reference to the European Operational Concept Validation Methodology (E-OCVM) [40], a SESAR Solution indicates that an operational concept has completed phase V3 of the Concept Lifecycle Model, thus being ready and mature for industrialisation (V4) and deployment (V5)). When it comes to remote aerodrome ATS, Japan has been providing AFIS from remote locations since 1974, although in the beginning only with a limited visual presentation of the aerodrome and its vicinity. The first remote tower implementation providing aerodrome ATS based on a situational awareness fully in accordance with ICAO Documents 4444 and 9426 was approved and introduced into operations in Sweden in 2015. Since then, several initiatives to provide remote aerodrome ATS have been introduced into operation, with an increasing number of initiatives being undertaken throughout Europe as well as worldwide. The concept of remote aerodrome ATS is constantly evolving and over time, since the concept was initially defined, the operational framework/target environments as well as new applications have evolved. It is expected that this evolution will continue. Results from research and development activities (such as the SESAR JU programme) and experience from operations are important inputs to the development of formal specifications, standards and regulatory framework material (such as this document).