From a strategic perspective, one objective of the Navigation Domain is to validate different navigation applications and provide support to States during implementation. These applications are described in the Navigation Strategy and all have been demonstrated to be technically viable through R&D, undertaken in EUROCONTROL and the research centres of member States during the period 1975 to 1999. Those applications which provide the greatest net present value are progressed though validation into operation.
A co-ordinated introduction of such applications across ECAC will increase operational efficiency and airspace capacity, and will reduce the environmental impact. The goal is to develop a detailed implementation programme that provides a coherent progression of applications. This will enable users to gain short term benefits from readily available navigation capabilities whilst simultaneously developing the capability to transition towards more sophisticated applications at a later date.
In this manner, early benefits were realized, in April 1998, by mandating the carriage of B-RNAV equipment for en-route operations in ECAC airspace. Subsequently, the P-RNAV application has been defined and validated at an ECAC-level, and is now being implemented by a number of member States, with the continuing support of EUROCONTROL. RNAV approach applications using GNSS together, in some cases, with RNP capabilities, are also close to fruition. The challenge now is to extend the application of existing RNAV capabilities to all phases of flight, as equipage permits, and thereby derive additional benefits through the application of 3D RNAV (providing profile guidance) and ultimately 4D RNAV (giving time guidance). The detailed functional and operational characteristics of the on board system and navigation infrastructure required to enable the benefits to be realized will be further defined as experience is gained.
In the short term, the operational concepts are based on exploiting existing capabilities and infrastructures, and are focused primarily in terminal airspace. These are low cost to operators and represent a low risk, since the aim is to maximise the benefits of existing aircraft equipage. As a result the expected benefits may be limited by the capability of the existing systems to operate efficiently with the existing ATM systems. The benefits may also be limited by the ability of ATM systems to manage this mix of traffic capabilities. In this context, the P-RNAV Integrated Initiative has sought to standardize the application of RNAV on SIDs and STARs throughout ECAC. Similarly, encouraging the introduction of RNAV (GNSS) Approaches allows users to take advantage of existing airborne capabilities at no additional cost.
In the medium term, operational concepts are based on more advanced navigation capabilities that can be exploited efficiently through the provision of ATM tools such as arrival and departure managers and route conformance monitors. These will enable efficient operations in high density environments whilst maintaining or even increasing system capacity. In order to maximise benefits in the longer term, it may be necessary to mandate equipage to support uniform ATC procedures. This phase is low/medium cost and low risk since mandates will only occur once the need and the advantages have been demonstrated. Additional functionality such as fixed radius turns in terminal airspace, fixed radius transitions in the en-route, vertical navigation, and RNP holding may be required. The EUROCONTROL TMA 2010 project, which addresses controller tools in support of RNAV operations, will be crucial to the successful introduction of these navigation applications.
In the long term, the ATM operational concept is expected to be based on 4D navigation capabilities and an optimised navigation infrastructure. This represents a major change in RNAV functionality and will also significantly impact the design of the ATM interface and ATM support tools. It will inevitably also affect the airspace design. Operators may have to install new airborne functionalities and service providers will have to develop an appropriate ground infrastructure (more advanced planning and monitoring tools, interface to data link etc). The business case for such applications will need to clearly demonstrate the benefits and confirm that the proposed technical enhancements are necessary, and the most cost effective solution, for the realisation of these benefits.
