INTRODUCTION
The PBN concept specifies aircraft RNAV system performance requirements in terms of accuracy, integrity, availability, continuity and functionality needed for the proposed operations in the context of a particular Airspace Concept. The PBN concept represents a shift from sensor-based to performance-based navigation. Performance requirements are identified in navigation specifications, which also identify the choice of navigation sensors and equipment that may be used to meet the performance requirements. These navigation specifications are defined at a sufficient level of detail to facilitate global harmonization by providing specific implementation guidance for States and operators.
Under PBN, generic navigation requirements are defined based on the operational requirements. Operators are then able to evaluate options in respect of available technologies and navigation services that could allow these requirements to be met. The chosen solution would be the most cost effective for the operator, rather than a solution being imposed as part of the operational requirements. Technologies can evolve over time without requiring the operation itself to be revisited, as long as the requisite performance is provided by the RNAV system. As part of the future work of the ICAO, it is anticipated that other means for meeting the requirements of the Navigation Specifications will be evaluated and may be included in the applicable Navigation Specifications, as appropriate.
PBN offers a number of advantages over the sensor-specific method of developing airspace and obstacle clearance criteria:
- Reduces need to maintain sensor-specific routes and procedures, and their associated costs.
- Avoids need for development of sensor-specific operations with each new evolution of navigation systems, which would be cost-prohibitive.
- Allows more efficient use of airspace (route placement, fuel efficiency, noise abatement).
- Clarifies the way in which RNAV systems are used.
- Facilitates the operational approval process for operators by providing a limited set of navigation specifications intended for global use.
Within an Airspace Concept, PBN requirements will be affected by the communication, surveillance and ATM environment, as well as the Navaid infrastructure and the functional and operational capabilities needed to meet the ATM application. PBN performance requirements will also depend on what reversionary, non-RNAV means of navigation are available and hence what degree or redundancy is required to ensure an adequate continuity of function.
The development of the Performance-Based Navigation Concept recognizes that advanced aircraft RNAV systems are achieving a predictable level of navigation performance accuracy which, together with an appropriate level of functionality, allows a more efficient use of available airspace. It also takes account of the fact that RNAV systems have developed over a 40-year period and as a result there are a large variety of implementations. PBN primarily identifies navigation requirements irrespective of the means by which these are met.
The ICAO PBN Programme Team |
David Van Ness |
Erwin Lassooij |
Nancy Berardinelli |
Implementation and Resource Development Coordinator |
Programme Manager |
Administrative Coordinator |
Air Traffic Management Section |
Air Navigation Bureau |
Telephone: +1 514 954-8219, extension 7024 |
Fax: +1 514 954-6759 |
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