ANNEX B. ASSESSMENT OF THE NEED FOR A PBN IR AND PROPOSED OPTIONS FOR THE REGULATORY APPROACH

Transcription

1 ANNEX B. ASSESSMENT OF THE NEED FOR A PBN IR AND PROPOSED OPTIONS FOR THE REGULATORY APPROACH B.1 Introduction The general objective of the SES PBN IR as described in the EC mandate to EUROCONTROL is to ensure that navigation capability improvements are introduced in ECAC airspace in an optimal and coherent way through defined navigation performance requirements and functionalities taking due account of the European network performance targets and other operational, environmental and implementation factors, whilst ensuring global interoperability. B.1.1 Purpose and Scope This annex first assesses the need for the development of the PBN IR and, from this analysis, describes regulatory options in the framework of the EC Mandate to EUROCONTROL for the development of a draft interoperability implementing rule on PBN. The content of this annex constitutes one of the input streams to the preliminary impact assessment activities as part of the development of the draft Regulatory Approach Document which is now being submitted for formal written consultation with Stakeholders. B.1.2 Organisation of the document This annex is organised as follows: Section B.1 provides an introduction to the document; Section B.2 assesses of the need for a PBN IR; Section B.3 describes the proposed regulatory approach options for the development of the draft PBN IR that will be subjected to preliminary regulatory impact assessment; Page B-1

2 B.2 Assessment of the Need for a PBN IR B.2.1 Assessment Methodology A three-stepped approach has been developed to analyse the factors giving rise to the need for regulation: 1. Identification of key drivers of navigation performance requirements (see section B.2.2) Global and regional strategic objectives; Current & future applicable targets to ATM in Europe; Other external pressures on European ATM; New concepts of operations under development. 2. Navigation requirements assessment Assess if and how the current navigation requirements could meet the elements identified above (see section B.2.3). 3. The need for regulation Derive the problem giving rise to the need for regulation (see section B.2.4) 4. Specific objectives of the draft PBN IR (see section B.2.5) B.2.2 Identification of key drivers of navigation performance requirements B Global and regional strategic objectives Relevant international strategic objectives need to be considered when establishing harmonised navigation requirements for Europe. The following specific ICAO strategies and resolutions aiming primarily at increasing safety and ensuring global interoperability apply to PBN: The Global ATM Operational Concept 1, endorsed by ICAO 11th Air Navigation Conference and published as ICAO Doc 9854, provides the framework for the development of all regional ATM concepts; AN-Conf/11 also endorsed a number of technical recommendations 2 affecting navigation, including the harmonization of air navigation systems between regions, frequency planning, the transition to satellite based air navigation, curved RNAV procedures, and the use of multiple GNSS signals and the rapid implementation of approaches with vertical guidance; ICAO Assembly Resolution A37-11 urges Member States to implement RNAV and RNP operations for en-route and terminal areas as well as RNP Approach procedures; according to established timelines. The agreed approach is to deploy APVs at all instrument runway ends either as the primary approach or as a back-up to precision approach by 2016; however, for certain aerodromes or aircraft functionalities this may just be a LNAV only procedure. 1 ICAO Global ATM Concept, Doc ICAO Report of the 11 th Air Navigation Conference (AN-Conf/11), October 2003 Page B-2

3 Following ICAO 37 th General Assembly, ICAO launched the ASBU initiative which intends to apply key capabilities and performance improvements drawn from near-term regional implementation plans, across other regional and local environments with the same level of performance and associated benefits on a global scale. Implementing the PBN concept has a central place in the initiative notably on the following operational improvements: Improved Operations through Enhanced En-Route Trajectories Improved Airport Accessibility Improved Flexibility and Efficiency in Descent Profiles Improved Flexibility and Efficiency in Departure Profile Additionally, the FAA has published a document proposing provision of navigation services for the next generation air transportation system (NextGen) in view of transition to PBN 3. Consideration of other regional plans might help ensure further interoperability as well as ensure more cost-efficiency solutions notably for operators. The draft PBN IR shall be developed according to these high level global strategic objectives to ensure full interoperability. B Current & future applicable targets to ATM in Europe B Current and future SES performance targets Based on the work previously performed by EUROCONTROL through its PRC, the European Commission adopted Regulation 691/2010 laying down a performance scheme for air navigation services and network functions in July This marked the start of the implementation of the performance scheme, and in particular preparation for the first reference period (RP1) that runs for three years from 2012 to The Performance Review Body (PRB) (EUROCONTROL) prepared EU-wide performance targets proposals 4, in collaboration with EASA, for environment, capacity and cost-efficiency, ensuring consistency with the overriding safety objectives. These key indicators and associated targets for RP1 are: Average horizontal en-route flight-efficiency (environment key performance area): a reduction of 0.75 percentage points in the EU-wide Key Performance Indicator (KPI) (compared to 2009 baseline); Minutes of en-route Air Traffic Flow Management (ATFM) delay per flight (capacity key performance area) : 0.5 min/flight; Average EU-wide determined unit rate for en-route ANS (cost-efficiency performance area) 57,88 Euros in 2012, 55,87 Euros in 2013, and 53,92 Euros for Finally, and although its influence on the network performance is less than that of the horizontal en-route flight efficiency 5 vertical flight profile efficiency was also recommended to 3 Federal Register/Vol.76, N. 241/Thursday, December /Proposed Rules 4 SES II Performance Scheme Proposed EU-wide Performance Targets for the period th September Vertical Flight Efficiency PRU Technical Note March 2008 Page B-3

4 be monitored by the PRB in view of defining associated KPI setting new additional targets in the second reference period. The PRB report document 6 sets out evidence that current capacity enhancement plans are consistent with achieving an average delay per flight of 0.7 minute. As the EU-wide capacity target for 2014 is set at 0.5 minutes of en-route ATFM delay per flight, all causes included, careful planning and implementation by the ANSPs and the Network manager is already required to ensure this target can be achieved without undue impact on costefficiency. However the ultimate capacity target reaching the economic optimum for delay is approximately 0.35 minutes per flight and was recommended to be reached as soon as practicable. This would require further ATM improvements in particular for en-route operations. The SESAR programme has introduced even more challenging performance targets for the timeframe, based on operational improvements supported by new concepts such as Trajectory Based Operations (TBO) and new technologies such as GNSS. Enable a three-fold increase in capacity over 2006 levels which will also reduces delays, both on the ground and in the air; Improve the safety performance by a factor of 10; Enable a 10% reduction in the environmental effects per flight and; Reduce ATM unit costs to the airspace by at least 50% less. The SESAR programme aims to develop new concepts and technologies to provide medium and long term solutions to meet the most challenging ATM targets set out above. Commission Decision 2011/121/EU 7 include a recommendation on setting the future EUwide performance targets considering these SESAR performance targets. B Other external pressures on European ATM B Traffic forecast implications In the medium-term ( ) the EUROCONTROL Statistics and Forecasts Service (STATFOR) report 8 indicates stable traffic growth in Europe of between 1.1% per annum (low growth scenario) and 3.0% per annum (high growth scenario) with a baseline scenario estimate of 2.1% per annum. However, growth is likely to be higher in most of the states in Eastern Europe. In the long-term 9 ( ) the forecast confirms this trend, as there will be 1.8 times more Instruments Flight Rules (IFR) movements in 2030 than in The growth will average 2.8% per annum in the most-likely scenario. Furthermore, the STATFOR long-term forecast report emphasises that even with capacity restrictions airports will grow. In 2030, there will be between 13 and 34 new airports as big as 6 SES II Performance Scheme Proposed EU-wide Performance Targets for the period th September COMMISSION DECISION of 21 February 2011, setting the European Union-wide performance targets and alert thresholds for the provision of air navigation services for the years 2012 to 2014, (Text with European Economic Area (EEA) relevance) (2011/121/EU), OJ, L48/16 dated EUROCONTROL Medium-Term Forecast February 2012: Flight Movements , 28/02/ EUROCONTROL Long-Term Forecast Flight Movements /12/2010 Page B-4

5 the existing top seven. Some faster growing East-European airports will join the top 25. European hubs will be faced with competition from hubs outside Europe, primarily in the Middle-East. Therefore the future air traffic will be limited by airport capacity. It is expected that 5%-19% of the demand will not be accommodated in In view of the forecast increase of traffic and the limitation on airport developments, meeting the future SES ATM performance targets will be extremely challenging. Thus, to improve airport operations efficiency new concepts of operations and technologies are required. B Environmental requirements Pressure on emission reduction has increased since 1 st January 2012 with the inclusion of aviation within the Emissions Trading Scheme (ETS) 10. In order to reduce CO 2 emissions, it is necessary to improve both horizontal and vertical efficiency of flights in both en-route and TMA airspace in terms of time of flight and optimised profiles. One of the major challenges for improving efficiency will be the improvement of aviation s environmental performance in the face of future traffic growth. Aircraft noise restrictions constrain ATM at the airport level. A well balanced and forwardlooking strategy is required for the Airport Operator, ANSP, Competent Authorities (such as aviation regulators) and the local land use planning authorities to reduce noise exposure and the number of inhabitants affected by noise, while optimising the use of airport capacity. To reduce both emissions and noise there is therefore a need to improve lateral and vertical flight efficiency: a) with more stringent track keeping performances; b) with improved adherence to trajectory; c) by enabling complex Noise Preferential Routes (NPRs); d) and with improved flight predictability. B Military requirements Predicted military airspace requirements envisage a need for larger reserved airspace volumes to accommodate the evolution of military missions associated with national defence and security responsibilities. B New concepts of operations under development B Airspace evolution in Functional Airspace Blocks (FAB) The 2015 Airspace Concept and Strategy anticipate that airspace changes up to 2015 will provide the following benefits: Safety (by maintaining sector loads at reasonable level through optimised sector configurations, de-conflicting ATS routes, etc.); Capacity (through the maximum exploitation of airspace resources, not constrained by national boundaries, the creation of optimised routes, by reducing conflicts through redesign of airspace, optimised sector design, optimum sector configurations, etc.); 10 DIRECTIVE 2009/29/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 23 April 2009 amending Directive 2003/87/EC so as to improve and extend the greenhouse gas emission allowance trading scheme of the Community. Page B-5

6 REGULATORY APPROACH Flight efficiency (by the use of optimised trajectories in specific areas or implementation of more direct routes, for example); Environmental impact (reduced through measures aiming at improving flight efficiency). There is not a single European ATM solution which meets the capacity challenge. In certain airspace, the density of traffic will require a fixed route network which, subject to an appropriate safety case, could be placed closer together than today s operation. However, there are other parts of the European network which do not have the density of traffic necessitating such a route network and a free route environment allowing user preferred routing would provide the efficiency needed without limiting capacity. Two types of airspace changes, derived from this Airspace Concept, are under development and implementation in Europe: closely spaced fixed route network and free route concept. Within some of the FABs a need has been identified for more closely spaced routes partially to accommodate the longer term requirement 11 for capacity increase but also to enable multiple routes in the reduced airspace between reserved areas, especially those where military training occurs. Closely spaced routes criteria shall apply not only to straight segments but also to turns. It is also expected that there will be an increasing use of free route operations 12 in European airspace, particularly in low traffic density areas, which will still require area navigation system performance to navigate from entry point to exit point or outside the free route sectors. B Trajectory Based Operations (TBO) TBO requires that aircraft trajectories be planned in four dimensions (3 spatial and 1 time = 4D) with a very high precision, and then executed with similar precision. SESAR Concept of Operations for example specifies navigation accuracy improving to +/- 10 seconds longitudinally. Precise management of trajectories significantly reduces the volume of airspace needed for a given flight and this translates into more flights per unit of airspace (increased capacity) and a reduced need for ATC intervention. Furthermore, even when an intervention becomes inevitable, this can result in deviation of shorter length and duration than is the case in the current system. TBO also requires the introduction of powerful and effective queue management and separation assistance tools. However, presently, TBO concept is still under development. Furthermore, changes required on the existing equipment affects a large number of airborne systems and require new ground tools, to such an extent that a direct transition towards full 4D can not be envisaged. As a first step the RTA capability already installed in aircraft should provide early benefits, if used. B.2.3 Navigation requirements assessment This section first provides background information on navigation requirements evolution that led to ICAO PBN concept. It then assesses if and to what extent, for all phases of flight, the 11 Studies have shown the need for Fixed Radius Turn (FRT) capability, integrity monitoring and alerting functionality (RNP) and lateral navigation accuracy performance of 1NM. 12 Free Route Airspace is explained in the Operational Environment Section of Annex A Operational Services and Environment Definition (OSED) Page B-6

7 current navigation requirements are sufficient to meet the strategic objectives, the European targets and future concepts of operations identified in section B.2.2. B Development of Performance Based Navigation In the 1970s, commercial aircraft started being fitted with first generation digital avionics and computers. This capability allowed the pilots to programme the computer to fly to a coordinate rather than home to a ground based navigation aid; this ability for the aircraft to fly on any desired flight path is referred to as area navigation. In the early 1990s, ICAO introduced the Required Navigation Performance Concept (RNPC) based on area navigation and industry identified a range of functional capabilities that the aircraft avionics could have in the Minimum Aviation System Performance Standards: Required Navigation Performance for Area Navigation (RTCA DO-236). As congestion at some points of the ECAC airspace was already occurring in 1990, European area navigation applications were developed to overcome the problem of point-to-point navigation based on the location of the ground navigation aids. B-RNAV requiring a lateral track accuracy of +/- 5NM 95% of the flight time was developed for en-route operations and had a limited set of functional requirements based on the early first generation technology. B-RNAV was never considered adequate for aircraft operations near to terrain as the navigational accuracy and the level of aircraft functionality was not good enough for safe operation. Therefore, a P-RNAV application, requiring increased functionality and a lateral performance accuracy of +/-1NM 95% of the flight time, was developed. Both these area navigation applications were European specific and in other ICAO regions different navigation applications were being developed demanding different functional requirements and navigational performance. ICAO realised that the global proliferation of differing navigation applications would lead to confusion for the airspace users and create safety issues. Therefore, ICAO developed the PBN concept which set out to clarify the terms RNAV and RNP and created a limited set of global navigation specifications to ensure common understanding of the requirements to operate in specific airspace. The PBN manual (ICAO DOC 9613 Edition 4) states that for an aircraft to meet a RNP specification the avionics must provide on-board performance monitoring and alerting ; RNAV navigational specifications do not require this functionality. The navigation performance accuracy, together with functional requirements and the navigation sensors needed for a specific operation in a particular phase of flight are defined within the appropriate RNAV or RNP specification. In terms of the European navigation applications B- RNAV is exactly the same as RNAV5 navigation specification and P-RNAV is similar to the RNAV 1 navigation specification and requires the same lateral accuracy performance but is not exactly the same. B En route Operations Is the present harmonised RNAV 5 13 navigation specification which applies to en-route airspace adequate to support the planned reduced route spacing operations envisaged by some of the FABs (see section B.2.2.4)? A higher harmonised standard of navigation performance is required which would include: Lateral navigation accuracy performance To conduct closely spaced route operations, in the level of capacity defined by the SES performance targets, safety studies 14 have identified a requirement for a lateral 13 RNAV5 (previously B-RNAV) was introduced in 1998 and is currently the only mandated navigation requirement in the European Civil Aviation Conference (ECAC) area. This requirement applies above Flight Level (FL) 95 in most states. 14 Ref to be added Page B-7

8 REGULATORY APPROACH navigation accuracy performance of 1NM 95% of the time. Therefore RNAV 5 navigation specification with its 5NM accuracy performance is not suitable for such a route network. Predictable and repeatable turn performance Current lack of common turn transition requirement results in large performance variations when flying turns. This necessitates maintaining a large separation between route centrelines for safety purposes and this severely limits the ability to increase airspace capacity. Considering the future SES capacity and environmental targets set out by EC (see section B ) this functionality should be required. RNAV 5 does not require turn transitions and is therefore not suitable. Integrity monitoring and alerting functionality (RNP) Given the future SES capacity targets an on-board performance monitoring and alerting functionality will be required when conducting closely spaced route operations to meet an acceptable level of safety. RNAV 5 navigation specification does not include the RNP functionality and therefore is not suitable. In en-route airspace the current navigation requirements are not sufficient: there is a need to maintain harmonised navigation performances but with enhanced navigation specification (more stringent accuracy, turn transition and on-board performance monitoring and alerting). B Terminal Airspace Operations Are the current TMA navigation requirements adequate to support the future proposed concept of operations in TMA (they include in particular closely spaced parallel SID & STARs as well as environmental routes and TBO with RTA)? A. The P-RNAV specification was developed and published in It is designed to provide the means of operating RNAV in terminal airspace that was needed by many ANSPs/airports to link the runway to the en-route B-RNAV routes. As no ECAC-wide requirement for the carriage of P-RNAV equipment exists, as operators considered mandating P-RNAV not to be cost efficient, a variety of RNAV solutions have been developed by States to design SIDs and STARs. These solutions do not correspond to the navigation requirements published in any existing Temporary Guidance Leaflets (TGL) / Acceptable Means of Compliance (AMC) or FAA order, but are extension of B-RNAV whose application is not appropriate to terminal area operations. The result is a proliferation of a variety of extended B-RNAV solutions, with no clearly defined requirements for on-board systems or naming convention, and a consequent confusion of requirements across Europe. This situation leads to uncertainty about an aircraft s ability to operate safely on a specific terminal procedure and consequently presents a safety risk. Therefore to provide more clarity to airspace users and improve the level of safety a harmonised PBN solution is needed for operations in the terminal airspace. Furthermore as for en-route RNP capability, accuracy of not more than 1NM and repeatable turn performances would be required to meet the closely spaced concept when applied in TMA. B. CCOs and CDOs are flight techniques whereby the pilot will climb or descend continuously, to the greatest extent possible, by employing optimum thrust settings, ideally from top of descent for arrivals and to top of climb for departures. By flying at optimum thrust settings and reducing the amount of levelling off, the amount of fuel burnt (and CO 2 emitted) will both be reduced, potentially with a reduction in aircraft noise. Although these techniques can be undertaken without coupled guidance, the use of Page B-8

9 vertical coupled guidance provided by the area navigation system reduces significantly pilot workload. Furthermore, for the SIDs and STARs that have been published with specific vertical constraints, pilot workload can be reduced and efficiency of the vertical profile between these constraints may be optimised by the area navigation system. Vertical navigation and repeatable turn performance would be required to improve the above environmental requirements. C. More efficient airport operations are required in the near future according to the European forecasted traffic report 15. One key issue regarding airport efficiency of large airports with parallel runways is the operational limitation imposed on parallel operations (departures or approaches) due to the lack of stringent RNP lateral guidance performances requirements. Stringent standardized lateral performances such as RNP 0.3 would be required to enhance airport operations notably those with parallel operations. D. To support the Trajectory Based Operations concept a time of arrival control capability is needed. This would require for an optimisation of trajectory stringent timing performance. This could be envisaged through the use of the RTA onboard functionality. Current navigation requirements in European en-route airspace and terminal control airspace are not suitable. B Final Approach Operations Are the current final approach navigation requirements adequate to meet the need for improved airport efficiency as well as maintaining safety level with increased traffic level? Continuation of conventional NPA will not bring the CFIT reduction expected from an approach which provides the pilot with vertical guidance together with improved situational awareness. Furthermore, access to aerodromes which do not have a precision approach landing system is restricted to the conventional NPAs minima. Provision of a lateral and vertical approach path with reduced protection areas should allow for lower decision heights and allow suitably certified and operationally approved airspace users greater access to these types of airfields. More stringent navigation requirements are required for improving airport operation through the provision of vertical guidance. B Navigation aid (NAVAID) infrastructure and equipage The current European route structure and procedures has been built as a compromise between operational need and the feasibility to install the required navigation aids in the corresponding locations. Even much of the B-RNAV route structure in upper airspace is still aligned with underlying conventional navigation facilities. PBN opens the door to optimize both the route structure and procedures fully in line with the operational need, completely independent of the physical location of terrestrial infrastructure. Satellite or space-based infrastructure is a key enabler for this flexibility. This serves both the needs in constrained (complex / high density) airspace, as well as in low density areas (flight efficiency, avoidance of ground facility installations in remote airspace with a scarce infrastructure). Despite these significant benefits, it remains important to retain a reversionary capability to mitigate the risk of GNSS service outages. While the current conventional infrastructure, 15 Reference to be added here Page B-9

10 coupled with the multi-sensor capabilities of most RNAV-capable aircraft already provides a useful service, this cannot support RNP operations for many airspace users. Consequently, the current network of facilities enabling VOR/DME and DME/DME navigation will serve a back-up role. The details of this evolution will still need to be further clarified; however, the current terrestrial infrastructure will need to be aligned with the PBN IR as follows: In areas with a mature (dense) navigation infrastructure, redundancy can be removed through rationalisation. This will occur at the end of equipment lifecycles, primarily for NDB and VOR. This enables a significant rationalization of facilities, while retaining those facilities necessary to serve in the reversion network. Overall, optimise the terrestrial navigation infrastructure to serve a back-up role to GNSS (RNP) PBN operations. This optimisation may require some facilities to be relocated and in some cases even the installation of new systems. The principle of this evolution will be that apart from rationalisation, only minor modifications to the terrestrial infrastructure network will be undertaken, as it is not justified to expend resources for what will remain a lower level of service. In cases where terrestrial navigation reversion coverage is considered insufficient, other mitigation means will be considered (surveillance coverage, procedural operations, etc.) The terrestrial infrastructure evolution described here will ensure a cost-effective evolution to a facility network that will maintain safety while being as spectrally efficient as possible. This solution ensures complementarity to GNSS (which enables the PBN related benefits) and capitalises on the existing fleet RNAV capabilities. B.2.4 The need for regulation B Summary of operational problems The current route network structure, including final approach procedures, suffers from problems of airport and flight inefficiency, delays, noise emissions and CFIT. Various SES strategic objectives and accompanying targets have now been put in place to ameliorate these problems and, as indicated in the previous sections, the application of PBN can make a major contribution towards meeting these objectives and targets. However, there are limits to which the objectives can be met if PBN were to be implemented by means of progressive evolution. These are described below. B Mixed navigation performances constraints Without an EU regulation, it is expected that pressure from high-end airspace users to gain benefits from their advanced capabilities, will increase the demand for mixed mode operations to accommodate optimised operations. Consequently, a mixed navigation performance mode would need to be accommodated in Europe. Real-Time route spacing simulations undertaken by EUROCONTROL have consistently demonstrated, over a 15 year period, that accommodating mixed navigation performance capability within an airspace leads to a reduction in capacity of the network due to increase in ATC workload. Furthermore, the necessity to publish with a separate designator - define and load in the navigation database, different routes for different levels of navigation performance (as well as attendant waypoints) cannot necessarily be accommodated by navigation system databases having limited storage. A plethora of routes to cater for different performance also increases the probability of human error where, for example, ATC allocates the wrong route to an aircraft or the air crew selects the wrong route from the database. The complexity of the airspace design is also rendered less efficient by the need to accommodate routes and procedures for different levels of performance. The net Page B-10

11 effect of this accommodation of different performance is that route spacing cannot be optimised because the spacing has always to be set at the largest difference, catering for the lowest level of performance. This means that if an RNAV 5 and RNAV 1 route are designed as parallel routes, the spacing between the routes is that used as if they were two RNAV 5 routes. In fact, this mixed navigation mode could result in a delay in achieving benefits of years from the first carriage of the equipment with the required capability. This is certainly not optimal in the European congested airspace environment given the SES performance targets to be achieved in the near future. Furthermore, optimisation of the NAVAID infrastructure will not be fully realised, further limiting the expected benefits on infrastructure maintenance and installation costs. Finally, it is expected that a SES PBN IR through the civil/military coordination Essential Requirement would help maximise the number of State aircraft capable of demonstrating compliance to the PBN requirements. This will minimise the need for exemptions and consequently reduce the risk of creating another level of mixed navigation mode operation. B Implementation timescales constraints Increasing the timeframe between the publication of an implementing rule and its implementation date will reduce implementation costs as more new production aircraft can be fitted with required equipment. However delays in implementation delays the achievements of benefits. Moreover, alignment of implementation timescales across different EC mandates is essential to limit operator s costs. Specific problems faced by the military include the high number of aircraft, multiple types and variants, limited defence budgets, lengthily procurement processes and technical difficulties in fitting additional equipment in already very complex aircraft. There may, therefore be a need for transition arrangements to take account of the procurement and technical constraints that military organisations face when confronted with ATM improvements. Despite the ICAO Assembly Resolution A37-11 there is still a slow progress of implementation of APVs using GNSS for lateral positioning and either barometric vertical navigation or SBAS for the vertical element. An implementing rule will help expedite the resolution. Without optimising the implementation timeframe through a PBN implementing rule, the most cost-effective implementation solution for the aviation community would be very difficult to achieve. B Conclusion It is therefore concluded that, in accordance with ICAO strategic objectives, PBN shall be introduced in Europe as a key enabler to the SES performance targets. Moreover, it has been shown that a single European sky implementing rule would provide the framework to reduce mixed navigation operations and optimise deployment of PBN routes and procedures across Europe in a timely and efficient manner whilst ensuring a balanced approach supported by appropriate means of compliance. B.2.5 Specific Objectives of the draft implementing rule From the above assessment the following specific objectives for the development of the draft PBN IR have been derived: Page B-11

12 Ensure optimal use of airspace through the improved design of the ATS route structure based on common navigation performance requirements and functionalities in en-route airspace by 2020; Increase access to airports through the introduction of arrival and departure routes and approach procedures based on common navigation performance requirements and functionalities in terminal airspace by 2020; Reduce CFIT by the full deployment of approaches with vertical guidance; Maximise the use of RNAV approaches in terrain rich environment as well as in noise sensitive areas across Europe; Maximise horizontal and vertical flight efficiency across Europe; Enable decommissioning or non replacement of conventional navigation aids; Introduce new requirements in a manner which minimises operators certification and approval costs; Facilitate the transition to the SESAR TBO concept through the introduction of functional requirements and procedures by 2025; Ensure harmonised PBN operations in en-route airspace and in TMA. The draft PBN IR will be developed with dates to be confirmed based on the outcome of the impact assessment and stakeholder consultation activities. Page B-12

13 B.3 Options for the development of the draft PBN Implementing rule B.3.1 Selection of PBN regulatory options B PBN IR options: a phased approach To support the resolution of the problem giving rise to regulation, three regulatory options have been developed. These options comprise a number of navigation functionalities, navigation performance and infrastructure requirements. Each option covers all phases of flight: En-route, Terminal Airspace and Final Approach. The options consider the requirements specified in Section 5.1 of the EC Mandate, notably, the navigation performance requirements and the functionalities to be used in en-route and terminal airspace operations. In order to cope with the failure modes, e.g.: RNP system failure and a loss of GNSS, and the business continuity requirement for each option, two levels of operational continuity are considered in terms of NAVAID infrastructure and airborne equipment (see Section B.3.4 below for more details). For each option specific requirements associated with the accommodation of State aircraft have been analysed. This entails the consideration of dates aligned with military procurement cycles, taking due account of new production transport type State aircraft (considering the set of navigation functionalities as for civil aircraft), and opportunity for performance-based equivalent compliance for non-transport type State aircraft and transitional accommodation of lower-capability State aircraft. B.3.2 General Considerations B Navigation System Requirements To ensure more complete use of available airspace than with conventional navigation an area navigation system is required. Additionally to ensure appropriate on-board performance of the navigation an RNP alerting system is needed. Other navigation functionalities are required for operational purposes as explained in section B.2.3 and further detailed in Annex A: OSED. Furthermore, the performance requirements in terms of the most stringent navigation accuracy of this area navigation system for terminal and approach operations can only be achieved by the use of GNSS. As a result, GNSS carriage will be required for all options. Finally, to ensure an acceptable level of safety the area navigation system robustness to failures notably to the loss of GNSS Signal in Space (SIS) and RNP system failure needs to be sufficient. Even with multi-constellation GNSS, satellite systems remain susceptible to interference through natural events or deliberate actions. Therefore a reversionary capability is necessary, which may be provided by a combination of means such as VOR/DME, DME/DME, radar surveillance, or onboard inertial augmentation capability. Area Navigation currently requires only one RNAV system as the navigation continuity requirement can be met by the VOR or NDB reversionary capability. If VORs and/or NDBs are to be decommissioned due, notably but not only, to the advent of multi-constellation GNSS, a dual RNAV system may be required to ensure the airborne continuity requirement. Page B-13

14 The operational continuity levels addressing the loss of GNSS SIS and RNP system failure which will be assessed in the PBN IR impact assessment are presented in section B.3.4 below. B En-route Operations Although ICAO provides no definition of en-route or terminal airspace, the regulatory options in the draft RAD use these expressions to describe different operations and to reflect the need for different navigation performance requirements. En-route airspace expands from the minimum ATS fixed route altitude, e.g. B-RNAV is mandated above FL95 up to the maximum certified flight level. However, this airspace can be spilt into two parts above FL195 and below FL195. Whilst this nominal level suggests a difference in operations above/below it, it must be noted that this division is more one of convenience (associated with current area navigation systems) rather than one of an absolute nature. B Operations above FL195 In the European airspace above FL195 ATS routes predominate with relatively few SIDs and STARs. Therefore in this document airspace above FL195 is intended to denote en-route airspace. The en-route airspace structure ideally requires a uniform navigation capability for maximum efficiency of service provision to be achieved. In this part of the en-route airspace it has been demonstrated that the need for 7NM route spacing for both straight and turning routes results in the need for the area navigation system operating above FL195 to enable aircraft to execute FRT and meet RNP1 performance standards in support to the future network performance requirements. B Operations below FL195 In the European airspace below FL195 SIDs and STARs and IFR predominate with relatively few other types of ATS routes. Therefore in this document airspace below FL195 is intended to denote en-route and terminal airspace. Air traffic management in this airspace is more complex than above FL195, as a result of the more varied mix of aircraft performance, i.e. commercial air transport, military aircraft and general aviation and extensive manoeuvring of aircraft in the vertical and horizontal plane. For the en-route portion of the airspace below FL195, the ATS route network will not require FRT between route segments. Therefore, where aircraft operations are limited to below FL195, the carriage of an area navigation system with FRT capability will not be required in any option. B Terminal Airspace Operations (Operations below FL195 to Final Approach Fix (FAF)) Another characteristic of the airspace below FL195 is the need for routeing systems along which to channel arrival/departure flows from/to numerous airports. Given the geographic characteristics of Europe, the location of the core area and the large terminal airspace systems 16 within that core area, there is a continuing need for a complex system of published parallel and crossing ATS routes (mostly SIDs/STARs/Instrument Flight Procedures) to accommodate the interaction between arrival and departure flows to/from airports, between airports, between terminal areas and between terminal airspace systems. Due to the number and complexity of operations in terminal airspace, an area navigation system that is capable of optimising aircraft performance when operating on SIDs/STARs or Instrument Flight Procedures is required. 16 These areas can extend above FL195. In the USA these are referred to these as metroplexes Page B-14

15 By optimising aircraft performance in terms of distance flown together with optimised vertical and horizontal profiles, the potential environmental impacts of terminal operations can be reduced. B Final Approach Operations There are currently three alternatives for Final Approach: NPAs, APVs and PAs. At present many runways still have only NPAs because the cost of providing a PA capability is too high on a runway with relatively few operations. Even where a runway has a PA to support operations at one end of the runway, for occasions where the wind prevents use of that landing system, the approach to the other end of the runway is often an NPA. Conventional NPA procedures due to their limited performances have usually significantly higher minima than NPA procedures based on GNSS. NPAs based on GNSS and APVs also based on GNSS, named as RNP approaches, present lower minima than conventional NPA procedures. Therefore RNP approaches improve access to runways. A precision approach provides vertical guidance. Vertical guidance has been identified as a key factor for limiting CFIT. APVs are new types of approach procedures defined also with vertical guidance but with less stringent performance requirements than precision approach procedures. They are gradually being implemented with the aim of improving safety by reducing notably CFIT at runways where precision approaches would not be available. The provision of one or more of these procedures at a given runway depends largely on the local airport operator and regular users. B.3.3 Proposed Regulatory Approach Options Four possible scenarios have been developed and assessed for their potential impact a Do-Nothing scenario and three other scenarios containing regulatory measures. These are identified as regulatory approach options and are detailed in sections B through B Each option addresses all phases of flight - En-route, Terminal Airspace and Final Approach. For each option, and in accordance with the phase of flight considered, a number of navigation functionalities, navigation performance and infrastructure requirements have been proposed that would support resolving the problem analysed and defined in section B.2.2 to B.2.4 above. As the Do-Nothing scenario is not considered appropriate to respond to the future needs of the EATMN, it is not considered as an option. The other three scenarios have been retained and assessed as possible options for the regulatory approach. In parallel to the options and in order to cope with the failure modes (e.g.: RNP system failure and loss of GNSS) and the business continuity requirement, two levels of operational continuity are considered in terms of NAVAIDS infrastructure and airborne equipment as detailed in section B.3.4. B Do-Nothing scenario The Do Nothing scenario describes the case where no new 17 PBN regulatory measure is to be applied in Europe. This reference scenario comprises an estimate, built on best expert judgement, of how navigation capabilities and PBN procedures will evolve from today to 2025 and beyond. 17 B-RNAV is a PBN regulatory measure Page B-15

16 It has been used as a reference scenario when assessing the benefits of regulatory measures considered under the regulatory options. B En-route Operations (above FL195) B-RNAV is the only mandated navigation performance requirement in ECAC and this requirement applies above FL95 in most states. Despite the fact that the ECAC fleet operating above FL195 is primarily capable to more stringent performance standards, in this option, the existing fixed ATS route network spacing on straight segments, is predicated on 5NM accuracy 95% of the time, without monitoring and alerting functionality and without any turn performance requirements, will remain indefinitely. In this scenario, it is therefore expected that the current aircraft navigation capabilities would be largely under-utilised. In the en-route part of the scenario no new RNAV functionality will be required: 1. Tactical offsets would not be mandatory and furthermore would not be standardised. This would lead to unpredictable offset behaviour and, as a result, ATC use of this functionality would be limited: it is not expected that offset use to overtake traffic or deconflict routes would be applied despite simulations having shown its operational benefit An airborne capability to meet a time constraint would not be required; therefore en-route flow management based on such capability could only be envisaged for a limited portion of the fleet. 3. Neither FRT nor RNP capability would be required. Therefore optimisation of network route spacing would be even more difficult to accommodate, particularly as a consequence of the growing military airspace needs. 4. There will be no guarantee of a reduction of holding area to permit holds to be placed closer together or in more optimum locations as RNAV holding will not be required for the European fleet. B Terminal Airspace Operations (below FL195 to FAF) There would remain a mixture of requirements for operations in terminal airspace. Without a mandate for P-RNAV, conventional navigation would continue to necessitate the continuing availability of VOR and NDB. In addition, the wide range of RNAV ATS solutions would continue to proliferate in accordance with local TMA needs and considerations which constitute a safety risk (see section B ). CCOs and CDOs might still be developed but lack of vertical management could limit the efficiency of such operations, limit the expected emission reduction and furthermore would not enable the expected pilot and controller workload reduction. Reduced spacing of SIDs or STARs would not be possible, preventing the realisation of capacity improvements and flight efficiency for arrival and departure traffic. B Final Approach Operations Conventional approaches and ILS would largely continue to be used. Despite ICAO Assembly Resolution A37-11, PBN approaches are expected to develop only slowly, in Europe. The status of implementation of PBN approaches can be followed using the PBN Approach map tool available at: 18 Advanced RNP Real Time Simulation Final Report, EUROCONTROL, dated 7 April 2010 Page B-16

17 This situation would prevent the realisation of optimal access to the runway, thus limiting the operators expected benefits. It will also add complexity for ATC and aircraft crew with respect to the number of approaches available as well as training requirements. Based on the current rate of implementation it is anticipated that the 2016 deadline would not be achieved. Therefore the potential for the reduction of CFIT will be delayed thus safety will not be improved as expected (see section B.2.3.4). B State aircraft State aircraft would continue to be accommodated on the basis of exemptions and special handling with negative impacts in terms of capacity, efficiency, environment, predictability and access. B Option 1: Minimum Regulatory Coverage by 2020 Aircraft functionalities for option 1 En-Route Terminal Airspace Final Approach Advanced RNP Advanced RNP APV and LNAV (1NM TSE) (1NM TSE) RF RNAV Holding Ability to meet altitude constraints i.e.: AT, AT OR ABOVE, AT OR BELOW, WINDOWS The key elements of Option 1 are aimed at ensuring a uniform PBN solution with Advanced RNP capability and with full flexibility in terms of TMA operations by B En-route Operations An area navigation system with Advanced RNP capability, (1NM TSE) predicated on GNSS will be required onboard aircraft by the end of Parts of the ATS fixed route network will be adapted in order to reduce the spacing to the minimum achievable distance 20 where identified as contributing to the improvement of the EATMN performance. However the fixed route network adaptation will be limited to straight segments, due to the exclusion of FRT. Potential Stakeholder actions: Aircraft Operators will be required to equip and obtain appropriate approval for the navigation functionalities and performance described above. 19 Date may be different for State aircraft 20 EUROCONTROL Safety Assessment of P-RNAV Route Spacing and Aircraft Separation Final Report (April 2003); Update of P-RNAV study results following IANS simulation (September 2003) Page B-17

18 ANSPs will be required to implement reduced route spacing along straight segments of the fixed ATS route network to enable improved EATMN performance. ANSPs will be required to establish ATC back up procedures in case of GNSS outage. States will be required to approve GNSS as the primary means of navigation. States will be required to ensure that new production state aircraft are equipped and obtain appropriate approval for the navigation functionalities described above by the agreed military implementation date. States will be required to seek performance-based equivalent compliance for non-transport type State aircraft e.g. fighters) to be recognised by national regulators. B Terminal Airspace Operations As for en-route operations, an area navigation system 21 with Advanced RNP capability, (1NM TSE) predicated on GNSS will be required onboard aircraft by in all European TMAs. SIDs and STARs will be designed with reduced route spacing 23 to improve the EATMN performance. The area navigation system required for the en-route part of the flight would be suitable for the TMA in this option. RNAV holding functionality will be required but autopilot coupling would not be required. Based on the foreseen ability to program altitude constraints in the vertical path SIDs and STARs with altitude constraints could be flown with vertical guidance. Autopilot coupling would not be required. Finally, RF functionality will enable the development of procedures with predictable turns in the initial and intermediate phases of the approach. It will be used particularly in the case of terrain and obstacle rich environments or to build new arrival or departure procedures, intended to reduce the extent of noise on a certain route. Potential Stakeholder actions: Aircraft Operators will be required to equip and obtain appropriate approval for the navigation functionalities and performance described above by the end of States will be required to approve GNSS as the primary means of navigation. States will be required to ensure that new production state aircraft are equipped and obtain appropriate approval for the navigation functionalities described above by the agreed military implementation date. States will be offered opportunities to seek performance-based equivalent compliance for non transport-type State aircraft (e.g. fighters) to be recognised by national regulators. 21 Suitable displays are need for situational awareness when flying turns (RF) 22 Date may be different for State aircraft 23 EUROCONTROL Safety Assessment of P-RNAV Route Spacing and Aircraft Separation Final Report (April 2003); Update of P-RNAV study results following IANS simulation (September 2003) Page B-18