Review ICAO Manual on Performance Based Navigation

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Review ICAO Manual on Performance Based Navigation

47TH ANNUAL CONFERENCE, Arusha, Tanzania, 10-14 March 2008

WP No. 91

Review ICAO Manual on Performance Based Navigation

Presented by TOC

Summary

ICAO is introducing the Performance Based Navigation concept to provide a means of achieving harmonisation of RNAV and RNP applications. The PBN Manual sets out issues associated with the identification of the advantages and limitations of choosing one or the other as the navigation requirement for an airspace concept.

TOC has reviewed this manual and this paper provide both (i) a high-level overview to assist member associations in understanding the purpose and direction of the manual and (ii) draft recommendations for a number of amendments to existing IFATCA policy statements to bring them in line with the PBN concept.

Introduction

1.1  ICAO has recently unveiled a Performance Based Navigation (PBN) Manual. The Technical and Operations Committee (TOC) was tasked to review the PBN Manual to determine the impact it may have on Air Traffic Control (ATC) operations in general and the IFATCA Manual specifically.

1.2  In 2003 ICAO set up the Required Navigation Performance and Special Operational Requirements Study Group (RNPSORSG) to develop what has become the PBN concept. This concept encompasses both area navigation (RNAV) and Required Navigation Performance (RNP). The previous RNP concept has been revised.

1.3  The output from the RNPSORSG activity has been the publication of an ICAO Manual which supersedes the previous edition of ICAO Doc 9613 Required Navigational Performance Manual. The document number is retained and the new title is “Performance-Based Navigation Manual”.

1.4  On 27th April 2007 a letter was sent by ICAO to the Member States outlining the PBN concept and providing information regarding a number of PBN presentations at various global locations. Volume II of the manual was attached to this letter.

1.5  When reference is made to ‘the Manual’, ‘PBN Manual’ or ‘this Manual’ in this working paper, it is directly referring to the ICAO Manual on Performance Based Navigation.

Discussion

2.1 The PBN concept

2.1.1  The PBN concept covers both RNAV and RNP. The concept does not introduce anything fundamentally new but is intended to be an umbrella concept that embraces RNAV and RNP. One of the drivers to produce this concept is an attempt to reduce the variety of terminology that was in use for RNAV and RNP applications and attempt to harmonise procedures.

2.1.2  The PBN concept represents a shift from sensor-based to performance-based navigation.

2.1.3  In an attempt to remove the delay associated with introducing new capabilities, the manual introduces an alternative method for defining equipage requirements by specification of the performance requirements. This is termed Performance Based Navigation.

2.1.4  The purpose of the Manual is to introduce harmonisation, speed up implementation and reduce operator cost.

2.1.5  The new PBN Manual is divided into two volumes:

  • Volume 1: Concept and Implementation Guidance
  • Volume 2: Implementing RNAV and RNP

2.2 Volume 1: Concept and Implementation Guidance

2.2.1  Volume 1 explains how a given navigation application with communication, surveillance and Air Traffic Management (ATM) means can support a given airspace concept.

2.2.2  A navigation application is based on:

  • A navigation specification: a set of aircraft and aircrew requirements;
  • A navigation aid infrastructure: ground or space-based navigation aids requirements.

Figure 1: illustration of how PBN fits in the Airspace Concept

2.2.3  There are two kinds of navigation specifications, namely RNAV specifications and RNP specifications. Volume I of the manual clarifies the relationship between RNAV and RNP. The manual recognises that there are many volumes of airspace that already use RNAV, and the current RNAV definition and associated existing navigation specifications are therefore retained. However, the manual redefines the RNP concept. An RNP system is an RNAV system that also includes an ‘onboard navigation performance monitoring and alerting’ (OPMA) function.

2.2.4  The OPMA function allows the crew to detect that the RNP system is not achieving, or cannot guarantee with sufficient integrity (10-5), the navigation performance (in either lateral or longitudinal) required.

2.2.5  RNP is in essence RNAV ‘on steroids’. RNP = RNAV + OPMA.

2.2.6  The manual uses the same methodology for designating both RNAV and RNP specifications. A value is inserted in the navigation specification to indicate the level of navigation performance that the particular specification supports, examples being. RNAV 1 or RNP 4. The numerical value is the navigation accuracy of that navigation specification. However, accuracy is just one of several parameters that combine to create the navigation specification itself.

2.2.7  It is possible for the same value to be shared by navigation specifications. In this event, the specifications may be distinguished by use of a prefix. e.g. Advanced-RNP 1 and Basic-RNP 1.

2.2.8  For both RNAV and RNP designations the numerical value refers to the lateral navigation accuracy in nautical miles that is expected to be achieved at least 95 percent of the flight time by the population of aircraft operating within the airspace, route or procedure.

2.2.9  The diagram below (figure 2) illustrates the different navigation specifications.

2.2.10 The navigation specifications detail:

  • The performance required of the RNAV system in terms of accuracy, integrity, availability and continuity;
  • The navigation functionalities required of the RNAV system in order to meet the required performance;
  • The navigation sensors eligible for the achievement of the required performance; x The requirements placed on the flight crew in order to achieve the required performance from the aircraft and the RNAV system.

In addition RNP Specifications include OPMA requirements.


2.3 Volume 2: Implementing RNAV and RNP

2.3.1  Volume 2 of the PBN manual consists of seven chapters providing the navigation aid infrastructures and the navigation specifications for seven navigation applications (three RNAV applications and four RNP applications.

2.3.2  The chapters in Volume 2 of the PBN Manual provide guidance on how to implement the various RNAV and RNP navigation specifications. The chapters detail issues to be considered, including aircraft equipment, training (both controller and aircrew), publication requirements, communication and surveillance requirements, obstacle clearance, route spacing, navaid infrastructure, phraseology and ATC procedures.

2.3.3  The following RNAV navigation specifications are detailed in Volume II of the manual:

  • RNAV 10
  • RNAV 5
  • RNAV 1

2.3.3.1  The RNAV 10 navigation specification (and the RNP 4 navigation specification listed below) is typically used in oceanic or remote airspace.

2.3.3.2  RNAV 5 is a worldwide standardisation of the European Basic-RNAV (B-RNAV) criteria.

2.3.3.3  RNAV 1 is introduced to provide a harmonised standard from the European P-RNAV and USA RNAV Type A standards.

2.3.4 The following RNP navigation specifications are detailed in Volume II of the manual:

  • RNP4
  • Basic-RNP1
  • RNP APP (RNP Approach)
  • RNP AR APP (RNP Authorization Required Approach)

2.3.4.1 Basic-RNP 1 is a new navigation specification and is intended to provide a means to develop routes for connectivity between the en-route structure and Terminal Areas (TMAs) with no or limited ATS surveillance, with low to medium density traffic. Basic RNP 1 offers a greater degree of integrity and the principle of containment can be applied to the route or procedure. In addition, some new functions are made available, such as Fixed Radius turns (RF legs).

2.3.4.2  RNP APP does not have a set navigation accuracy as this can be varied from location to location. All existing RNAV approaches will be reclassified as RNP APP, as will APV Barometric Vertical Navigation (Baro-VNAV) approaches. New procedure design criteria, based on linear slopes, will be published for these approaches in due course by ICAO. Approach Procedures with Vertical Guidance (APV) I and II are currently outside the scope of the PBN Manual.

2.3.4.3  RNP AR APP are approaches that require special authorisation, hence the ‘Authorisation Required’ (AR) nomenclature. RNP approaches that use a navigation accuracy of less than 0.3NM are classified as RNP AR procedures. The authorisation required could refer to specialist aircrew training as well as potential additional equipment. RNP AR approaches are typically used in locations that have terrain issues that make a conventional instrument approach procedure implausible.

2.3.5 In addition, placeholders for future navigation specifications have been set aside. These are:

  • RNP 2
  • Advanced-RNP 1

2.3.6  The majority of the navigation specifications are not new. They correspond to existing worldwide standards as outlined above. Only BASIC-RNP 1 introduces new standards.

2.3.7  The navigation specifications are intended for use on ATS routes (airways, arrival and departure procedures). The exceptions are:

  • the RNP APP and RNP AR APP navigation specifications which are used to fly instrument approach procedures, and
  • RNAV 10 and RNP standards that are typically used for random routing via lat/long coordinates in oceanic and remote airspace.

2.3.8 It should be noted that with any PBN operation it is possible to use a sequence of RNAV and RNP applications. A flight may commence in an airspace using a Basic RNP 1 SID, transit through en route then oceanic airspace requiring RNAV 2 and RNP 4, respectively, and culminate with terminal and approach operations requiring Advanced RNP 1 and RNP AR APP.

Figure 3: Example of an application of RNAV and RNP specifications to ATS routes and instrument procedures.

2.3.9 The RNP navigation specifications currently defined in the PBN Manual only relate to 2D navigation, i.e. lateral guidance performance and longitudinal position performance.

2.3.10  There are no requirements for vertical OPMA, although RNP AR APP has Barometric VNAV requirements. However, there is no requirement for alerting on vertical position error.

2.3.11  The PBN Manual does not currently include the concept of ‘vertical containment’. The vertical profile is currently referenced to barometric pressure as opposed to geometric height. The APV-I/II applications use geometric height, but these applications are currently outside the scope of the PBN Manual. It is anticipated that ‘vertical containment’ will be included in a future edition of the PBN Manual as this function is required in certain future airspace concepts, such as 4D trajectories.


2.4 PBN manual impact on IFATCA Policy

2.4.1  IFATCA Policy regarding RNAV or RNP has been re-visited to assess what impact, if any, the contents of the PBN manual have. The relevant Policy statements can be found in the IFATCA Manual under “Area Navigation”, “Reguired Navigation Performance for the Approach, Landing and Departure Phases of Flight”, and “Radar Monitoring” are specified below, and are combined with a recommendation to delete, amend or retain the statement. There is often no direct replacement within the PBN Manual for the IFATCA policy statements, which is why the policy statements in principle continue to be valid, although amendments are needed to refer to PBN rather than specifically to RNAV or RNP. Where there is text within the PBN Manual that is appropriate, this is included in the relevant paragraphs..

2.4.2  IFATCA Policy states:

“Controllers should be presented with information, by any suitable means, concerning navigational capability of aircraft under their control.”

 

In general it should not be the controller’s responsibility to ascertain whether or not the pilot can be cleared on a certain route/procedure. However, some ATS routes and procedures may require aircraft to have a certain navigation capability. Where this is the case, the controller should know the navigation capability of aircraft. For example, P- RNAV will be required to operate on some routes in certain European terminal airspace. The spacing of these routes is predicated on aircraft being P-RNAV approved and the controller therefore needs to know that aircraft have this approval. In a similar fashion, some approach procedures will be classified as ‘RNP Authorisation Required’ and the controller will need to be able to determine whether arriving flights qualify for these procedures. No change is required to this policy statement and it should therefore be retained as it currently is.

2.4.3  IFATCA Policy states:

“In airspace where random RNAV routeing are permitted, the ATS system should be capable of processing random RNAV flight plans and controllers should be able to amend/update such information.”

 

The airspace being referred to is typically oceanic or remote continental airspace. An aircraft in such airspace has the freedom of planning direct paths, such as great circle routes. These routes are often not stipulated as an ATS route and are instead defined as a series of RNAV waypoint coordinates. The ATS system used for such airspace needs to be capable of processing this information and presenting it to the controller, who in turn should be able to edit it in order to redirect flights as required for conflict resolution. The general statement should be retained. However, RNAV as referred to in the concept is no longer applicable in this context. The policy should therefore be amended to read:

“In airspace where random routes are permitted, the ATS system should be capable of processing random routeing flight plans and controllers should be able to amend/update such information”.

2.4.4  IFATCA Policy states:

“Track prediction vectors should be available on radar displays used to control airspace where random RNAV procedures are permitted.”

 

As outlined in the paragraph above, random RNAV routes are typically used in oceanic and remote continental airspace. In these areas, alternative means of surveillance, other than radar, are now being used. It is therefore proposed that the wording should be amended so that track prediction vectors should be available on surveillance displays, rather than limiting the statement to only apply to radar displays. The amended wording reads,

“Track prediction vectors should be available on situation displays used to control airspace where random routes are permitted”.

2.4.5  IFATCA Policy states:

“Where the introduction of Precision RNAV procedures entail closely spaced parallel tracks, suitable procedures should be established for the case of loss of navigational accuracy, taking into account such factors as ground equipment capability and controller training.”

 

Under the PBN concept, Precision RNAV (P-RNAV) will no longer exist. The navigation specification that is equivalent of P-RNAV is the RNAV 1 standard. In addition, the Basic-RNP 1 and Advanced-RNP 1 navigation specifications should also be considered for this Policy statement. The requirement contained in the Policy statement for suitable procedures to be in place for instances when navigational accuracy is degraded is sound. Aircraft suffering from a loss of navigational accuracy would normally be provided with headings to fly if in a ATS surveillance environment. Procedures therefore need to be in place to ensure that controllers are aware of the actions to be taken in the event of such a loss of navigational accuracy occurring.

The wording in the Policy statement implies that such procedures only need to be in place where closely spaced parallel tracks are used. However, such procedures would also need to be available where tracks predicated on RNAV or RNP are closely spaced, including instances on converging and diverging tracks, as a loss of navigational accuracy would also have an impact for such tracks as well. The requirement for suitable procedures to be in place should not be limited only to closely spaced parallel tracks. It is proposed that the re-worked sentence would read,

“Where the introduction of PBN procedures entail closely spaced parallel tracks, suitable procedures should be established for the case of loss of navigational performance, taking into account such factors as ground equipment capability and controller training”.

2.4.6  IFATCA Policy states:

“Adequate training must be provided for controllers managing RNAV operations; such items as RTF phraseology, co-ordination procedures and conflict identification need to be considered.”

 

The introduction of Performance Based Navigation techniques will significantly change the way in which ATC is provided in some airspace. The use of RNAV and RNP routes and procedures will enable aircraft to operate on their own navigation at distances close to the separation minima. The amount of tactical intervention by the controller is likely to decline whilst the monitoring task will increase.

The PBN Manual refers to controller training in Volume II, Part B, where implementing the various RNAV and RNP standards is referred to. However, the proposals for training focus upon technical knowledge of the RNAV or RNP application in use in the airspace concerned, rather than the operational changes required as a result of the shift from a tactical to a monitoring environment.

This change to the way in which ATC is provided will require the controllers to be trained in new techniques and skills. For this reason, the policy statement continues to be valid, although it should be broadened out to cover both RNAV and RNP. This could be achieved by the replacing the words ‘RNAV operations’ with ‘PBN operations’. The amended policy statement would read,

“Adequate training must be provided for controllers managing PBN operations; such items as RTF phraseology, co- ordination procedures and conflict identification need to be considered”.

2.4.7  IFATCA Policy states:

“IFATCA should ensure that controllers’ expertise is used in the deliberations taking place to provide appropriate specifications for the use of RNAV.”

 

The move towards PBN operations, predicated on either RNAV or RNP, will result in a change in the way in which ATC is undertaken. Controllers should therefore always be engaged in the process of introducing navigational specifications to ensure that consideration is given to ATC issues. The policy statement continues to be valid, although it should be broadened out to cover both RNAV and RNP. This could be achieved by the replacing the words ‘RNAV’ with ‘PBN’. The amended policy statement would read,

“IFATCA should ensure that controllers’ expertise is used in the deliberations taking place to provide appropriate specifications for the use of PBN.”

2.4.8  IFATCA Policy states:

“RNAV route structures must be designed to ensure that ATC workload is not increased and, where possible, it is reduced in spite of increased traffic.”

 

Some forms of PBN can enable ATS routes or procedures to be spaced closer together. This could result in an increase in capacity for the airspace and potentially an increase in traffic. It is an important airspace design best practice that controller workload should be kept at a manageable level with the introduction of RNAV routes and procedures. For instance, where possible any requirement for compulsory tactical intervention in a time critical manner should be avoided in the design of the routes. Instead, consideration could be given to implementing routes that strategically separate the flows of traffic thereby reducing ATC workload.

The policy statement continues to be valid, although it should be broadened out to cover both RNAV and RNP by using the term PBN. In addition, the policy statement is currently limited to routes. The policy is equally applicable for procedures, such as standard instrument departures or arrival transitions. The policy should cover both routes and procedures. The proposed amended statement reads,

“PBN route structures or procedures must be designed to ensure that ATC workload is manageable and, where possible, workload is reduced in spite of increased traffic“.

2.4.9  IFATCA Policy states:

“RNAV standards should be harmonized throughout the world. Harmonisation will result in common standards, decreasing the diverse types of RNAV procedures that are currently encountered by air crews operating around the world.”

 

The publication of the PBN Manual is an attempt by ICAO to meet this requirement outlined in the policy statement. One of the prime drivers behind the PBN concept is the need to start to harmonise RNAV and RNP procedures. This is because a plethora of variations of RNAV procedures had started to spring up a few years ago.
Even though the PBN Manual is a catalyst for harmonising RNAV procedures, the policy statement should stay in force until such time as all the States have complied with the PBN concept and the number of variations of RNAV has been reduced to those defined in the Manual. The current policy statement refers only to RNAV whereas the need for harmonisation is equally applicable for RNP. It is therefore proposed to amend the policy statement so that it reads,

“PBN standards should be harmonized throughout the world. Harmonisation will result in common standards, decreasing the diverse types of PBN procedures that are currently encountered by air crews operating around the world“.

2.4.10  IFATCA Policy states:

“Any introduction of RNAV/RNP routes that are spaced below the current non RNAV/RNP route spacing, with the intention to increase capacity, must be accompanied by the introduction of accurate automated monitoring assistance for the controller.”

 

The PBN concept includes navigation specifications that offer the ability for aircraft to fly routes and procedures with a high level of accuracy. This capability enables the spacing between routes to be reduced. In turn, the reduction in route spacing may provide the opportunity to increase capacity in a given volume of airspace.

This Policy statement suggests that any reduction in route spacing resulting from the introduction of RNAV/RNP routes that enables airspace capacity to be increased must be accompanied by automated monitoring assistance for controllers. The statement, whilst originally being well intended, may be susceptible to challenge in today’s PBN environment.

RNP provides on board performance monitoring and alerting, whilst RNAV alone does not. It could therefore be the case that routes that are spaced at reduced distances based on the use of RNAV require automated monitoring assistance for controllers. However, the requirement for routes that are spaced at reduced distances based on the use of RNP to have automated monitoring assistance becomes weaker due to the fact that the aircraft are fitted with on board performance monitoring and alerting. Whilst it continues to be sensible to require automated monitoring for RNAV routes, the requirement for automated monitoring for RNP routes is less compelling.

The design of the airspace, and specifically the interaction between the routes, should also be a consideration when determining whether automated monitoring is required. RNAV routes may be spaced at reduced distances when compared to routes predicated upon conventional navaids, but the geometry may be such between the routes that automated monitoring is not required.

The PBN Manual stipulates in para 2.2.3 that:

“The State is responsible for route spacing and should account for the availability of ATS surveillance and monitoring tools to support detection and correction of navigation errors“.

ICAO is therefore leaving the matter of route spacing and the potential requirement for monitoring tools to individual States.

The airspace design will be a factor in whether automated monitoring is required and a blanket requirement for automated monitoring is not therefore applicable and such a requirement should be assessed on a case by case basis, normally by mean of a safety analysis. It is a basic requirement from ICAO to undertake such a safety analysis, to produce a safety case and demonstrate safety.

The policy statement is therefore re-worded to reflect the content of the paragraphs above. The amended statement reads,

“Any introduction of PBN routes that are closely spaced should be subjected to safety analysis. Such a safety analysis may result in hazards being identified that require automated monitoring assistance for the controller to adequately mitigate the hazard”.

2.4.11  IFATCA Policy states:

“Any introduction of Precision RNAV/RNP routes should ensure that controllers can, upon identification or notification of a deviation, carry out the necessary action so that the required separation minima are not likely to be infringed.”

 

This statement is highlighting the requirement for RNAV and RNP routes to be spaced further apart than the required separation minima for that specific airspace. This requirement is in place to ensure that there is sufficient time prior to a loss of separation for a controller to react, determine a solution and pass appropriate instructions to the aircraft concerned upon identifying or being notified of a flight deviating outside of the tolerance associated with the RNAV or RNP value for a given route. A number of factors, including the complexity and density of traffic in the airspace, should be taken into account when determining how much further apart than the required separation minima the routes should be spaced to allow for the capability of the controller to intervene. It is proposed that the policy statement is amended to broaden the statement so that it highlights the route spacing issue to be considered by MAs when such closely spaced routes are implemented. The proposed amended statement reads,

“Any introduction of closely spaced routes should ensure that controllers can, upon identification or notification of a deviation, carry out the necessary action so that the required separation minimum is not likely to be infringed“.

2.4.12  IFATCA Policy states:

“RNP based operational procedures should be developed in parallel with new approach aids such as MLS and GNSS and should, ideally, be introduced at the same time as these new aids. After the introduction of a new aid, the full benefits of RNP may not be achieved while ILS is still in use.

A significant factor in the determination of RNP procedures should be the aim of limiting ATC workload.”

 

RNP approach procedures are an integral part of the PBN concept. There are RNP approaches in operational use in a variety of locations around the world today. RNP approaches are principally flown using GNSS as the primary navigation sensor. The first part of the policy statement has therefore been partially achieved as the vast majority of RNP approaches require GNSS as the navigation source. This is supported by the PBN Manual which states in para 5.2.3 that

“GNSS is the primary navigation system to support RNP APP procedures“.

In many countries, RNP procedures are being used to achieve minima approaching that of a Cat I ILS. precision approach capability is still provided in the vast majority of locations by ILS. There are a couple of locations were Microwave Landing System (MLS) is in the process of being introduced. RNP precision approach capability can be achieved through the use of a Ground Based Augmentation System (GBAS). However, these systems are still on operational trial and are not yet deployed operationally on a permanent basis.

RNAV approaches continue to exist and are in operation in a number of States. The intention is to make necessary changes to PANS-OPS that will amend the design criteria for RNAV approaches. The nature of this change is to alter the shape of the protected area by removing the trapezoidal sloping sides and replace them with linear sides. However, whilst this is an intended change to PANS-OPS, it hasn’t yet been enacted so as the situation currently stands both RNP and RNAV approaches exist. However, as the intention is to progress towards reclassifying RNAV approaches as RNP ones, it is suggested that the policy statement continues to refer to RNP based procedures.

The initial sentence in the policy statement continues to be a valid point. However, the next 2 sentences offer nothing new and the issue of controller workload being kept at a manageable level has already been addressed in a previous policy statement in this paper. The policy statement should therefore be amended to reflect this and the proposed amended statement reads,

“RNP based operational procedures should be developed in parallel with new approach aids, such as GNSS.”

Conclusions

3.1  The PBN Manual is an attempt to capture the various RNAV and RNP standards to introduce a degree of harmonisation on a global basis and to provide guidance on how to set about implementing RNAV and RNP. To this end, the manual achieves its aims quite well. However, there are still additional areas of PBN that are not yet included in the manual. For instance, APV-I and APV-II are not included at the moment. It is recognised by ICAO that further updates to the manual will be required.

3.2  Despite the title of the concept, the requirements are not totally ‘performance based’ and are not independent of specific technology. The aircraft requirements are determined after an allocation of the required overall performance to the ground domain and the airborne domain. This allocation is not independent of the specific technology. In addition, the number of available technologies is limited. For example, to operate using the RNP 4 specification there is only one technology currently available, namely GPS, and the associated navigation specification requires the use of this technology.

3.3  A review of IFATCA Policy indicates that there are several Policy statements that have been written in the past either specifically for RNAV or for RNP. These statements should be updated where applicable to accommodate both RNAV and RNP and therefore be aligned with the umbrella PBN concept.

3.4  The Policy statement regarding the requirement for automated monitoring for RNAV and RNP routes where the spacing is less than that for existing conventional routes and as a result traffic can be increased needs to be reconsidered. The requirement for automated monitoring is a blanket one that does not differentiate between the respective capabilities of RNAV and RNP aircraft. Airspace design should also be considered on a case by case basis before stipulating that automated monitoring is required. The PBN Manual stipulates that it is up to States to determine the appropriate route spacing criteria to be used.

Recommendations

It is recommended that;

4.1  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

In airspace where random RNAV routeing are permitted, the ATS system should be capable of processing random RNAV flight plans and controllers should be able to amend/update such information.

is amended to read:

In airspace where random routes are permitted, the ATS system should be capable of processing random routeing flight plans and controllers should be able to amend/update such information.

4.2  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

Track prediction vectors should be available on radar displays used to control airspace where random RNAV procedures are permitted.

is amended to read:

Track prediction vectors should be available on situation displays used to control airspace where random routes are permitted.

4.3  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

Where the introduction of Precision RNAV procedures entail closely spaced parallel tracks, suitable procedures should be established for the case of loss of navigational accuracy, taking into account such factors as ground equipment capability and controller training.

is amended to read:

Where the introduction of PBN procedures entail closely spaced parallel tracks, suitable procedures should be established for the case of loss of navigational performance, taking into account such factors as ground equipment capability and controller training.

4.4  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

Adequate training must be provided for controllers managing RNAV operations; such items as RTF phraseology, co-ordination procedures and conflict identification need to be considered.

is amended to read:

Adequate training must be provided for controllers managing PBN operations; such items as RTF phraseology, co-ordination procedures and conflict identification need to be considered.

4.5  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

IFATCA should ensure that controllers’ expertise is used in the deliberations taking place to provide appropriate specifications for the use of RNAV.

is amended to read:

IFATCA should ensure that controllers’ expertise is used in the deliberations taking place to provide appropriate specifications for the use of PBN.

4.6  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

RNAV route structures must be designed to ensure that ATC workload is not increased and, where possible, it is reduced in spite of increased traffic.

is amended to read:

PBN route structures or procedures must be designed to ensure that ATC workload is manageable and, where possible, workload is reduced in spite of increased traffic.

4.7  IFATCA Policy on page 3 2 1 6 of the IFATCA Manual:

RNAV standards should be harmonized throughout the world. Harmonisation will result in common standards, decreasing the diverse types of RNAV procedures that are currently encountered by air crews operating around the world.

is amended to read:

PBN standards should be harmonized throughout the world. Harmonisation will result in common standards, decreasing the diverse types of PBN procedures that are currently encountered by air crews operating around the world.

4.8  IFATCA Policy on page 3 2 3 9 of the IFATCA Manual:

Any introduction of RNAV/RNP routes that are spaced below the current non RNAV/RNP route spacing, with the intention to increase capacity, must be accompanied by the introduction of accurate automated monitoring assistance for the controller.

is amended to read:

Any introduction of PBN routes that are closely spaced should be subjected to safety analysis. Such a safety analysis may result in hazards being identified that require automated monitoring assistance for the controller to adequately mitigate the hazard.

4.9  IFATCA Policy on page 3 2 3 9 of the IFATCA Manual:

Any introduction of Precision RNAV/RNP routes should ensure that controllers can, upon identification or notification of a deviation, carry out the necessary action so that the required separation minima are not likely to be infringed.

is amended to read:

Any introduction of closely spaced routes should ensure that controllers can, upon identification or notification of a deviation, carry out the necessary action so that the required separation minimum is not likely to be infringed.

4.10  IFATCA Policy on page 3 2 2 11 of the IFATCA Manual:

RNP based operational procedures should be developed in parallel with new approach aids such as MLS and GNSS and should, ideally, be introduced at the same time as these new aids. After the introduction of a new aid, the full benefits of RNP may not be achieved while ILS is still in use.

A significant factor in the determination of RNP procedures should be the aim of limiting ATC workload.

is amended to read:

RNP based operational procedures should be developed in parallel with new approach aids, such as GNSS.

References

ICAO Doc 9613 Performance-Based Navigation Manual.

JAA CNS/ATM Steering Group position paper on Performance Based Navigation (PP044_01)

Last Update: September 29, 2020  

April 11, 2020   146   Jean-Francois Lepage    2008    

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