Performance-Based Navigation. This folder contains ten canonical files providing a structured deep dive into PBN: the navigation concept, the specification catalogue, implementation by flight phase, the RNP approval chain, enablers, performance objectives, and timeline.

Files in this folder#

Recommended reading order#

1. overview.md — understand the concept and its place in CNS/ATM
2. components.md — the three-component PBN model
3. blocks.md — the full navigation specification catalogue by phase
4. threads.md — functional axes that cut across specifications
5. modules.md — the RNP APCH / LPV worked example
6. enablers.md — what must be in place to run PBN operations
7. performance_objectives.md — what PBN delivers, measured
8. timeline.md — how we got here
9. references.md — primary sources

Source basis#

Primary source: Doc 9613 (PBN Manual, 5th Edition 2023), present in the local ICAO library at mds/Documents/9613_cons_en.md. Supporting sources: Doc 9997 (PBN Operational Authorization Manual, 3rd Edition 2024), Doc 9992 (Manual on the Use of PBN in Airspace Design, 1st Edition 2013), Annex 6 Parts I/II/III, Doc 8168 (PANS-OPS Volumes I and II), Doc 9905 (RNP AR Procedure Design Manual). All files in this folder are clean for web-app use: no local library paths, no shell commands.

What is PBN?#

Performance-Based Navigation (PBN) is the ICAO concept for specifying navigation requirements in terms of performance — accuracy, integrity, continuity and functionality — rather than in terms of which on-board sensor or ground-based navigation aid must be used. The concept is defined in Doc 9613 (PBN Manual) and is the normative framework for all RNAV and RNP navigation specifications used in civil aviation.

The term "performance-based" has a precise meaning: the airspace designer or procedure designer defines what the aircraft navigation system must achieve (the performance), and operators select technology that meets that performance. This sensor agnosticism is the central contribution of PBN to global harmonization. An RNAV 1 arrival procedure in Pakistan can be flown by an aircraft using GNSS, an aircraft using DME/DME, or an aircraft using DME/DME/inertial — provided the chosen sensor meets the 1 NM accuracy requirement. The procedure does not change for each sensor.

Where PBN sits in the ICAO/ATM framework#

PBN is one of three pillars of the CNS (Communications, Navigation, Surveillance) infrastructure that underpins the ATM system. Navigation is the pillar that determines where an aircraft is and where it will go. PBN defines the performance standards for the navigation pillar, enabling an area navigation (RNAV) capability that is not dependent on overflying specific ground aids.

Within the GANP and ASBU framework, PBN is primarily addressed through the NAVS (Navigation Services) technology thread. The APTA (Optimization of Approach Procedures including Vertical Guidance) operational thread targets PBN approach implementation. Key ASBU modules:

• APTA-B0: PBN approaches with vertical guidance (LPV / baro-VNAV / RNP APCH) — the baseline mandate.
• APTA-B1: Advanced PBN approaches including RNP AR APCH with RF legs.
• NAVS-B2: Multi-constellation, multi-frequency GNSS as primary means of navigation, supporting next-generation PBN precision.

PBN is also an enabler for other ATM capabilities. Trajectory-Based Operations (TBO) depend on PBN providing the onboard path accuracy required for 4D trajectory conformance. Continuous Descent Operations (CDO) and Continuous Climb Operations (CCO) are designed using PBN specifications (RNAV 1 or RNP 1 STARs/SIDs) to publish optimized vertical profiles.

RNAV versus RNP: the critical distinction#

All PBN operations are area navigation operations. The distinction between RNAV and RNP navigation specifications is functional, not a matter of accuracy level:

RNAV navigation specification. The navigation system must meet the accuracy requirement (the RNAV value in nautical miles, 95% of flight time). There is no requirement for the system itself to monitor whether it is meeting that requirement. External means — radar surveillance, pilot reports, or administrative airspace design margins — provide the safety net.

RNP navigation specification. The navigation system must meet the accuracy requirement AND must continuously monitor whether it is doing so. On-board performance monitoring and alerting (OBPMA) is mandatory. If the estimated position uncertainty (EPU) exceeds the RNP value, the navigation system alerts the crew. The crew can then take contingency action: abandon the procedure, revert to alternate navigation, or declare an emergency.

The OBPMA requirement of RNP allows:

• Tighter route and procedure spacing (the safety margin is internally controlled, not added externally).
• Operations in non-radar environments with the same or better safety level as radar-supervised RNAV operations.
• Reduced separation minima in oceanic airspace where ground-based surveillance is absent (RNP 4 enables 50 NM lateral separation with ADS-C).

The three-component PBN model#

Doc 9613 describes PBN as comprising three components that interact to produce a navigation application:

1. Navigation specification — the technical standard: accuracy, integrity, continuity, functionality, eligible sensors. Defined in Doc 9613 Volume II for each named specification.
2. NAVAID infrastructure — the positioning service: GNSS (GPS, GLONASS, Galileo, BeiDou; and augmentations SBAS, GBAS, ABAS/RAIM) or ground-based aids (DME, VOR, NDB). Requirements in Annex 10.
3. Navigation application — the specific use: a route, a SID, a STAR, an instrument approach procedure, or a designated airspace volume. Designed using the navigation specification and NAVAID infrastructure for a defined airspace concept.

The navigation application is the only "dynamic" component: the same RNAV 1 specification can produce dozens of different SIDs and STARs at different airports. The specification and the infrastructure are fixed standards; the application is designed case-by-case.

PBN in the global mandate chain#

ICAO Assembly Resolution A37-11 (37th Session, 2010) directed all Contracting States to implement PBN on all ICAO routes and at all instrument runways by 2016. The mandate covered: en-route and terminal RNAV/RNP operations; and RNP APCH at every instrument runway as the baseline approach procedure. Subsequent assembly resolutions (A38-12 2013, A40-11 2019) tracked progress and reinforced the mandate, acknowledging that many developing States would require technical assistance to complete implementation.

As of the 5th Edition of Doc 9613 (2023), PBN implementation is considered the baseline for all States. Work continues on next-generation specifications (dual-frequency multi-constellation GNSS supporting DFMC SBAS approaches) and on integrating RPAS/UAS requirements into the PBN framework.

References#

• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.1.1 — PBN concept: the shift from sensor-based to performance-based navigation.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.1.2 — Benefits of PBN: reduced sensor-specific cost, technology-agnostic operations, improved airspace efficiency.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.1.3 — PBN context within the airspace concept alongside communications, surveillance and ATM.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.1.2 — RNAV vs RNP distinction: OBPMA as the defining functional difference.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.2.1 — On-board performance monitoring and alerting: definition and role in safety.
• Annex 6 Part II, §1.1 Definitions — Formal ICAO SARP definition of PBN.
• Doc 9750 (GANP), ASBU Thread APTA — PBN approaches as Block 0 baseline and Block 1 advanced capability (authoritative source — not in local library; see https://ganpportal.icao.int/).

The PBN triad#

Every PBN operation is the intersection of three components. No PBN application can exist without all three. Doc 9613 Volume I, §1.1.3 describes this triad explicitly: "PBN relies on the use of area navigation and comprises three components."

The three components are:

• Navigation specification — the performance standard for the aircraft navigation system.
• NAVAID infrastructure — the positioning service (ground- or space-based) that feeds the aircraft navigation system.
• Navigation application — the specific use of the specification and infrastructure in the context of an airspace concept.

Component 1: Navigation specification#

Definition#

A navigation specification is a set of aircraft and aircrew requirements needed to support PBN operations within a defined airspace. It is the technical standard against which airworthiness and operational approval are assessed. A navigation specification defines:

• Accuracy — the RNP or RNAV value in nautical miles (95% of flight time for the population of aircraft).
• Integrity — the probability that the navigation system is operating within performance limits without alerting.
• Continuity — the probability that the system maintains required performance for the duration of an operation.
• Functionality — required path terminator types (TF, CF, RF, etc.), parallel offset capability, time of arrival control, baro-VNAV, SBAS, and other features that must be present.
• OBPMA requirement — whether on-board performance monitoring and alerting is mandatory (RNP) or not (RNAV).
• Eligible sensors — which navigation inputs (GNSS, DME/DME, inertial, SBAS, GBAS) may be used to meet the performance.
• Authorization process — whether a general operational authorization or a specific (AR) approval from the State of Registry is required.

RNAV vs RNP: the key functional split#

Doc 9613 §1.2.1.2 states: "A navigation specification is either an RNP navigation specification or an RNAV navigation specification. An RNP navigation specification includes a requirement for on-board performance monitoring and alerting, while an RNAV navigation specification does not."

This distinction determines the safety architecture:

On-board performance monitoring and alerting (OBPMA)#

OBPMA is the mechanism that makes RNP specifications self-monitoring. The navigation system (typically the FMS) continuously computes an estimated position uncertainty (EPU), which represents a 95% confidence bound on horizontal position error. It compares EPU with the RNP value for the active operation. If EPU is less than or equal to RNP, the operation continues. If EPU exceeds RNP, the system generates an alert.

Doc 9613 §1.2.2.1 identifies three functions of OBPMA:

a) Determining whether the navigation system supports the safety level associated with an RNP application.

b) Relating to both lateral and longitudinal navigation performance.

c) Allowing the crew to detect when the navigation system cannot guarantee with sufficient integrity the navigation performance required for the operation.

OBPMA transforms navigation from a "best-effort" function into a continuously validated safety function. This is why RNP systems may offer "significant safety, operational and efficiency benefits over RNAV systems" (Doc 9613 §1.2.2.2).

Component 2: NAVAID infrastructure#

The NAVAID infrastructure is the positioning service on which the aircraft navigation system relies. Doc 9613 §1.3 defines it as ground- or space-based NAVAIDs. All NAVAID requirements are defined in Annex 10 (Aeronautical Telecommunications).

Ground-based NAVAIDs#

• VOR (VHF Omnidirectional Range) — provides magnetic bearing; usable for RNAV 5 as a sensor for FMS DME/VOR positioning.
• DME (Distance Measuring Equipment) — provides slant range; DME/DME positioning is the primary ground-based RNAV sensor for RNAV 1/2/5.
• NDB (Non-Directional Beacon) — not listed as an eligible sensor for any PBN specification in Doc 9613; only for conventional procedures.

Under PBN, ground-based NAVAIDs are sensors that may satisfy the performance requirement; they are not the route definition. This enables NAVAID rationalisation: once GNSS coverage is sufficient, some redundant VOR/NDB infrastructure can be consolidated without redesigning PBN procedures.

Space-based NAVAIDs (GNSS)#

GNSS is the primary navigation infrastructure for most PBN operations. Doc 9613 recognizes the following GNSS elements:

• Core constellations: GPS (USA), GLONASS (Russia), Galileo (EU), BeiDou (China). Annex 10 Volume I SARPs currently cover GPS and GLONASS; work is ongoing for Galileo and BeiDou.
• ABAS/RAIM — aircraft-based augmentation; RAIM checks GPS signal consistency using redundant pseudo-ranges. The primary integrity source for oceanic and en-route RNP operations.
• SBAS (Satellite-Based Augmentation System) — ground network monitors GNSS and broadcasts corrections and integrity data via geostationary satellite. Enables approach operations to LPV minima (RNP APCH LP/LPV lines of minima). Systems: WAAS (USA), EGNOS (Europe), MSAS (Japan), GAGAN (India).
• GBAS (Ground-Based Augmentation System) — local ground reference at an aerodrome; broadcasts differential corrections for precision approach (GLS). Highest accuracy; not part of the PBN Manual navigation specifications (ILS/GLS precision approaches are excluded from PBN scope).

Dual-frequency multi-constellation (DFMC)#

Doc 9613 §1.6.2 introduces the DFMC evolution: all four core constellations are developing second signals, and SBAS/ABAS standards are evolving to support them. DFMC GNSS provides improved availability, accuracy and integrity. The DFMC concept of operations enables next-generation PBN operations planned for ASBU Block 2 (NAVS-B2 module from 2025).

Component 3: Navigation application#

A navigation application is "the use of a navigation specification and associated NAVAID infrastructure for ATS routes, instrument approach, departure or arrival procedures and/or to enable user-defined routeing in a specified airspace volume in accordance with the airspace concept" (Doc 9613 §1.4.1).

The navigation application is the only PBN component that is not static. The same RNAV 1 specification can support hundreds of different SIDs and STARs at different airports, in different States, with different NAVAID infrastructure choices. The specification remains constant; only the application changes.

Application types#

• ATS route — a published track connecting waypoints; the navigation specification defines the route-spacing criteria (e.g. RNP 4 routes in oceanic airspace are spaced at 50 NM laterally).
• Standard Instrument Departure (SID) — a published departure procedure from runway end to the en-route structure.
• Standard Instrument Arrival (STAR) — a published arrival procedure from the en-route structure to the initial approach fix.
• Instrument approach procedure (IAP) — the complete procedure from the initial approach fix through the missed approach.
• User-defined routeing — free route airspace operations where the flight crew files a direct track; the navigation specification governs accuracy on that track.

Application and infrastructure interaction#

Doc 9613 §1.4.3 illustrates that the same specification can require different infrastructure in different States. An RNAV 1 application in a State with only GNSS published requires GNSS-capable aircraft. The same RNAV 1 application in a State with a dense DME network may accept DME/DME-only aircraft. The specification (RNAV 1) does not change; the State's published infrastructure constraint does.

This means aircraft approved to RNAV 1 in one State are not automatically approved for every RNAV 1 application in another State — operator authorization must verify that the aircraft's sensors match the infrastructure required in the destination State's AIP.

References#

• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.1.3 — PBN comprises three components: navigation specification, NAVAID infrastructure, navigation application.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.1.1 — Navigation specification: a set of aircraft and aircrew requirements for PBN operations within a defined airspace concept.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.1.2 — RNAV vs RNP classification based on OBPMA requirement.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.2.1 — OBPMA: three functions — safety support, lateral/longitudinal coverage, crew alerting.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.2.2.2 — RNP OBPMA advantage over RNAV for safety, operations, and efficiency.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.3 — NAVAID infrastructure: ground-based (DME, VOR) and space-based (GNSS); Annex 10 requirements.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.4.1 — Navigation application definition and its dynamic character.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.6.2 — DFMC GNSS evolution and its impact on future PBN operations.
• Annex 10 (Aeronautical Telecommunications), Volume I — GNSS SARPs covering GPS, GLONASS and augmentation systems.

Organizing principle#

In the PBN context, "blocks" maps to the navigation specification families organized by flight phase. Each family groups the specifications appropriate to an airspace domain — oceanic/remote, continental en-route, terminal, and approach. Within each family, a progression from less stringent to more stringent specifications mirrors the shift from RNAV (no OBPMA) toward RNP (OBPMA mandatory), with accuracy values tightening as the flight phase demands closer obstacle clearance.

Doc 9613 Volume II carries the full technical detail for each specification. The chart below shows the complete catalogue.

Family 1: Oceanic and remote continental#

Oceanic and remote airspace is characterised by the absence of ground- based surveillance, limited communications, and the inability to provide standard radar separation. Navigation specifications for this domain all rely primarily on GNSS and are combined with ADS-C and CPDLC to form the complete airspace concept.

RNAV 10 (RNP 10)#

• Accuracy: 10 NM
• OBPMA: not required
• Eligible sensors: GNSS, long-range INS
• Status: Doc 9613 (5th Ed) notes RNAV 10 is "considered archaic" relative to RNP 4. Existing routes and operational authorizations retain the legacy RNP 10 designation; re-designating the entire route network is not cost-effective. New applications should use RNP 4.
• Application: North Atlantic Track System (NAT), Pacific tracks where RNP 4 has not yet been implemented.

RNP 4#

• Accuracy: 4 NM
• OBPMA: required
• Eligible sensors: GNSS (primary)
• Separation enabled: 50 NM lateral, 50 NM longitudinal (with ADS-C/CPDLC procedures); enables reduced vertical separation on some routes.
• Application: NAT HLA (North Atlantic High Level Airspace) when full PBCS/CPDLC/ADS-C is in place; Pacific oceanic routes.

RNP 2#

• Accuracy: 2 NM
• OBPMA: required
• Eligible sensors: GNSS
• Application: Oceanic/remote and continental en-route; used in Australia (AUSOTS), Canada, and continental remote regions where radar coverage is absent or limited.

Family 2: Continental en-route#

Continental en-route airspace typically has radar surveillance, VHF communications, and reasonably dense DME infrastructure. This environment supports a mix of RNAV and, increasingly, RNP specifications.

RNAV 5#

• Accuracy: 5 NM
• OBPMA: not required
• Eligible sensors: GNSS, DME/DME, VOR/DME, inertial
• Application: The standard en-route specification across ICAO EUR and most other regions. Used for fixed ATS routes (Q/T/UL/UM routes in European airspace) and for direct-track operations.

RNAV 2#

• Accuracy: 2 NM
• OBPMA: not required
• Eligible sensors: GNSS, DME/DME, DME/DME/inertial
• Application: Continental Q/T routes in the United States; growing use in other regions for denser en-route route structures.

RNAV 1#

• Accuracy: 1 NM
• OBPMA: not required
• Eligible sensors: GNSS, DME/DME, DME/DME/inertial
• Application: En-route and terminal (SID/STAR); the workhorse terminal RNAV specification in radar-equipped environments.

Family 3: Terminal (SID/STAR)#

Terminal airspace specifications must support the procedure design criteria for departures and arrivals. The tighter accuracy requirements and the addition of OBPMA in RNP 1 enable analytically derived route spacing without reliance on surveillance monitoring.

RNP 1#

• Accuracy: 1 NM
• OBPMA: required
• Eligible sensors: GNSS (primary); some DME/DME combinations
• Application: SIDs and STARs in procedural or low-density terminal airspace. Enables parallel tracks to be spaced tighter than equivalent RNAV 1 tracks. Originally developed for procedural (non-radar) terminal airspace; now widely used alongside radar.

Advanced RNP (A-RNP)#

• Accuracy: Variable — 2 NM or 1 NM en-route/terminal, 0.3 NM on final approach segment (note: final approach segment no longer formally part of A-RNP in 5th Edition, aligning with Doc 8168 Vol II criteria).
• OBPMA: required
• Required functionality: RF legs (mandatory); parallel offset (optional); time of arrival control (optional); scalable RNP value removed in 5th Edition.
• Application: Complex terminal environments where curved departure or arrival paths are needed (terrain avoidance, noise routing, complex airspace geometry). A-RNP SIDs/STARs can embed RF leg segments.

Family 4: Approach#

Approach specifications must meet the most stringent accuracy and integrity requirements in the PBN catalogue because obstacle clearance in the final approach segment depends critically on lateral (and sometimes vertical) precision.

RNP APCH#

• Accuracy: 1 NM in initial/intermediate, 0.3 NM in final approach
• OBPMA: required
• Vertical guidance options: Baro-VNAV (LNAV/VNAV), SBAS (LP/LPV)
• Lines of minima:
  • LNAV — lateral navigation only (non-precision approach minima)
  • LNAV/VNAV — lateral plus baro-VNAV vertical (APV Type A)
  • LP — lateral with SBAS (APV Type A, DME-like lateral only)
  • LPV — lateral plus SBAS vertical guidance (APV Type I/II); enables decision altitude as low as 200 ft, approaching ILS Category I performance
• Status: The ICAO mandate specification — required at all instrument runways globally. Most States have or are completing RNP APCH implementation.

RNP AR APCH (Authorization Required)#

• Accuracy: Variable down to 0.1 NM; RF legs permitted in final approach and missed approach segments
• OBPMA: required
• Authorization: Specific approval from State of Registry mandatory (Annex 6 Part II §2.5.2.5). Procedure design requires separate authorization from the State of the aerodrome per Doc 9905.
• Functionality: RF legs with predictable, repeatable curved paths; missed approach with RF possible; variable RNP value across segments.
• Application: Terrain-constrained airports (mountain valleys); noise-sensitive airports needing curved paths; airports where straight- in ILS is geometrically unavailable. Example: curved RNP AR APCH into Kathmandu (VNKT), Queenstown (NZQN), Innsbruck (LOWI).

RNP 0.3 (Helicopter only)#

• Accuracy: 0.3 NM
• OBPMA: required
• Eligible aircraft: Helicopters exclusively (5th Edition 2023 explicitly clarified this — no fixed-wing application).
• Application: Helicopter terminal procedures including point-in- space (PinS) approach procedures at heliports and offshore platforms.

Navigation specification comparison matrix#

References#

• Doc 9613 (PBN Manual), Volume II, Part B, Chapter 1 — RNAV 10 navigation specification.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 1 — RNP 4 navigation specification.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 2 — RNP 2 navigation specification.
• Doc 9613 (PBN Manual), Volume II, Part B, Chapter 2 — RNAV 5 navigation specification.
• Doc 9613 (PBN Manual), Volume II, Part B, Chapter 3 — RNAV 1 and RNAV 2 navigation specifications.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 3 — RNP 1 navigation specification.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 4 — Advanced RNP (A-RNP) navigation specification; 5th Edition refinements.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 5 — RNP APCH navigation specification; LNAV, LNAV/VNAV, LP and LPV lines of minima.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 6 — RNP AR APCH navigation specification; RF legs in approach and missed approach.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 7 — RNP 0.3 navigation specification; explicitly helicopter-only.
• Doc 9613 (PBN Manual), Volume I, §1.2.4.5 — RNAV 10 retention of RNP 10 designation; rationale for not renaming existing authorizations.
• Doc 9905 (RNP AR Procedure Design Manual) — Procedure design criteria for RNP AR APCH and RNP AR departure procedures (authoritative source — not in local library).

Organizing principle#

In the PBN context, "threads" map to the functional axes that cut across the navigation specification families. Where the blocks file organizes by flight phase (what specification applies where), the threads file organizes by function (what must happen to make PBN work). Six threads together constitute a complete PBN implementation.

Thread 1: Flight phase#

This thread organises PBN operations by the phase of flight in which a navigation specification is applied. Different specifications govern each phase, and the operational requirements differ:

Oceanic and remote phase#

High-altitude airspace over oceans or remote land areas with no radar surveillance. Key characteristics:

• Separation provided procedurally (longitudinal and lateral).
• ADS-C and CPDLC mandatory for PBCS compliance alongside PBN.
• Long flight segments; fuel-efficiency of route structure is critical.
• Specifications: RNAV 10 (legacy), RNP 4, RNP 2.

The principal ATM interaction is with flow management and cross-oceanic coordination. CPDLC delivers RTA (required time of arrival) constraints when slot management requires metering. ADS-C provides conformance monitoring against the agreed 4D trajectory.

Continental en-route phase#

Domestic and international ATS routes over land with radar surveillance. Key characteristics:

• Radar separation generally available; surveillance is the safety net.
• RNAV specifications dominate; sensors may include DME/DME.
• Free route airspace operations are PBN-enabled (user-defined routeing within declared airspace volumes).
• Specifications: RNAV 5 (most widespread), RNAV 2, RNAV 1.

Terminal phase (SID/STAR)#

The structured departure and arrival environment connecting the en-route network to the approach phase. Key characteristics:

• Complex geometries to deconflict traffic flows and avoid terrain/ restricted airspace.
• RNP 1 and A-RNP enable curved paths (RF legs) and tighter route spacing than legacy RNAV 1 allows.
• Capacity benefit: parallel RNAV/RNP STARs can serve simultaneous flows into a major airport.

Approach phase#

The highest-integrity phase of flight. Key characteristics:

• Obstacle clearance surfaces are the safety-critical design driver.
• RNP APCH provides the mandatory baseline at all instrument runways.
• LPV lines of minima provide ILS Category I equivalent performance using SBAS vertical guidance without installing an ILS.
• RNP AR APCH (specific authorization required) enables operations where straight-in approaches are geometrically impossible.

Thread 2: Operational approval#

Approval is the bridge between the navigation specification (the standard) and the actual operation (the flight). Two levels of approval are needed: aircraft airworthiness approval and operator operational authorization.

Airworthiness approval#

The State of Design (or its delegated authority, e.g. EASA or FAA) certifies that the aircraft's navigation system meets the technical requirements of a navigation specification. This is typically reflected in the Aircraft Flight Manual (AFM) or Aircraft Flight Manual Supplement (AFMS), listing the navigation specifications for which the aircraft is eligible.

Aircraft approved for a more stringent specification are NOT automatically approved for a less stringent one — Doc 9613 §1.2.4.3.3 explains that the less stringent specification may have functional requirements (e.g. specific path terminator types) not validated for the more capable aircraft. Each specification must be explicitly approved.

Operator operational authorization#

The State of the Operator (through its CAA) issues the operator with an operational authorization (also called operational approval) confirming that:

• The aircraft is eligible for the specification.
• The operator's operations manual covers PBN procedures.
• Crew training and checking requirements are met.
• MEL (minimum equipment list) provisions for navigation equipment are adequate.

For most PBN specifications this is a general operational authorization. For RNP AR APCH and RNP AR departures a specific (Special Authorization Required, or AR) approval from the State of Registry is mandatory.

Doc 9997 (3rd Edition 2024) is the primary guidance for the authorization process, superseding and consolidating earlier guidance.

Authorization hierarchy for AR operations#

The AR approval process adds a second layer:

1. State of Registry issues the operator with AR authority (aircraft + operator criteria both met).
2. State of the aerodrome publishes the RNP AR procedure (designed per Doc 9905 and approved by the State).
3. The operator must hold both the State of Registry AR approval and the specific procedure in its operations manual before the crew may conduct the approach.

Thread 3: GNSS and NAVAID infrastructure#

The infrastructure thread covers what must be in place in the airspace before PBN operations are possible.

GNSS service availability#

For all GNSS-based PBN operations, the State or ANSP must:

• Confirm that GNSS signal availability meets the requirements of the navigation specification for the intended operation (RAIM prediction for RNP 4/RNP APCH LNAV; SBAS availability for LPV).
• Publish GNSS availability/monitoring status in the AIP and NOTAMs.
• Establish a contingency procedure for GNSS outages (reversion to conventional navigation or suspending GPS-dependent procedures).

SBAS coverage and monitoring#

SBAS services (WAAS, EGNOS, MSAS, GAGAN, SDCM) broadcast integrity data that enables LPV approaches. States must ensure that the aerodrome is within SBAS coverage before publishing LPV minima. Annex 10 Volume I defines SBAS SARPs.

Ground-based NAVAID support#

Where GNSS primary operations are not yet established:

• DME infrastructure must be verified sufficient to support DME/DME positioning for RNAV operations (coverage checks per Doc 9613).
• VOR infrastructure for RNAV 5 must be confirmed as providing the accuracy needed. As PBN coverage expands, States plan the rationalisation (consolidation or decommissioning) of redundant conventional aids.

Navigation service monitoring#

Doc 9613 Volume II, Part A, Chapter 4 addresses navigation service monitoring: the ANSP must establish procedures to monitor the GNSS signal-in-space and ground NAVAID serviceability supporting PBN routes and procedures, and to NOTAMize outages.

Thread 4: Procedure design#

PBN procedures are designed using criteria in PANS-OPS (Doc 8168 Vols I and II). The design thread translates the navigation specification into a publishable instrument flight procedure (IFP).

Key design elements:

• Path terminator selection: TF (track to fix) is the standard leg type; CF (course to fix) for radar vectors to final; RF (radius to fix) for curved paths in A-RNP/RNP AR; DF (direct to fix) for transitions.
• Obstacle clearance surfaces (OCS): derived from the total system error budget of the specification; tighter accuracy = closer OCS = lower minima possible.
• Route spacing: RNP specifications allow analytical spacing (e.g. RNP 1 STARs spaced 3–4 NM laterally in defined conditions); RNAV 1 spacing is larger due to no OBPMA margin.
• PANS-OPS Vol II criteria: the 7th Edition (2020) updated RF leg design criteria consistent with Doc 9613 5th Edition.

For RNP AR APCH, the design criteria are in Doc 9905. Procedure designers must be specially qualified and procedures approved by the State of the aerodrome through a separate authorization process before publication.

Doc 9992 (1st Edition 2013) provides higher-level guidance to States on integrating PBN into overall airspace design, including route structure, sector design, and NAVAID infrastructure planning.

Thread 5: Charting and navigation database#

Flight crew use PBN procedures via the navigation database (navdata), not by reading the chart and manually inputting coordinates. The charting and database thread ensures integrity from procedure design to FMS execution.

Charting requirements#

Aeronautical charts for PBN procedures are published per ICAO Annex 4 (Aeronautical Charts) requirements. RNP AR APCH charts must include a note identifying the required RNP value at each segment. SBAS availability notes appear where LPV minima require SBAS. The RNAV designator (e.g. RNAV(GNSS) or RNP) must appear on the approach chart.

Navigation database (navdata)#

• Coded per ARINC 424 (avionics navigation data standard) under the PANS-OPS design criteria.
• Updated on every 28-day AIRAC cycle (Annex 15/PANS-AIM requirement).
• Databases are produced by data suppliers (Jeppesen, Lido, etc.) and distributed to operators for FMS upload.
• Errors in navdata directly affect the ability of the FMS to execute the procedure correctly. Data quality management is a PBN enabler (Doc 9613 §1.1.1.1 references Annex 15 data quality).

Thread 6: Training and competency#

PBN requires specific training for all stakeholders. Doc 9613 Chapter 3 (Stakeholder Uses of PBN) addresses this cross-disciplinary requirement.

Pilot training#

• Understanding the navigation specification in use (OBPMA alerts, contingency procedures, RAIM prediction, SBAS monitoring).
• FMS programming for PBN procedures (waypoint entry, RF leg execution, monitoring CDI/EPU display).
• Specific training for RNP AR APCH (curved approaches, missed approach with RF, go-around criteria).

Controller training#

• Understanding that PBN aircraft on RNP procedures self-navigate; unnecessary vectoring during the procedure invalidates the design.
• Knowing which procedures require ATC to issue "resume own navigation" versus those where vectoring is acceptable.
• Awareness that RNAV 1 and RNP 1 procedures look identical on radar but have different safety margins.

Procedure designer training#

• Qualification to design procedures to PANS-OPS Vol II criteria.
• Additional qualification for RNP AR design per Doc 9905.
• Familiarity with ARINC 424 coding to communicate design intent to navdata providers.

ANSP planning and AIM staff#

• Understanding PBN impact on airspace structure planning.
• AIP publication of PBN requirements (infrastructure, minima, availability notes) per PANS-AIM (Doc 10066) requirements.

References#

• Doc 9613 (PBN Manual), Volume I, Chapter 2 — Oceanic, continental en-route, terminal and approach airspace concepts and associated specifications.
• Doc 9613 (PBN Manual), Volume I, Chapter 3 — Stakeholder uses: airspace planners, procedure designers, controllers, pilots.
• Doc 9613 (PBN Manual), Volume I, Chapter 4 — PBN implementation process: planning, safety assessment, procedure design, training, publication.
• Doc 9613 (PBN Manual), Volume II, Part A, Chapter 4 — Navigation service monitoring: GNSS and NAVAID serviceability for PBN operations.
• Doc 9997 (PBN Operational Authorization Manual), Third Edition 2024 — General and specific authorization process; AR approval requirements.
• Doc 9992 (Manual on the Use of PBN in Airspace Design), First Edition 2013 — Airspace design guidance integrating navigation specifications into route structures and sectors.
• Doc 9905 (RNP AR Procedure Design Manual) — Procedure design criteria and authorization process for RNP AR APCH and departures (authoritative source — not in local library).
• Doc 8168 (PANS-OPS), Volume II, Seventh Edition 2020 — Instrument procedure design criteria for all PBN specifications including RF legs.
• Annex 15 (Aeronautical Information Services) and Doc 10066 (PANS-AIM) — AIP publication requirements for PBN procedures, infrastructure notes, AIRAC cycle.

Overview#

This file works through one complete PBN navigation specification implementation as a worked example: the RNP APCH specification flown to LPV (Localiser Performance with Vertical guidance) minima. RNP APCH is the ICAO-mandated baseline approach specification, and LPV minima represent the highest-performance line of minima available within RNP APCH — approaching ILS Category I performance without a ground-based ILS.

The example tracks the full chain: airspace requirement → specification selection → NAVAID infrastructure choice → procedure design → airworthiness approval → operator authorization → flight crew execution.

Step 1: Airspace requirement#

The State of Ruritania operates an airport (LRUR) with instrument traffic but no ILS installed. The runway is aligned toward a ridge; a conventional straight-in NDB approach has a minimum descent altitude (MDA) of 700 ft AGL and handles only Category A/B aircraft. The State wants:

• A lower decision altitude (ideally 200 ft DA) for transport category aircraft.
• A published vertical profile (APV) to eliminate level-off at MDA.
• No new ground aid investment.

The operational requirement points to RNP APCH with LPV minima: it provides APV Type I minima (DA from ~200 ft AGL) using SBAS, requires no new ground infrastructure if SBAS coverage exists, and is within the normal RNP APCH authorization process (no specific AR approval needed).

Step 2: Navigation specification selection#

The State confirms that EGNOS (the European SBAS) provides APV-I service at LRUR. LPV minima under RNP APCH require:

• Aircraft equipped with an SBAS receiver capable of LPV operations.
• SBAS service availability sufficient for the operation (availability study per Doc 9613 guidance).
• The SBAS system certified to Annex 10 Volume I standards.

The State selects the RNP APCH navigation specification from Doc 9613 Volume II, Part C, Chapter 5, Section B (LP and LPV minima). The specification defines:

• Lateral accuracy: 40 m (95%) in the final approach segment (this is expressed as angular performance consistent with the LPV glide path structure).
• Vertical accuracy: 4 m (95%) for the vertical guidance channel.
• OBPMA: mandatory — the aircraft's SBAS receiver continuously monitors signal integrity and removes the satellite from the solution if the protection level exceeds the alert limit.
• Path terminator: TF legs throughout with a defined fictitious threshold point (FTP) as the approach reference datum.

Step 3: Procedure design#

The State's procedure design team (qualified to PANS-OPS criteria) design the approach:

1. Reference datum: The FTP is placed at the runway threshold at a height consistent with the glide path angle (typically 3 degrees).
2. Glide path angle: 3.0 degrees standard; PANS-OPS allows steeper angles in terrain-constrained environments (up to ~6 degrees for approach Category A/B; special criteria apply for steeper).
3. Obstacle clearance: Computed using the OCS (obstacle clearance surface) appropriate for RNP APCH final approach. The OCS slope accounts for the angular accuracy budget of the SBAS lateral channel.
4. Missed approach: Published as a conventional go-around procedure (heading/altitude instruction to a fix); no RF leg required for standard RNP APCH.
5. Lines of minima published: The same procedure chart will list all applicable lines of minima: LNAV, LNAV/VNAV and LPV. Aircraft that cannot use LPV (no SBAS, or avionics limitation) fly to LNAV or LNAV/VNAV minima.

The procedure is coded in ARINC 424 format and submitted to the navigation data supplier for inclusion in the AIRAC database cycle.

Step 4: NAVAID infrastructure confirmation#

Before LPV minima can be published, the State must confirm SBAS service availability at LRUR:

• EGNOS Service Level: APV-I service must be confirmed available for the percentage of time required (typically greater than 99%).
• The AIP entry includes a note confirming SBAS is required and which SBAS system (EGNOS in this example).
• The ANSP publishes RAIM/SBAS NOTAMs when GNSS satellite outages may degrade availability below approach minima.

Step 5: Airworthiness approval#

The airline operating into LRUR checks its aircraft AFM/AFMS for LPV eligibility. For LPV operations, the aircraft must have:

• An SBAS receiver certified to TSO-C145()/C146() (USA) or ETSO-C145()/C146() (EASA).
• An FMS or CDI capable of displaying LPV deviation.
• The AFM statement listing the navigation specification (RNP APCH to LPV minima) as approved.

If the aircraft holds only LNAV approval (basic GNSS receiver without SBAS), it may fly LNAV or LNAV/VNAV minima but not LPV.

Step 6: Operator operational authorization#

The airline's CAA issues an operational authorization confirming:

1. Aircraft eligibility (SBAS-capable FMS, LPV-certified).
2. Operations manual procedures for RNP APCH including:
   • Pre-flight RAIM/SBAS availability check for the destination.
   • Crew action if SBAS integrity alert occurs during approach.
   • Crew action if EPU exceeds the approach protection level.
   • Stabilised approach criteria (no RNP APCH is flown without an FPA-based continuous descent final approach, CDFA).
3. Crew training and simulator checking requirements met.
4. MEL provisions for the SBAS receiver.

No specific AR approval is required for standard RNP APCH (including LPV). AR approval is only required for RNP AR APCH.

Step 7: Flight crew execution#

On the day of the flight, the crew:

1. Pre-flight: Check NOTAM for GNSS/SBAS status at LRUR. Run RAIM/ SBAS prediction if required by the operator's OM. Confirm LPV minima in the instrument approach chart.
2. FMS programming: Select the RNAV(GNSS) RWY XX approach from the FMS database. The FMS automatically loads the coding including all waypoints, leg types, and the glide path angle. Select LPV as the approach type if avionics require it.
3. During the approach: The FMS computes and displays EPU (or HAL/ VAL — horizontal/vertical alert limits). If the protection level exceeds the alert limit, the SBAS receiver or FMS generates an annunciation; the crew reverts to LNAV minima or executes a missed approach. The navigation system is the crew's primary alert mechanism — this is OBPMA in practice.
4. Decision altitude: With LPV minima, the DA may be published as 200 ft AGL (subject to obstacle clearance). The crew uses flight path angle reference on the PFD to fly a continuous descent to the DA.
5. Missed approach: If not visual at DA, go-around per published procedure (heading, climb altitude, fix).

Key architectural insight#

This worked example illustrates the fundamental PBN architecture in miniature: the specification (RNP APCH to LPV) sets the rules; the infrastructure (EGNOS SBAS) provides the positioning; the application (the LRUR approach procedure) is the specific use case. Change the infrastructure (WAAS instead of EGNOS) and the application looks the same to the crew. Change the specification (RNP AR APCH instead of RNP APCH) and the procedure can have curved paths and AR-only minima. The components are interchangeable within the bounds of the specification.

References#

• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 5 — RNP APCH specification; LNAV, LNAV/VNAV, LP and LPV lines of minima.
• Doc 9613 (PBN Manual), Volume II, Part C, Chapter 5, Section B — LPV and LP minima using SBAS; accuracy, continuity and availability requirements.
• Doc 9997 (PBN Operational Authorization Manual), Third Edition 2024 — Operator authorization process for RNP APCH including LPV operations.
• Doc 8168 (PANS-OPS), Volume II, Seventh Edition 2020 — Procedure design criteria for RNP APCH; obstacle clearance surfaces; CDFA requirements.
• Annex 10 (Aeronautical Telecommunications), Volume I — SBAS SARPs; EGNOS, WAAS, MSAS, GAGAN standards.
• Annex 6 Part I (Operation of Aircraft — International Commercial Air Transport), §7.3 — Instrument navigation equipment requirements for PBN operations.
• Doc 9613 (PBN Manual), Volume I, Chapter 3, §3.2 — Procedure designer uses of PBN including selection of navigation specification and obstacle clearance.

What must be in place#

PBN operations require a coherent set of enablers across GNSS/CNS infrastructure, airworthiness, operations approval, procedure design, data quality, training, and institutional frameworks. A weakness in any enabler can prevent or degrade PBN operations regardless of the maturity of the others.

Doc 9613 Vol I §1.1.3 frames this: "PBN is one of several enablers of an airspace concept. Communications, air traffic services (ATS) surveillance and air traffic management (ATM) are also essential elements of an airspace concept." PBN is itself an enabler for ATM; it has its own enabling chain.

GNSS infrastructure enablers#

GNSS is the primary positioning sensor for the vast majority of PBN operations. The following must all be in place:

Signal-in-space (SIS) availability#

The GNSS constellation must provide adequate satellite geometry and signal quality for the intended operation. Each navigation specification defines a continuity and availability requirement:

• For RNP APCH LNAV: GPS with RAIM prediction confirming availability.
• For RNP APCH LPV: SBAS signal in the APV-I or better service level.
• For RNP 4 oceanic: GPS with RAIM prediction or ADS-C conformance.

States must establish GNSS availability monitoring and publish outage NOTAMs through the ANSP.

SBAS coverage for approach#

LPV operations require that an SBAS system (EGNOS, WAAS, MSAS, GAGAN, or another Annex 10-certified system) provides APV-I (or better) service at the aerodrome. Where SBAS coverage is marginal or intermittent, LPV minima cannot be published. LNAV/VNAV (baro-VNAV) or LNAV-only minima remain available as fallback.

Dual-frequency multi-constellation (DFMC)#

The DFMC evolution (Doc 9613 §1.6.2) will enable next-generation PBN operations with improved availability in challenging environments and reduced vulnerability to ionospheric disturbances. States planning future approach operations to LPV-200 equivalents should track DFMC SBAS availability in their region.

GNSS contingency planning#

Doc 9613 §1.6.1.3 states: "As more reliance is placed on GNSS, airspace concepts will increasingly need to ensure the coherent integration of communications, navigation and ATS surveillance enablers. Safety cases should consider the impact of losing GNSS in terms of CNS."

Enablers for GNSS contingency:

• Published reversion procedures (e.g. ILS, DME/DME) when GNSS is lost.
• NOTAM system with timely promulgation of RAIM holes and SBAS outages.
• Controller training to manage reversion events.
• DME infrastructure maintained as a contingency positioning source in high-density terminal areas.

Ground-based NAVAID enablers#

Where ground-based NAVAIDs are the primary or backup positioning source:

DME infrastructure#

For RNAV 5, RNAV 1 and RNAV 2 operations using DME/DME, adequate coverage requires at least two simultaneous DME signals within line-of- sight at sufficient geometry. States must conduct DME/DME coverage analysis and publish the results in the AIP (listing which routes require GNSS versus which can use DME/DME).

VOR serviceability#

For RNAV 5 operations using VOR/DME, the VOR must meet Annex 10 accuracy standards. VOR/DME positioning is generally less accurate than GNSS or DME/DME for RNAV; RNAV 5 is the typical limit for VOR/DME-based positioning.

NAVAID rationalisation planning#

As PBN operations mature, States face the question of which conventional aids to retain, consolidate or decommission. Doc 9613 §1.1.2(a) notes that PBN "reduces the need to maintain sensor-specific routes and procedures, and their associated costs." Rationalisation planning must:

• Confirm GNSS coverage is adequate before removing a ground aid.
• Assess the impact on contingency navigation.
• Coordinate with neighbouring States where cross-border procedures reference the aid.
• Publish the rationalisation plan with sufficient notice for operators to update databases.

Airworthiness enablers#

No PBN operation is possible without aircraft that meet the relevant airworthiness approval.

Aircraft flight manual (AFM/AFMS)#

The AFM or its supplement must list the navigation specifications for which the aircraft is approved. This approval is issued by the State of Design or its designee (EASA, FAA, etc.) and flows from the type certificate (TC) or supplemental type certificate (STC).

Standards compliance#

RNAV/RNP avionics must meet applicable Technical Standard Orders:

• FAA TSO-C129()/TSO-C196() for GPS sensors.
• FAA TSO-C115()/ETSO-C115() for FMS with RNAV capability.
• FAA TSO-C145()/C146()/ETSO equivalents for SBAS receivers.
• RTCA DO-236()/EUROCAE ED-75() for A-RNP.

Approved avionics lists are maintained in Volume II, Attachment E of Doc 9613.

MEL provisions#

The operator's Minimum Equipment List must specify the dispatch requirements for the navigation equipment. For example: "GNSS receiver must be operative for RNP APCH; baro-VNAV must be operative for LNAV/VNAV minima; SBAS receiver must be operative for LPV."

Regulatory and authorization enablers#

State regulatory framework#

The State must publish the navigation specifications applicable in its airspace in the AIP, together with infrastructure requirements and any additional conditions (e.g. specific approved sensors). Doc 9992 provides guidance on this publication.

Operational authorization issuance#

The State of the Operator must have a regulatory basis and process for issuing PBN operational authorizations (general for most specs; specific AR approval for RNP AR APCH/departures). Regulatory framework typically references Doc 9997 as the standard for the authorization process.

Doc 9997 framework (3rd Edition 2024)#

The Operational Authorization Manual was renamed (from "Operational Approval Manual") in its 3rd Edition (2024), reflecting the shift in ICAO terminology to "authorization" for the general approval process. It provides:

• General and specific authorization categories.
• Safety risk management guidance (aligned with Annex 19 SMS principles).
• Worked examples of assessment checklists.
• Guidance for Continuing Airworthiness requirements in the PBN context.

Navigation database enablers#

ARINC 424 coding#

Every PBN procedure must be coded in ARINC 424 format before it can be loaded into an FMS. The coding must accurately represent the procedure design intent: path terminators, waypoint coordinates, altitudes, speeds, and RF leg centre-points and radii.

Errors in ARINC 424 coding cause the FMS to execute a different path from the designed procedure. PANS-AIM (Doc 10066) and Annex 15 requirements for data quality apply to the AIM publication chain from which navdata suppliers derive their databases.

AIRAC cycle compliance#

Procedure changes must be published on the AIRAC cycle (28-day cycle with effective date on a specific Thursday). Operators update FMS databases on each AIRAC cycle. Changes outside the AIRAC cycle (unless urgent safety-driven) create a period where the FMS database may differ from the published procedure.

Data quality management#

Annex 15 §3.2 and PANS-AIM require that aeronautical data meet accuracy, resolution, integrity and traceability requirements. PBN is explicitly cited in Doc 9613 §1.1.1.1 as requiring compliance with the world geodetic system and Annex 15 data quality. Poor data quality can cause systematic FMS positioning errors.

Training enablers#

Pilot training#

Crew Resource Management (CRM) includes management of FMS alerting during OBPMA events. Line-Oriented Flight Training (LOFT) should include scenarios where RAIM or SBAS alerts occur during approach. Type Rating training must include FMS programming for PBN departure and arrival.

Controller training#

ATC training must include:

• Understanding that RNP procedures must not be interrupted by unnecessary vectoring once the crew has been cleared for the procedure.
• Knowing which PBN procedures are "non-interruptible" (e.g. RNP AR APCH may require that once established on the final approach course, no changes are issued unless the crew requests).
• Procedures for managing mixed-equipage environments (some aircraft on RNP procedures, others on conventional routes simultaneously).

Procedure designer qualification#

Doc 9613 Chapter 3 and PANS-OPS require that instrument procedure designers be formally trained and qualified for the criteria being applied. RNP AR design requires additional qualification. Training is typically delivered through the ICAO TRAINAIR PLUS network and regional procedure design courses.

Institutional enablers#

Regional coordination#

PBN implementation is most effective when coordinated regionally. ICAO regional planning groups (APANPIRG for APAC, MIDANPIRG for MID, etc.) publish regional implementation plans and track progress. The APAC Seamless ATM Plan explicitly addresses PBN implementation milestones for the region.

Technical assistance#

ICAO's No Country Left Behind initiative provides technical and financial assistance to States that lack the human resources or infrastructure to implement PBN independently. ICAO regional offices coordinate assistance with IATA, CANSO, ICAO TRAINAIR, and bilateral partners.

References#

• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.6.1 — GNSS reliance and the need for coherent CNS integration in airspace concepts.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.6.2 — Dual-frequency multi-constellation GNSS evolution and transition.
• Doc 9613 (PBN Manual), Volume I, Chapter 3, §3.2.3 — Infrastructure planning: NAVAID infrastructure evolution and PBN implementation.
• Doc 9613 (PBN Manual), Volume II, Attachment E — Document references for airworthiness approval: TSO, AMC, AC, RTCA DO, EUROCAE ED standards.
• Doc 9997 (PBN Operational Authorization Manual), Third Edition 2024 — Authorization process; safety risk management; MEL and AFM requirements.
• Doc 9992 (Manual on the Use of PBN in Airspace Design), First Edition 2013 — State airspace design process integrating PBN infrastructure, procedure design and publication.
• Annex 15 (Aeronautical Information Services) and Doc 10066 (PANS-AIM) — Data quality requirements for aeronautical data and PBN procedure publication.
• Doc 8168 (PANS-OPS), Volume II — Procedure design criteria; qualification of instrument procedure designers.

The performance lens#

PBN was designed from the outset to be measurable. The phrase "performance-based" in the name commits every element of PBN — from the navigation specification to the airspace concept — to defining what performance is required and how it will be verified. This connects PBN directly to the ICAO Key Performance Areas (KPAs) from Doc 9854 and the KPI measurement framework from Doc 9883.

For PBN, the primary performance question is: does the navigation specification and its implementation deliver the operational benefit that justified the investment?

Performance objectives by navigation application#

Oceanic and remote PBN (RNP 4 / RNP 2)#

Objective: Reduce lateral separation minima in oceanic/remote airspace, enabling more direct routing and preferred flight levels.

• RNP 4 with ADS-C and CPDLC: 50 NM lateral separation (versus 100 NM with older procedural or RNAV 10 operations).
• This directly reduces average track-mile distance per flight, cutting fuel burn and CO2.
• Predictability benefit: ADS-C conformance monitoring means deviations are detected earlier, reducing late resequencing.

Primary KPAs: Flight efficiency, Environment, Capacity.

Continental en-route PBN (RNAV 5 / RNAV 1)#

Objective: Enable more direct routing, flexible use of airspace, and free route airspace by removing the requirement to overfly specific ground aids.

• Straight-line SID/STAR procedures reduce track miles versus conventional VOR-based routes.
• Free Route Airspace (FRA) is a PBN-enabled operation.
• Route spacing analysis rather than empirical margins.

Primary KPAs: Flight efficiency, Capacity, Cost-effectiveness.

Terminal PBN (RNP 1 / A-RNP STARs)#

Objective: Improve arrival flow predictability, enable CDO/CCO from higher altitudes, reduce controller vectoring workload.

• Published RNP 1 STARs allow capacity planning based on known occupancy times rather than variable vectoring.
• A-RNP with RF legs enables optimized tracks around terrain and noise-sensitive areas.
• Reduced vectoring improves controller workload and increases STAR throughput.

Primary KPAs: Capacity, Predictability, Flight efficiency, Environment.

Approach PBN (RNP APCH / RNP AR APCH)#

Objective: Provide instrument approach capability at all runway ends (including those with no existing ILS), lower decision altitudes, and access to terrain-constrained airports.

• RNP APCH LPV provides Cat I ILS-equivalent minima without ground-based ILS.
• RNP AR APCH opens access to airports otherwise requiring VMC (visual meteorological conditions) operations.
• Baro-VNAV (LNAV/VNAV) provides APV operations at airports without SBAS coverage.

Primary KPAs: Safety, Access and equity, Capacity (diversion reduction).

KPA contribution by navigation specification family#

The following matrix scores each KPA by its principal benefit horizon across the four PBN specification families. Scale: 1 = some benefit, 2 = clear benefit, 3 = primary driver.

Key Performance Indicators (KPIs)#

Safety KPIs#

• Navigation accuracy exceedance rate: percentage of flights where estimated position uncertainty (EPU) exceeds the RNP value — should approach zero for properly authorized operations.
• OBPMA alert frequency: number of RNP/SBAS integrity alerts per 1,000 operations; high rates indicate infrastructure or avionics issues.
• Approach runway excursion events attributable to navigation failures.
• Loss of separation events linked to PBN route violations.

Capacity KPIs#

• STAR occupancy time: average time from STAR entry to threshold; lower and more consistent than legacy vectoring with published RNP 1 STARs.
• Runway acceptance rate (RAR): movements per hour sustained during peak periods; RNP APCH reduces weather-driven capacity losses.
• Diversion rate: proportion of flights diverting due to weather or approach unavailability; LPV availability reduces diversions.

Flight efficiency KPIs#

• KEP (Key indicator of En-route efficiency relative to the last filed flight plan): percentage difference from great-circle distance.
• Track mile reduction: average reduction in track distance achieved by publishing direct SID/STAR routes versus VOR-based paths.
• Vertical efficiency: conformance with CDO/CCO profiles using RNAV/RNP STAR procedures.

Environmental KPIs#

• Fuel burn per flight: reduction from shorter track miles (oceanic) and CDO/CCO conformance (terminal).
• CO2 per movement: measurable reduction when RNP APCH enables CDO to touchdown versus level-off at MDA.
• Noise contour area: at airports where RNP AR APCH curves away from noise-sensitive areas; measurable reduction in noise-exposed population.

Access KPIs#

• Percentage of instrument runways with RNP APCH published: the primary ICAO mandate tracking metric (Assembly Resolution A37-11 target: 100% of instrument runways).
• Number of previously VMC-only airports upgraded to instrument approach capability through RNP APCH or RNP AR APCH.
• Reduction in missed approach rate due to higher minima.

Interoperability KPIs#

• Global PBN implementation rate: percentage of ICAO Contracting States with PBN programmes in place (tracked by ICAO Universal Safety Oversight Audit Programme — USOAP and State Action Plans).
• Cross-border PBN continuity: number of cross-border PBN route pairs where both States have published matching navigation specifications.

How performance is reported#

Globally: ICAO tracks PBN implementation through Universal Safety Oversight Audit Programme (USOAP) results and State Action Plans. Progress toward the Assembly Resolution A37-11 RNP APCH mandate is reported in ICAO Air Navigation Commission reports.

Regionally:

• APAC: APANPIRG performance framework; Seamless ATM Plan PBN milestones.
• EUR: EUROCONTROL Performance Review Body (PRB) reports; LSSIP (Local Single Sky Implementation plan) tracks PBN deployment.
• MID: MIDANPIRG and MID ANS Strategy PBN metrics.
• NAT: NAT SPG (Separation and Airspace Group) tracks RNP 4 and PBCS implementation.

State level: State Safety Programme (SSP) reports and State PBN Implementation Plans — typically submitted to ICAO via the regional office.

PBN and the ASBU performance framework#

Within the GANP ASBU framework, PBN-related performance is tracked through two threads:

• APTA (Optimization of Approach Procedures including Vertical Guidance) — tracks RNP APCH LPV/LNAV/VNAV deployment at instrument runways; the primary ASBU-level KPI is percentage of instrument runways with APV procedures published.
• NAVS (Navigation Services) — tracks infrastructure evolution (DFMC GNSS, SBAS coverage extension); KPI is percentage of airspace hours where GNSS-based PBN is the primary means of navigation.

The GANP Portal carries the performance objective catalogue linked to these threads, allowing planners to align national PBN programmes with ASBU block milestones.

References#

• Doc 9854 (Global ATM Operational Concept), Chapter 2 — Key Performance Areas (KPAs) as the eleven dimensions of ATM performance.
• Doc 9883 (Manual on Global Performance of the Air Navigation System) — KPI catalogue and performance measurement methodology.
• Doc 9613 (PBN Manual), Volume I, Chapter 3, §3.1 — Overview of stakeholder performance benefits from PBN.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.1.2 — Listed benefits of PBN: efficiency, cost reduction, airspace improvement.
• Doc 9750 (GANP), ASBU Threads APTA and NAVS — Performance objectives linked to PBN approach and navigation service modernization (authoritative source — not in local library; see https://ganpportal.icao.int/).
• Doc 9750 (GANP), Performance Objective catalogue — Approach procedure performance objectives and KPIs (authoritative source — not in local library).

Timeline#

The following table provides a year-keyed history of PBN, from the origins of the Required Navigation Performance concept through the current 5th Edition and ongoing DFMC evolution.

Milestone themes#

1983-2007: From RNP to harmonization need#

The original RNP concept was elegant but spawned divergent implementations. North Atlantic RNP 10 operations, US RNAV approvals, European P-RNAV, and Australian BRNAV/PRNAV operations all used different criteria for nominally similar performance levels. The aviation community recognized that without a globally harmonized framework, cross-border operations would require multiple approvals for equivalent capability.

2008: The PBN concept edition#

The third edition of Doc 9613 (2008) is the watershed document. It replaced the single "RNP value" concept with the navigation specification framework: a named specification defines accuracy, integrity, functionality, and sensor choices in a self-contained unit. This structure — with two families (RNAV and RNP) and a per-phase catalogue — has remained stable through the fourth and fifth editions.

2010-2016: The mandate era#

Assembly Resolution A37-11 was the most consequential PBN policy act. By establishing a 2016 deadline, it forced States to create national PBN implementation plans, allocate budget, train designers, and begin publishing procedures. The mandate was not fully met by 2016 in many developing States, but the direction was set irreversibly.

2013-2023: Specification expansion#

The fourth edition (2013) added A-RNP and RNP 2 — the two specifications that enable the most flexible terminal and continental operations. The fifth edition (2023) refined A-RNP, clarified helicopter-only RNP 0.3, and opened RF legs to wider use beyond RNP AR APCH. Each edition reflects the maturation of avionics capability and operator experience.

2024 onward: DFMC and next-generation precision#

The DFMC evolution represents the next performance step. With four GNSS constellations providing dual-frequency signals, SBAS approaches will achieve higher availability and resist ionospheric disturbances better than current single-frequency L1-only operations. This enables approach operations in geographic areas (high latitude, equatorial) where current SBAS availability is marginal.

References#

• Doc 9613 (PBN Manual), Foreword — Development history of the PBN concept from FANS RNPC through 5th Edition 2023.
• Doc 9613 (PBN Manual), Volume I, Chapter 1, §1.6.2 — DFMC GNSS evolution and future PBN development directions.
• Doc 9750 (GANP), 7th Edition 2026 — ASBU Block milestones including NAVS-B2 for multi-constellation multi-frequency navigation (authoritative source — not in local library; see https://ganpportal.icao.int/).
• ICAO Assembly Resolution A37-11 (2010) — Global PBN mandate; 2016 target for en-route/terminal PBN and RNP APCH at all instrument runways (authoritative source — not in local library).
• ICAO Assembly Resolution A38-12 (2013) — Reinforcement of PBN mandate; technical assistance for developing States.
• ICAO Assembly Resolution A40-11 (2019) — PBN progress review; NAVAID rationalisation encouragement (authoritative source — not in local library).
• Doc 9992 (Manual on the Use of PBN in Airspace Design), First Edition 2013 — Guidance supporting the mandate implementation period.
• Doc 9997 (PBN Operational Authorization Manual), Third Edition 2024 — Current authorization standard aligned with 5th Edition Doc 9613.

Primary ICAO Documents#

• Doc 9613 (PBN Manual), Volume I (Concept and Implementation Guidance), Fifth Edition 2023 — The authoritative ICAO reference for PBN concept, navigation specification framework, stakeholder roles, and implementation guidance.
• Doc 9613 (PBN Manual), Volume II (Implementing RNAV and RNP Operations), Fifth Edition 2023 — Navigation specifications for all ten RNAV and RNP specifications organized by flight phase; airworthiness and operational authorization requirements.
• Doc 9997 (PBN Operational Authorization Manual), Third Edition 2024 — Operator authorization process for PBN operations; general and AR-specific authorization; safety risk management; MEL and AFM requirements.
• Doc 9992 (Manual on the Use of PBN in Airspace Design), First Edition 2013 — Guidance for States and ANSPs on translating PBN concepts into airspace design, route structure, procedure design rationale, and NAVAID infrastructure planning.
• Doc 9905 (RNP AR Procedure Design Manual) — Procedure design criteria for RNP AR APCH and RNP AR departure procedures; safety assessment requirements (authoritative source — not in local library).

ICAO PANS and Procedures#

• Doc 8168 (PANS-OPS), Volume I (Flight Procedures), Sixth Edition 2018 — Flight crew procedures for instrument approaches including PBN approaches; CDFA requirements; missed approach execution.
• Doc 8168 (PANS-OPS), Volume II (Construction of Visual and Instrument Flight Procedures), Seventh Edition 2020 — Instrument procedure design criteria for all PBN specifications; RF leg design criteria updated consistent with Doc 9613 5th Edition; obstacle clearance surface definitions.
• Doc 10066 (PANS-AIM), applicable 2024 — AIP publication requirements for PBN procedures; infrastructure notes; AIRAC cycle requirements for procedure updates.

ICAO Annexes#

• Annex 6 Part I (Operation of Aircraft — International Commercial Air Transport), Chapter 7, §7.3 — Instrument navigation equipment requirements for operations where PBN navigation specifications are prescribed.
• Annex 6 Part II (Operation of Aircraft — International General Aviation Aeroplanes), §2.5.2.2 — Equipment and documentation requirements when a PBN navigation specification has been prescribed.
• Annex 6 Part II, §2.5.2.5 — Specific approval requirement from State of Registry for AR navigation specifications.
• Annex 6 Part III (International Operations — Helicopters) — PBN requirements for helicopter operations including RNP 0.3.
• Annex 10 (Aeronautical Telecommunications), Volume I (Radio Navigation Aids) — GNSS SARPs: GPS, GLONASS, SBAS (WAAS, EGNOS, MSAS, GAGAN), GBAS standards; the normative source for NAVAID infrastructure requirements.
• Annex 15 (Aeronautical Information Services) — Data quality requirements for aeronautical data including PBN procedure coordinates and charts.

ICAO Assembly Resolutions#

• ICAO Assembly Resolution A37-11 (37th Session, 2010) — Global PBN mandate; 2016 target for en-route, terminal and approach PBN implementation at all instrument runways worldwide (authoritative source — not in local library).
• ICAO Assembly Resolution A38-12 (38th Session, 2013) — Reinforcement of PBN mandate; technical assistance for developing States; progress review.
• ICAO Assembly Resolution A40-11 (40th Session, 2019) — PBN implementation progress review; NAVAID rationalisation encouragement; RNP AR APCH expansion.

GANP and ASBU References#

• Doc 9750 (GANP), 7th Edition 2026 — ASBU threads APTA (Optimization of Approach Procedures) and NAVS (Navigation Services); PBN as the navigation foundation for Blocks 0-3 (authoritative source — not in local library; see https://ganpportal.icao.int/).

Supporting ICAO Documents#

• Doc 9849 (Global Navigation Satellite System (GNSS) Manual), Second Edition 2005 — Supplementary guidance on implementing GNSS to support PBN.
• Doc 9883 (Manual on Global Performance of the Air Navigation System) — KPI catalogue and performance measurement methodology; KPAs applicable to PBN performance evaluation.
• Doc 9854 (Global ATM Operational Concept), First Edition 2005 — ATM concept framework within which PBN is an enabling element; KPA definitions.

External Authoritative Sources#

• https://www.icao.int/safety/pbn/Pages/default.aspx - ICAO PBN Programme page; State implementation dashboards and programme status
• https://store.icao.int/products/performance-based-navigation-pbn-manual-doc-9613 - Doc 9613 (PBN Manual, 5th Edition 2023) official ICAO store
• https://store.icao.int/products/pbn-operational-authorization-manual-doc-9997 - Doc 9997 (3rd Edition 2024) official ICAO store
• https://www.icao.int/safety/pbn/Documents/Doc9992.pdf - Doc 9992 (Airspace Design Manual, 1st Edition 2013) official ICAO PDF
• https://www.eurocontrol.int/concept/performance-based-navigation - EUROCONTROL PBN concept overview and EUR implementation status
• https://ganpportal.icao.int/ - ICAO GANP Portal; APTA and NAVS thread performance objectives and module details
• https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap1_section_2.html - FAA AIM Chapter 1 Section 2: RNAV and RNP operational concepts (authoritative source — not in local library)
• https://www.easa.europa.eu/en/document-library/acceptable-means-of-compliance-and-guidance-material/cs-rnav-operations - EASA CS and AMC for RNAV/RNP operations (authoritative source — not in local library)