Performance Based Navigation

Aramco

Agenda

We will first look at the evolution of navigation approvals. Next we will look at navigation specifications in detail. Finally we will look implementation of PBN worldwide.

1. Overview of CNS-ATM1. Overview of CNS-ATM

2. FANS to RNP2. FANS to RNP

3. RNP to PBN3. RNP to PBN

4. PBN Concepts4. PBN Concepts

5. Navigation Approvals5. Navigation Approvals

6. PBN Operational Summary6. PBN Operational Summary

Objectives

Understand the evolution of navigation approvalsKnow what documents to use for further studyUnderstand how airspace capabilities work together to create navigation specificationsHave a feel for PBN implementation timeline

By the end of this session you will understand how the pieces of the CNS/ATM work together to create an airspace. Also you will understand the importance of the navigation specifications.

Navigation Approvals

Along with the evolution of RNP allowing navigation based on airplane systems came the evolution of navigation approvals to ensure compliance.

RNP

Those were the days

The Old Days

Prior to RNAV operations, there was no requirement for Operational Approvals; also referred to as Navigation Approvals by some States. Aircrews had to be qualified for IFR flight, and aircraft had to be equipped with navigation equipment corresponding to ground-based navigation aids defining ATS routes.

MNPS

The First One

The first Operational Approval resulted from implementing the Minimum Navigation Performance Specification (MNPS). The guidance material was first published in 1979 and was primarily for the information of pilots and dispatchers planning and conducting operations in the North Atlantic (NAT) airspace.

MNPS not defined by Performance

While aircraft had to demonstrate Total System Error (TSE) navigation accuracy of ±12.6 NM 95% of the total flying time, MNPS was never referred to as RNP or RNAV 12.6.

Therefore the first Operational Approval for ‘Required Navigation Performance’ was for RNP 10, written by the FAA in 1996.

First RNP Operational Approval

RNP 10 over the Oceans

On April 23, 1998 Anchorage Air Route Traffic Control Center (ARTCC) implemented lateral separation standards within the NOPAC (North Pacific) route structure from FL 310 to FL 390 to all aircraft that are RNP 10 approved

On the same day, Australia and New Zealand implemented RNP in the Tasman Sea airspace

As of Dec. 3, 1998 a 50 nm lateral separation standard was applied in the Central Pacific (CENPAC) (Pacific Organized Track System only) to all aircraft that are RNP 10 approved

The 50 nm separation that RNP 10 standards allowed became popular in 1998.

BRNAV

At about this time, Basic Area Navigation (B-RNAV) was developed by the European Civil Aviation Conference (ECAC), and became mandatory on April 23, 1998 as the primary means of navigation in all ECAC en-route airspace.

RVSM Approval

Following B-RNAV was the RVSM Operational Approval, effective in January 2002, which prescribed both airworthiness requirements, to ensure aircraft height-keeping performance in accordance with the RVSM Minimum Aviation System Performance Standards, and also crew operating procedures.

Approval Basics

MNPSRNP 10BRNAVRVSM

Airworthiness Approval (aircraft eligibility-equipment)

Operational Approval (company operating procedures)based on operating procedures, flight crew training, and control of the navigation database

process (where required).

Each of these require both an equipment and operational approval. The Airworthiness and Operational Approval are obtained in accordance with national operating rules of the State of Operator/Registry for individual aircraft type group/equipment. Next let’s look at Surveillance approvals.

Surveillance ApprovalsCPDLC requires Ops spec approval

Datalink communications require operations specifications approval.

Standardizing the Approvals - PBN

Transition to PBN introduces the potential for aircraft to demonstrate requirements compliance through a mix of capabilities, rather than only specific equipment. That is why the approval is based on total ‘performance’ and is not tied to any specific navigation equipment.

PBN Facilitates Operational Approval

PBN facilitates the operational approval process for operators by providing a limited set of Navigation Specifications intended for global use. A Navigation Specification is a set of aircraft and aircrew requirements needed to support a navigation application within a defined airspace concept.

RNAV 5RNP 1RNAV (RNP) 10…

A navigation specification does not in itself constitute regulatory guidance material, and consequently an Operational Approval is NOT GRANTED against the PBN navigation specification, but the applicable regulatory material of the State of Operator/Registry corresponding to a particular Navigation Specification.

Multiple Approvals are Required

If an aircraft and crew are certified for a particular navigation specification, it does not imply automatic qualification for a navigation specification requiring less accuracy. Similarly, if qualified or certified for an RNP specification, it does not imply automatic qualification for RNAV specifications.

Always Check the Details

The Nav Spec is based on that country’s available infrastructure (navaids)

What you need to fly an RNAV 1 route, for example may vary

Be careful, navigation specifications with the same designator may vary between States as they depend on the State’s NAVAID infrastructure.

PBN Approval ReviewPBN requires the use of an on-board Area Navigation system;

PBN creates requirements for airworthiness certification and operational approval to use area navigation systems in airspace implementations;

The area navigation system’s functionality as well as its navigation accuracy in the Navigation aid environment of the subject airspace must conform to the requirements stipulated in the relevant ICAO navigation specification.

For PBN both the aircraft and air crew must be qualified against the particular Navigation Specifications required for operation in the airspace. Note we have been talking about approval, not the requirements for flight in a particular airspace.

The Airspace Concept

Under PBN, the airspace concept uses the capabilities available in the airspace to define navigation specifications. The capabilities come from each of the Communications, Navigation and Surveillance possibilities. This combination identifies our current airspace requirements during a flight. Before we look at those pieces, let’s look at the ATM.

Airspace Concept

Communications Surveillance ATMNavigation

Airspace Concept

Communications Navigation ATMSurveillance

• A close co-operation of ATS, crews and airline operational centers, is expected to be reached through data communications, and automated sharing of real-time information. (e.g. ADS-B)

• CPDLC, ADS and AOC/ATC inter-facility link are some of the tools used to support new ATM methods such as Collaborative Decision Making (CDM).• The aim of CDM is to enable the crews, controllers and operations involved in

ATM system, to improve mutual knowledge of the forecast/current situations, of each other constraints, preferences and capabilities, so as to resolve potential problems.

ATM

Under this term is grouped a large set of methods to improve the management of all the parts of the air traffic, e.g. traffic flow management, strategic (long term) and tactical (short term) control or air traffic services.

ATM Example

The ATM facilitates the operations in the airspace. An example is the airport collaborative decision making (A-CDM). The A-CDM optimizes slot times and minimizes delays, among other things. Datalink operations for requests such as engine start-up are possible. Now let’s get back to how the capabilities in a given airspace create navigation specifications for us.

Airspace Concept

Communications Navigation ATMSurveillance

RTF (Voice)RTF + Datalink (CPDLC) …

Communication Capabilities in the Airspace

These are communication examples.

Airspace Concept

Communications Navigation ATMSurveillance

ProceduralATS Surveillance (Positive)ADS CADS B

Surveillance Capabilities in the Airspace

Different types of surveillance may be found. Wherever radar coverage is possible, SSR modes A and C are still used. Mode S is used in such areas where traffic densities are high enough to warrant it.

PBN Capabilities in the Airspace

PBN has three components that are used to identify an airspace: the NAVAID infrastructure, the navigation specification and the navigation application.

Navigation

Application

NAVAID Infrastruct

ure

Navigation Specificati

on

Airspace Concept

Communications Navigation ATMSurveillance

PBN

GNSSIRSDME/DMEVOR/DME …

ENROUTE ATSSIDsSTARs …

RNAV-10RNP-4RNP-1RNAV-5 …

Airspace Concept

Communications Navigation ATMSurveillance

ProceduralATS Surveillance (Positive)ADS CADS B

Capabilities of the Airspace

Whatever is available from these items can be thought of as the capabilities for the airspace you are currently in.

RTF (Voice)RTF + Datalink(CPDLC) …

ENROUTE ATSSIDsSTARsGNSSIRSDME/DMEVOR/DME …

Airspace: Putting the Pieces together

Now let’s put the pieces together for a couple of navigation specification examples.

CNS

Oceanic Examples

In the following examples we will look an various airspace with different capabilities available. The capabilities of an airspace allows for specific navigation specification(s).

Airspace

Capabilities

Navigation Specification

Low Traffic Density

Here is an example of possible options over the ocean where 50 nm separation is in use. With these capabilities you have RNAV 10 or RNP 4 available.

50 nm separation

GPS and Datalink are available

Non-radar

High Traffic Density

If the airspace uses 30 nm separation, then you must meet RNP 4 qualification.

30 nm separation

GPS and Datalink are available

Non-radar

GPS not available

Notice if GPS is not available, then RNAV 10 is used. Notice there is no option for high density operations without GPS.

Must be 50 nm separation

IRS only and datalink

Non-radar

Radar Available

Look what happens to the possibilities where radar is in use.

Radar

RNAV 1 & 2 become available to allow more traffic

You’ve got to stay closer to the route

Terminal Area example

Maybe in parts of Africa or South America Basic-RNP 1 is available with GPS. Don’t be confused with the word basic. It is used sometimes to differentiate RNP from approval required , or AR-RNP. In the United States AR is also referred to as Special Aircraft and Aircrew Authorization Required (SAAAR).

GPS is available

Non-radar

Navigation Specifications

Recall, navigation specifications are just one of the two types of airspace mentioned earlier with a specified accuracy level. The accuracy level is the minimum lateral navigation accuracy the equipment must maintain at least 95% of the time and also the total system error, (combined total of all errors) that must be maintained 100% of the time.

A navigation specification is the type of airspace (RNAV or RNP) followed by the containment level number.

Available Navigation Specifications

The available specifications change based on the airspace.

Example

RNP 1Depart

ureRNAV 1Arrival RNP APCH

App

RNAV 2Enroute

RNP 4Oceanic

NavSpec’s Change During Flight

During the flight, you are constantly transiting different airspace. You need to know both the available navigation specifications and the ones you are capable of.

Transition to PBN

The transition to PBN will take many years. Recall PBN is based on area navigation and consists of two types of airspace; RNAV and RNP. You will have to deal with a mixed set of standards for a while.

PRNAV

RNAV 4RNP .3

BRN

AV

RNAV 1

Currently there is a mix of old applications and PBN applications

Eventually the whole world will be singing the PBN tune

Implementation Timeline

So when is all this happening? Here’s a proposed timeline for PBN implementation. They’re a little behind schedule at the moment. Let’s look at some of the current uses RNAV and RNP airspace as we move toward a worldwide airspace system of PBN.

Available Navigation Specifications

To date, the PBN Manual contains eight navigation specifications: four RNAV specifications and four RNP specifications. Nav specs range from simple to complex. A simple one, such as RNAV 5 may not require an on-board navigation database. A more complex one, such as RNP, may require on-board performance monitoring and alerting along with the ability to follow fixed radius turns, such as RNP AR APCH.

BRNAV and PRNAV

Eventually, the old names of BRNAV and PRNAV will no longer be used. Instead, RNAV 5 and RNAV 1 will be used.

BRNAV

PRNAV

RNAV 10

Notice RNP 10 under performance based navigation is really RNAV 10. It will still be allowed in documentation as RNP 10 for practical reasons.

Continental En-route RNAV Applications

Middle East – RNAV 5Europe BRNAV is RNAV 5 (will be renamed later)US RNAV 2

Continental en-route airspace concepts are currently supported by RNAV applications. RNAV 5 is used in the Middle East (MID) and European (EUR) Regions but currently it is designated as B-RNAV in Europe. In the United States, an RNAV 2 application supports an en-route continental airspace concept.

Terminal RNAV Applications - Europe

PRNAV requires RNAV 1 accuracy but is not fully an RNAV 1 navigation specification

The European terminal airspace RNAV application is known as P-RNAV (Precision RNAV), although the RNAV 1 specification shares a common navigation accuracy with P-RNAV, this regional navigation specification does not satisfy the full requirements of the RNAV 1 specification.

Terminal RNAV Applications – U.S.

RNAV 1 is a PBN navigation specification

Currently, the United States terminal airspace formerly known as US RNAV Type B has been aligned with the PBN concept and is now called RNAV 1.

Watch for PBN Implementation

LAN Peru launched the trials Feb. 23 using flights between Lima and major tourism gateway Cusco. General Electric Aviation has installed required navigation performance (RNP) procedures at both airports, which cover the entire flight of almost 1 hr.

Trials of end-to-end performance-based navigation (PBN) procedures on a busy Latin American route mark another incremental step in global PBN development.

Aviation Week & Space Technology Feb 27, 2012

The relevant RNP specifications are RNP APCH and RNP AR APCH

RNP Approach/Departure Applications

new procedures to runways never served by an instrument procedureprocedures either replacing or serving as backup to existing instrument procedures based on different technologiesprocedures developed to enhance airport access in demanding environments

Approach concepts cover all segments of the instrument approach, i.e. initial, intermediate, final and missed approach. They will increasingly call for RNP specifications requiring a navigation accuracy of 0.3 NM to 0.1 NM or lower.

Some SAAR (AR) Approach Attributes

RNP < .3 NMAbility to fly a published arc (also referred to as an RF leg)Reduced lateral obstacle evaluation area on the missed approach (also referred to as a missed approach requiring RNP less than 1.0 NM)

No single-point-of-failure can cause the loss of guidance compliant with the RNP value associated with the approach (or missed approach). Typically, the aircraft must have at least dual GNSS sensors. dual flight management systems, dual air data systems, dual autopilots, and a single inertial reference unit.

SAAAR, (AR) approaches allow approach specific performance requirements as necessary for an approach procedure. The operational requirement can include avoiding terrain and obstacles, de-conflicting airspace or resolving environmental constraints. SAAAR (AR) approaches typically have some or all of these attributes.

EquipmentApproach Criteria

PBN Implementation in U.S.

The FAA defines PBN as “a framework for

defining navigation performance

requirements that can be applied to an air

traffic route, instrument procedure, or

defined airspace.”

PBN, which comprises both RNAV and RNP

specifications, provides a basis for the

design and implementation of automated

flight paths that will facilitate airspace

design, traffic flow, and improved access to

runways.

For additional information, the FAA has a roadmap charting the course to PBN.

PBN SummaryWith the widespread use of area navigation cam the need for navigation approvals

Required Navigation Performance (RNP) is a key enabler of the use of onboard area navigation equipment

As area navigation has evolved, so has the definition of RNP

ICAO standardized the airspace structure around the world

Entry and operation in certain airspace requires approval and maintaining certain performance criteria defined by navigation specifications

From an operational point of view, navigation specifications are the key. The Performance Based Navigation module will help you operate in the airspace during a flight.

Gotta go now