1. P. GAYRAUD /B. RABILLER Cologne the 21st of June 2007
EASA CNS/ATM Steering Group ICAO PBN status and its repercussion on EASA material
P. GAYRAUD /B. RABILLER
Cologne the 21st of June 2007

2. ICAO DOC PBN manual

3. Background
RNP concept initially published by ICAO: Doc 9613 (RNP Manual)
RNP types only identified by an accuracy value
Lack of Airworthiness regulation or Guidance materials (except for RNP 10)
Industry has developed ED-75/DO-236
In parallel, development of RNAVs with specific requirements in different regions of the world
ICAO decision in 2003 to set up RNPSORSG (RNP and Special Requirements Study Group)

4. Status
RNPSORSG outcome: new edition of ICAO Doc 9613 « Performance Based Navigation Manual » superseding the existing RNP Manual
Final draft posted on the ICAO website (VOL I and VOL II)
ICAO State letter dated 27th of April 07 introducing the PBN concept and providing in attachment the VOL II document only (Navigation specification)

5. PBN Manual Content Vol 1: Concepts and Implementation Guidance
Explains how a given Navigation Application (associated with COM, SUR and ATM) can support given operations in an Airspace
Vol 2: Implementing RNAV and RNP (Navigation Specifications)

6. Concepts Performance Based Navigation Concept Navigation application
Navigation specification
NAVAID infrastructure
Performance Based Navigation Concept
Navigation Application. The application of a navigation specification and the supporting Navaid infrastructure, to routes, procedures, and/or defined airspace volume, in accordance with the intended Airspace concept.
Navigation Specification.  A set of aircraft and air crew requirements needed to support Performance based navigation operations within a defined airspace. There are two kinds of navigation specification: RNAV and RNP:
RNP X: A navigation specification with an On-board Performance Monitoring and Alerting function (OPMA)
RNAV X: A navigation specification without an On-board Performance Monitoring and Alerting function
“X” refers to the lateral navigation accuracy in Nm (95%)
RNP = RNAV + OPMA

7. Navigation Specification
Navigation Specifications content:
Required performance (accuracy, integrity, availability and continuity)
Eligible sensors for the achievement of the required performance
Required navigation functionalities in order to meet the required performance
Requirements on the flight crew in order to achieve the required performance from the aircraft and the RNAV system.
Navigation Specifications are not totally « performance-based »:
The requirement allocation to Aircraft, Aircrew and ATM is not independent of technology
The number of technologies is limited (GNSS, IRS, DME…)
Specific requirements on: sensors, navigation functionalities and display
Navigation Specification advantage
Only one set of requirements for a given Navigation Application
Separation or obstacle clearance
Operational aspects
Aircrew and controllers training
Instead of requirements specific to the sensor technology

8. OPMA: On-board Performance Monitoring and Alerting function
A function on board the aircraft detecting and informing the crew when the RNAV system is unable to satisfy the performance prescribed in the Navigation Specification.
This function should monitor all type of errors which may affect the aircraft ability to follow the desired flight path.
The required level of on board monitoring and alerting is stipulated in each RNP navigation specification.
This function may be:
a mix of « automatic » monitoring (e.g NSE monitoring through RAIM) and operational procedure (FTE monitoring by the crew)
or only « automatic » monitoring (e.g TSE monitoring)

9. RNP versus RNAV performance
1 x nav accuracy
95%
Accuracy
Desired route
Accuracy
1 x nav accuracy
95%
RNP Performance
Crew procedure if TSE> threshold
TSE< threshold
99.999%
2 x nav accuracy
TSE Monitoring and alerting
1 x nav accuracy
95%
Accuracy
Desired route
Accuracy
TSE Monitoring and alerting
1 x nav accuracy
95%
99.999%
2 x nav accuracy

10. Overview of navigation specifications (1/2)
Area of application
Navigation
accuracy
Designation of navigation standard
Current situation
Designation of Navigation Specification: PBN concept (new)
Oceanic/Remote 10
RNP 10
RNAV 10 4
RNP 4
En Route Continental 5
B-RNAV
RNAV 5
En route continental and Terminal 2
US-RNAV type A
RNAV 2

11. Overview of navigation specifications (2/2)
Area of application
Navigation
accuracy
Designation of navigation standard
Current situation
Designation of Navigation Specification: PBN concept (new)
Terminal 1
P-RNAV
US-RNAV type B
RNAV 1
N/A
Basic-RNP 1
Approach
0.3
RNAV (GNSS)
RNP APCH
0.3 – 0.1
RNP SAAAR
RNP AR
RNP AR APCH

12. Navigation Specification comparison (1)
RNAV 10
RNAV 5
RNAV 1
RNP 4
BASIC-RNP 1
RNP APCH
Performance Requirements
- Accuracy
- Equipment malfunction
- Continuity
- Signal in Space
10NM 95%
Major
Error > 20 NM,
Prob < 10-7/h
5NM 95%
Minor
Error > 10 NM,
1NM 95%
Error > 2 NM,
4NM 95%
Error > 8 NM,
1-0.3NM 95%
Error > NM,
OPMA
Error > 8NM,
Prob < 10-5
Error > 2NM,
Error > 2-0.6NM,
Minimum equipment
2 LRNS using:
- GNSS
- IRS
1 system using:
- DME/DME
- VOR/DME
2 systems using:
/IRS
2 LRNS using at least:
- GNSS
System using at least:
§ x Specific requirements concerning the positioning function
- 2IRS + GNSS
§ x.3.3

13. Navigation Specification comparison (2)
RNAV 10
RNAV 5
RNAV 1
RNP 4
BASIC-RNP 1
RNP APCH
§ x Functional Requirements
- Display No
Yes + ++
- Navigation Functionalities
§ x.3.4
Operating procedures
§ x.3.5
Pilot Knowledge and Training
§ x.3.6
Navigation Databases
§ x.3.7
Oversight of Operators
 Yes
Yes 
Yes
Yes
Yes
Yes
Yes No
Yes
Yes
Yes
Yes
Yes
Yes
LOA Type 2
LOA Type 2
LOA Type 2
LOA Type 2

14. PBN manual publication repercussion on EASA materials (1/3)
ICAO PBN manual is the most recent document addressing airworthiness and operational criteria
It includes up to date requirements and/or clarifications
In particular those related to recent in service experience and those related to harmonisation with other Authorities (mainly with FAA).
After a first assessment most of AMC/TGL are consistent with the PBN manual except TGL 10 for P-RNAV and the lack of an AMC for RNP 4 and for Basic-RNP 1.

15. PBN manual publication repercussion on EASA materials(2/3)
Area of application
Navigation
accuracy
Designation of navigation standard
Current situation
Designation of navigation specification
PBN concept (new)
EASA material
Oceanic/Remote 10
RNP 10
RNAV 10
AMC “Recognition of FAA Order a for RNP 10 Operations” 4
RNP 4
Herve’s proposal
En Route Continental 5
B-RNAV
RNAV 5
AMC 20-4 “Airworthiness Approval and Operational Criteria For the Use of Navigation Systems in European Airspace Designated For Basic RNAV Operations”
Terminal 1
P-RNAV
US-RNAV type B
RNAV 1
TGL 10 “AIRWORTHINESS AND OPERATIONAL APPROVAL FOR PRECISION RNAV OPERATIONS IN DESIGNATED EUROPEAN AIRSPACE”
and new AMC 20-16
N/A
Basic-RNP 1
No document
Advanced RNP 1 (provision only)
Approach
0.3
RNAV (GNSS)
RNP APCH
AMC 20-XX “AIRWORTHINESS AND OPERATIONAL APPROVAL FOR RNP APPROACH (RNP APCH) OPERATIONS”
RNP SAAAR
RNP AR
RNP AR APCH
AMC 20-XZ “AIRWORTHINESS AND OPERATIONAL APPROVAL FOR RNP AR APPROACH (RNP AR APCH) OPERATIONS”

16. PBN manual publication repercussion on EASA materials (3/3)
PBN repercussions are not significant on EASA materials but general discussions are necessary to prepare the future:
1- What is the role of the RNP RNAV MASPS (DO-236/ ED-75) taking into account the PBN manual publication? Should this standard be amended to be in line with this document?
2- Should future “RNAV” AMCs be only a reference to PBN navigation specification or should AMCs still need to include all the details (stand-alone document)?
3- Should EU-OPS 1 (e.g and 1.865) be amended to reflect the PBN manual in particular in terms of terminology used?

17. Proposed recommendations
The following aspects, should be addressed:
Review and, where necessary, propose update to EU-OPS to ensure requirements for RNAV and RNP operations are consistent with the ICAO PBN manual
Review existing RNAV TGL/AMC and, where necessary, update these documents (e.g. P-RNAV)
Issue, when there is an operational need (e.g. RNP 4), an AMC addressing the related ICAO Navigation Specification. EASA should decide if the AMC content is only a reference to the ICAO Navigation Specification or if it includes all the details (cut and paste of the ICAO Navigation Specification plus refinement if necessary).