# Presentation: 676484

## NAT SPG Activities

- Date:	5-9 November 2007

- Presented to:	IPACG/27

- By:	Dale Livingston

**Review of Performance-Based Communications Approach and Required Communication Performance (RCP)**

## Introduction

**NAT SPG/43, Paris, 12 to 15 June 2007**
- Closure of Goonhilly Ground Earth Station (GES)
- Convene a Special NAT SPG Meeting, Paris, 15-16 Nov 2007
**Prep NAT SPG Meeting held, Paris, 1-3 Oct 2007**
**Agree to performance-based approach and RCP**
**Institutional issues not addressed here**
**Recognized global problem**

## Introduction

**FOM criteria needs to be reinvestigated**
**Status of ICAO standards, recommended practices, guidance material (includes RTCA/EUROCAE)**
- Amendment 40 to Annex 11, November 2001Safety Management
- ICAO Doc 9869, September 2005Manual on RCP
- Amendments to Annexes 6 and 11, November 2007Provisions for RCP
- RTCA DO-306/EUROCAE ED-122, October 2007Oceanic SPR Standard
- Amendment to Doc 4444, in work (nearly complete)Flight Plan Provisions for performance-based and RCP

## ICAO Doc 9869

**Manual on RCP, September 2005**
- Determine RCP type
- Prescribe RCP type
- Compliance initially(Aircraft type design, Operator, ANSP)
- Operational performance monitoring and alerting (Operator and/or ANSP)

## RTCA DO-306/EUROCAE ED-122

**Oceanic SPR Standard, October 2007**
- Data link services used in lieu of HF voice, includes 50 lateral
- Data link services required for 30 nm lateral/30 nm longitudinal and 50 nm longitudinal separation standards
- Considers route conformance monitoring, reroutes, and weather deviations
**Based on RCP Manual and ICAO separation standards**

## 50 longitudinal and 30/30 Intervention(DO-306/ED-122, Table 5-6)

- Normal means

- Alternative means

- ET is at the continuity requirement

## RCP Allocations for Intervention(DO-306/ED-122, Figure 5-3)

**RCP Allocations for Intervention****(DO-306/ED-122, Figure 5-3)**

**Notes:**
Figure 5-3

## 50 longitudinal and 30/30, Surveillance(DO-306/ED-122, Paragraph 5.2.3.4)

**Normal surveillance – The PR service shall deliver a position report within 180 seconds at the continuity requirement and within 90 seconds at 95% probability for:**
- Periodic report, from the start of the periodic interval. The start of the periodic interval occurs when the periodic report is sent by the aircraft (see Figure 5‐2); and
- Waypoint change event report, from the actual time the aircraft crosses the waypoint.
**Normal surveillance – The IER service shall deliver the lateral deviation event report within 180 seconds at the continuity requirement and within 90 seconds at 95% probability from the time the aircraft system detects that the event has occurred.**
**Non-normal surveillance – The IER service delivers a position report within 240 seconds at the continuity requirement and within 180 seconds at 95% probability for ADS‐C demand report or CPDLC position report, from the time the ADS‐C demand contract or CPDLC request was initiated by the ATSU/controller.**

## 50 longitudinal and 30/30Surveillance allocations(DO-306/ED-122, Table 5-7)

- ET is at the continuity requirement

## > 50 lateral and time-based longitudinal Surveillance(DO-306/ED-122, Paragraph 5.2.4.2)

**The PR service shall deliver position reports within 400 seconds at the continuity requirement and within 300 seconds at 95% probability at waypoint crossings from the actual time the aircraft crosses the waypoint.**

## > 50 lateral and time-based longitudinal, Surveillance allocations(DO-306/ED-122, Table 5-8)

- ET is at the continuity requirement

## Continuity, Integrity, and Availability(DO-306/ED-122, Table 5-9)

## Applicability of RCP types(DO-306/ED-122, Table 5-10)

- HF Voice grandfathered in
- For SATCOM voice, HFDL, etc

## Additional requirements

**Communication service availability**
- 0.9999 for operational efficiency (0.999 for safety, per DO­306/ED-122)
- On a per Oceanic ATC Centre (OAC) basis
- No more than 4 outages greater than 10 minutes for any 12 month period
- Failures causing outages for multiple OACs are not counted more than once
- No more than 50 minutes of total downtime for any 12 month period
**Per Appendix A and Appendix C of IPACG WP/nn**

## Additional requirements

**Monitoring and alerting requirement**
- After an outage begins, the communications service shall provide ATC automation with a positive indication that there is an outage within 5 minutes

## Issue

**Based on safety assessment, DO****­****306/ED****­****122 specifies continuity requirement for intervention and surveillance of 0.999**
**This requirement is considered too severe for technical practicality**

## Operational considerations(DO-306/ED-122, Paragraph 5.2.5)

_***Note 1***_***:  The values for availability and continuity provide a basis for further operational safety assessment taking into account other factors and operational judgment.  These values may be adjusted on the basis of a regional air navigation agreement considering the potential conditions of the airspace when the loss of data link capability occurs, including, but not limited to:***
*Air traffic density;*
*Proportion of aircraft using the data link service;*
*Separation minima being applied;*
*Number of aircraft holding a weather deviation clearance in a localized area;*
*Capability and performance of detecting and indicating the loss of the data link services;*
*Capability and performance of route conformance monitoring, e.g., the amount of time after the loss in which the airspace can be considered to be conflict-free; and*
*Capability and performance of the alternative means of communication, including associated procedures for applying an alternative form of separation.*

## Issue resolution

**Given operational considerations, it is suggested that the continuity requirement for intervention and surveillance be adjusted to 0.99 and applied to the time requirements provided in DO****­****306/ED****­****122**
**Notes**
- Continuity adjustment is consistent with current FOM target for continuity
- Per DO-306/ED-122, the technical time requirement (RCTP) associated with intervention is 150 sec at the continuity requirement
- Per the FOM, the target is 360 sec (round trip) at 99%, which is consistent with twice the surveillance latency requirement (one way) provided in DO-306/ED-122

## Recommendation

**Agree to participate in and support implementation of a performance-based approach for communication and surveillance capabilities**
- Prepare a position statement regarding the material provided in Appendices B and C
- The U.S., on behalf of the IPACG, will present the position statement at the Special NAT SPG meeting

## Position statement

**Agree to**
- Recognize DO-306/ED-122 as a basis for establishing performance criteria for communications and surveillance capabilities
- Augmented with 0.9999 availability requirement for operational efficiency
- Adjusted with 0.99 continuity requirement
- 5 minutes for communication service to indicate to OAC that a service outage has occurred

## Recommendation

**Identify points of contact for initial discussions on how to proceed with implementation of a performance-based approach and RCP within the Asia-Pac Region, in coordination with the NAT Region efforts**
- U.S. – Tom Kraft (_[tom.kraft@faa.gov](mailto:tom.kraft@faa.gov)_)
- ISPACG data link group – Paul Radford (_[Paul.Radford@airways.co.nz](mailto:Paul.Radford@airways.co.nz)_)

## Thank you

**Comments?**
**Questions?**