**THE TWENTY-SEVENTH MEETING OF THE**

**INFORMAL PACIFIC ATC CO-ORDINATING GROUP**

**(IPACG/27)**

(Tokyo, Japan, 5-9 November, 2007)

Agenda Item 5: Air Traffic Management (ATM) Issues

**Operational Trial of 30 NM Separation and Use of 50 NM Longitudinal
Separation in the Oakland Oceanic Control Area**

(Presented by the Federal Aviation Administration)

**[SUMMARY]{.underline}**

This information paper provides a status update on the use of 30 NM
lateral / 30 NM longitudinal separation (30/30) and 50 NM longitudinal
separation between appropriately authorized and equipped aircraft
throughout the Oakland Oceanic Control Area.

1.  **Initial Operational Trial Phases.** In December 2005, the FAA
    began an operational trial of 30 nautical mile (NM) lateral and 30
    NM longitudinal (30/30) separation in Oakland Oceanic Control Area
    (CTA) Sector 3. In March 2007, the trial was expanded, with
    limitations, to all Oakland oceanic sectors. 30/30 and 50 NM
    longitudinal separation were applied only between eligible aircraft
    to enable same direction aircraft to climb or descend through the
    altitude of other aircraft and to enable opposite direction aircraft
    to climb or descend through or cruise at the altitude of other
    aircraft.

**2. Current Operational Trial Policies.** Since June 2007, the Oakland
Air Route Traffic Control Center (ARTCC) has applied 30 NM lateral and
30 NM longitudinal (30/30) separation and 50 NM longitudinal separation
between appropriately authorized and equipped aircraft throughout the
Oakland Oceanic CTA. The policies for the application of the separation
minima are detailed below:

-   30/30 and 50 NM longitudinal separation is applied to "targets of
    opportunity" throughout the Oakland Oceanic CTA. "Targets of
    Opportunity" are proximate pairs of aircraft that are both eligible
    for either 30/30 separation or 50 NM longitudinal separation.

-   Published ATS routes and other tracks (e.g. Pacific Organized Track
    System) continue to be laterally separated by a minimum of 50 NM.

```{=html}
<!-- -->
```
-   50 NM remains the minimum Automatic Dependent Surveillance (ADS)
    based lateral and longitudinal separation applied between 30/30
    eligible aircraft and Required Navigation Performance 10 (RNP-10)
    aircraft. Lateral and longitudinal separation standards applied
    between RNP-10 and non-RNP aircraft also remain unchanged.

-   Oakland ARTCC accommodates operators that are not eligible for 30 NM
    separation throughout Oakland Oceanic CTA. Lateral, longitudinal and
    vertical separation minima for aircraft not eligible for 30 NM
    separation are unchanged.

**3. FAA Operational Policy Notice.**

3.1 The operational policies, requirements and recommendations for
operators planning for 30 nm separation in the Oakland Oceanic CTA are
published in an FAA notice entitled "Oakland Oceanic Control Area (CTA):
Continuation of Operational Trials for 30 nm Separation And Use of 50
Nautical Mile (nm) Longitudinal Separation". The notice is posted on the
"Pacific CNS Requirements/Options" webpage:

> [**http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/enroute/oceanic/pacific_cns/**](http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/enroute/oceanic/pacific_cns/)

3.2 The notice details the operator/aircraft equipage requirements for
30/30 eligibility: FANS 1/A package (or equivalent), satellite
Controller-Pilot Data Link Communications, RNP 4 navigation and
Automatic Dependent Surveillance -- Contract (ADS-C).

**4. Role of the OSRWG Scrutiny Group.** The FAA Oceanic Separation
Reduction Working Group (OSRWG) Scrutiny Group was established to
evaluate the operational and technical issues related to 30/30
operations including the performance of the satellite data link system.
It includes subject matter experts from air traffic, flight standards,
aircraft certification and safety analysis. The Scrutiny Group was
responsible for recommending to FAA managers the readiness to start
30/30 operational trials and the policies to be applied. The Scrutiny
Group meets at regular intervals to assess the status of operations.

**5. Scrutiny Group Findings**

5.1 The 14-15 August meeting found:

5.1.1 The Oakland Oceanic CTA averages 638 flights per day. 35% of those
flights use ADS and 12% of total flights are eligible for application of
30/30.

5.1.2 On major individual traffic flows, the following percentage of
flights are 30/30 eligible:

-   Approximately 58% of flights between North America and South Pacific
    destinations.

-   Approximately 26% of flights between North America and Northern Asia
    destinations.

-   Approximately 12% of flights between Japan and Hawaii.

-   Approximately 10% of flights between Japan and South Pacific
    destinations.

-   Approximately 3% of flights between the U.S. mainland and Hawaii.

5.1.3 Data link service availability was 99.83% with outages experienced
at rate of

15 hours per year. (Availability is defined as the ability of the
network data link service to perform a required function, under given
conditions, at a given time).

5.1.4 Data link service reliability was 99.72% with a mean time between
service outages of 352.2 hours. (Reliability is defined as the ability
of the data link system to perform a required function under given
conditions for a given time interval).

5.1.5 For May - July, the target of 1% missing basic (BAS) periodic
reports was met**.**

5.1.6 Scrutiny Group Conclusions. The Scrutiny Group concluded that
30/30 operations should continue on an operational trial basis and that
the group should continue to monitor satellite data link performance.
The next Scrutiny Group meeting was scheduled for 30-31 October.

**6. Recommendation**

6.1 The group is invited to note and discuss the status of 30/30
operational trials as presented in this paper.

\- END -