ENR 7.5: Operational Policy Performance-Based Navigation (PBN) and Performance-Based Communication and Surveillance (PBCS)

1.1 Distance-based longitudinal separation minima using ADS-C is implemented in the Oakland Oceanic, Anchorage Oceanic and New York Oceanic airspace as specified in TBL ENR 7.5-1.

1.2 Aircraft Future Air Navigation System (FANS) 1/A communications, navigation and surveillance (CNS) capabilities, interfaced with Advanced Technology and Oceanic Procedures (ATOP), are required for ADS-C distance based separation to be applied.

1.3 23 NM lateral separation is applied between RNP 4 aircraft capable of RSP 180 and RCP 240 with ADS-C waypoint change event and 5 NM lateral deviation event contracts established.

2.1 Oakland, New York and Anchorage ARTCCs will apply the following policies to the use of ADS-C distance based separation:

2.1.1 The separation will be applied to pairs of suitably equipped pairs of aircraft;

2.1.2 Minimum ADS-C based longitudinal separation between RNP 4 eligible aircraft and RNP 10 eligible aircraft is 50 NM; and

2.1.3 Lateral and longitudinal separation standards applied between RNP 10 and non-RNP 10 aircraft remains unchanged.

3.1 The aircraft and operator must be authorized by the State of the Operator or the State of Registry, as appropriate, for 50 NM: at a minimum, RNP 4 or RNAV 10, RCP 240, and RSP 180; and for 30 NM: at a minimum, RNP 4, RCP 240, and RSP 180 operations;

3.2 The aircraft must be equipped with a minimum of two approved long range navigation systems that will enable the aircraft to maintain RNP 4 for the duration of flight in the applicable airspace;

3.3 The aircraft must be equipped with a FANS1/A package (or equivalent) that includes satellite Controller Pilot Data Link Communication (CPDLC) and ADS-C that meet the standards of RTCA Document 258, Interoperability Requirements for ATS Applications Using ARINC 622 Data Communications;

3.4 Satellite CPDLC communications and ADS-C surveillance must be conducted in accordance with the ICAO Global Operational Data Link Document (GOLD).

3.5 Pilots and dispatchers must be trained on policies and procedures applicable to ADS-C distance based separation, including the use of Satellite CPDLC and ADS-C.

3.6 Operators should use the ICAO GOLD to develop policy and procedures for CPDLC and ADS-C operations.

3.6.1 Operators must use one of the following documents to develop policy and procedures for RNP 4 operations:

3.6.1.1 FAA Advisory Circular (AC) 90-105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace;

3.6.1.2 Australian Civil Aviation Safety Authority (CASA) Advisory Circular 91U3(0); or

3.6.1.3 ICAO Performance-Based Navigation (PBN) Manual ( ICAO Document 9613), Volume II, Part C, Chapter 1.

3.6.1.4 ICAO Performance-Based Communication and Surveillance (PBCS) Manual ( ICAO Doc 9869).

5.1 Pilots should be aware that ADS-C distance based separation can be applied to their aircraft. They should use all available tools to maintain an awareness of other aircraft in their proximity in case an inflight contingency occurs (e.g., aircraft or ATC system malfunction).

5.2 Pilots must advise ATC of a loss of CPDLC and/or ADS-C capability or an inability to continue to meet RNP 4. ATC will transition the aircraft to another form of separation as expeditiously as possible.

5.3 ATC will advise pilots if there is a known malfunction of the CPDLC or ADS-C system. If necessary, ATC will apply a different separation standard, which may involve a route or altitude change.

5.4 Pilots should use the guidance in ENR 7.3, Special Procedures for In−Flight Contingencies in Oceanic Airspace. This reflects current ICAO guidance calling for a 5 NM track offset when unable to obtain ATC clearance prior to executing maneuvers for contingencies such as rapid descent, turn back, or diversion. This is of particular importance for aircraft to which ADS-C distance-based separation can be applied.

5.5 Pilots are required to maneuver (deviate) around convective weather on a regular basis. The enhanced CNS requirements and capabilities aid pilots and controllers in situations where aircraft are required to maneuver around convective weather. For weather avoidance maneuvers in areas where ADS-C distance based separation is applied, operators should emphasize the following items in pilot training programs:

5.5.1 Pilots should not assume the ATOP system will quickly detect significant changes to the aircraft flight path. Aircraft position is updated to the ATOP system at intervals of up to 27 minutes.

5.5.2 It is imperative that pilots keep ATC advised via CPDLC (or HF voice, if necessary) of their intentions (including significant airspeed changes) during maneuvers to avoid convective weather. Pilots must inform ATC expeditiously of changes to flight path or airspeed that could erode separation.

5.5.3 Pilots must be familiar with ENR 7.3, Special Procedures for In-Flight Contingencies in Oceanic Airspace.

5.5.4 It is recommended that ACAS/TCAS be operational for aircraft to which ADS-C distance based separation can be applied. ACAS/TCAS provide a valuable tool to alert the pilot to the presence and proximity of nearby aircraft in weather deviation situations.

5.5.5 In accordance with ICAO Document 4444, pilots are reminded that, regardless of the magnitude of a deviation from assigned route, clearance should be requested in advance from ATC. Prior coordination with ATC will help prevent the aircraft generating unnecessary alerts to ATC for lateral deviation events.

5.5.6 Operators should consider adopting guidance for pilots to use heading mode to maneuver around areas of convective weather. Use of heading mode will prevent transmission of unnecessary lateral deviation event alerts that some flight management systems (FMS) automatically transmit to ATC when the FMS automatic lateral offset feature is used for weather avoidance. It should be emphasized that, when using heading mode, pilots should monitor cross track and heading and return to track when weather avoidance maneuvering is complete.

5.5.7 Aircraft navigation errors and system malfunctions will be monitored and documented. Operators should cooperate in follow up investigation of these events.