Section 4, Chapter 4 - Oceanic Area Control

Question 1

What are the key points related to Oceanic Area Control and Shanwick OAC?

Answer 1

• General Procedures: Relevant to controllers operating in adjacent domestic airspace, with more details in MATS Part 2.
• Shanwick OAC Services: Provides Area Control, ICAO Standard FIS, and Alerting Services within the Shanwick OCA.
• FDPS Assistance: The oceanic controller uses an FDPS for conflict prediction, detection, automatic update of flight profiles, and data transfer to adjacent units.
• Vertical Limits: The Shanwick OCA extends from FL55 with no upper limit; airspace at and above FL55 is Class A. VMC climbs or descents are not permitted.

Question 2

What are the requirements for Air Traffic Control clearances when entering the Shanwick OCA?

Answer 2

• Aircraft entering the Shanwick OCA from domestic airspace must obtain an oceanic clearance from Shanwick.
• The clearance is effective only at the Shanwick OCA boundary.
• The pilot is responsible for obtaining any necessary clearance or re-clearance to comply with the oceanic clearance.

Question 3

What are the methods for obtaining clearances for westbound aircraft entering the Shanwick OCA?

Answer 3

VHF RTF:

• Aircraft in the UK UIR/FIR and northern France UIR should request oceanic clearance from “Shanwick Oceanic” on VHF RTF.
• UK departures should request clearance as soon as possible after departure.
• Overflying aircraft should request clearance when within VHF RTF range of “Shanwick Oceanic.”
• Non-turbojet aircraft should request clearance at least 40 minutes before the ETA for the OCA entry point.

HF RTF (NARTEL):

• Aircraft unable to contact Shanwick on VHF should request clearance on the North Atlantic en-route HF RTF Network at least 40 minutes before the ETA for the oceanic boundary.
• Maintain a SELCAL watch for receipt of the oceanic clearance.

Communication Requirements:

• While obtaining oceanic clearance, aircraft must also maintain communication with the ATC authority for the airspace in which they are operating.
• If unable to contact Shanwick on VHF or NARTEL HF, request the current ATC authority to relay the oceanic clearance request to Shanwick.

Question 4

What is the Oceanic Route Clearance Authorisation (ORCA) System and how do pilots use it to obtain oceanic clearance?

Answer 4

• Eligibility: Suitably equipped aircraft entering Shanwick airspace between ATSIX and PASAS can use the VHF datalink.
• Timing: Requests for oceanic clearance via datalink should be made 30 to 90 minutes prior to the oceanic boundary.

Equipment Specifications:
* ARINC 623: Allows pilots to request, receive, and acknowledge oceanic clearance via datalink.
* ARINC 620: Allows pilots to request and receive oceanic clearance via datalink, but requires voice read-back to confirm the clearance.

Question 5

What information must be included in requests for oceanic clearance?

Answer 5

• Callsign
• OCA entry point and ETA
• Requested Mach number and flight level
• Any changes to the flight plan affecting OCA

Question 6

What are the contents of oceanic clearances, including abbreviated clearances, for aircraft?

Answer 6

• Abbreviated Clearance: Issued only for organized track flights within NAT OCAs and includes:

1. Track specified by track code
2. Flight level(s)
3. Mach number
4. “Send Met reports” if meteorological reporting is required

• Full Clearance: Provided in all other cases with full details of the cleared path.
• Mach Number: Included in each clearance for subsonic aircraft operating within Gander, New York, Reykjavik, Santa Maria, and Shanwick OCAs.

Question 7

What is the Organised Track Structure for oceanic airspace and how are the tracks managed?

Answer 7

• Purpose: Allows optimum use of oceanic airspace during peak traffic periods, based on requested turbo-jet routes, meteorological data, airspace reservations, lateral separation minima, and traffic density.
• Track System: Organized with appropriate coordination.
• Responsibility:
  1. Shanwick: Establishes and publishes westbound tracks (designators A to M).
  2. Gander: Establishes and publishes eastbound tracks (designators N to Z, excluding I and O).

Question 8

What are the periods of operation and notification requirements for the Organised Track Structure?

Answer 8

Periods of Operation:
1. Westbound: 1130 to 1900 UTC
2. Eastbound: 0100 to 0800 UTC

• Applicability: Times are applicable at 30 degrees west.
• Notification: The track signal must be dispatched at least 8 hours in advance of their period of operation. Any changes to the structure should be notified as soon as practicable.

Question 9

What are the separation requirements for aircraft within the Oceanic Control Area (OCA)?

Answer 9

• Standard Separation: In accordance with ICAO Doc. 7030.
• Increased Separation: Applied during ionospheric or radio blackout periods, or when necessary.

Separation Minima:
* Horizontal and Longitudinal: Greater than standard domestic separation in certain circumstances.
* Shanwick OCA: Specific separation minima are detailed in MATS Part 2 and apply when crossing the oceanic/domestic airspace boundary.