Section 2. ATOP - Oceanic

  • Views Views: 767
  • Last updated Last updated:
  • Section 2. ATOP - Oceanic

    The following procedures are applicable to the operation of the ATOP Oceanic Air Traffic Control (ATC) System.

    13-2-1. DESCRIPTION

    1. The ATOP ATC System is utilized in designated en route/oceanic airspace. ATOP includes both surveillance and flight data processing, which provides the controllers with automated decision support tools to establish, monitor and maintain separation between aircraft, and aircraft to airspace and terrain.
    2. ATOP capabilities include:
      1. MEARTS based radar surveillance processing.
      2. Conflict Prediction and Reporting.
      3. Automatic Dependent Surveillance- Broadcast (ADS-B).
      4. Automatic Dependent Surveillance- Contract (ADS-C).
      5. Controller Pilot Data Link Communications (CPDLC).
      6. ATS Interfacility Data Communications (AIDC).
      7. Additional Decision Support Tools used primarily for situational awareness.
      8. Electronic Flight Data including Electronic Flight Strips.


    The controller must use the most accurate information available to initiate, monitor, and maintain separation.

    1. Apply the following procedures in airspace where conflict probe is being utilized as a decision support tool:
      1. Conflict Probe Results.
        1. (a) Controllers must assume that the conflict probe separation calculations are accurate.
        2. (b) Unless otherwise prescribed in subparagraph a3, controllers must utilize the results from conflict probe to initiate and maintain the prescribed separation minima.
      2. Conflict Resolution.
        1. (a) When a controller is alerted to a conflict, which will occur in his/her sector, take the appropriate action to resolve the conflict.
        2. (b) The controller responsible for resolving a conflict must evaluate the alert and take appropriate action as early as practical, in accordance with duty priorities, alert priority, and operational considerations.
        3. (c) Unless otherwise specified in facility directives, the controller must take immediate action to resolve any “red” conflicts.
      3. Overriding Conflict Probe.
        1. (a) Controllers must not override conflict probe except for the following situations:
          1. (1) The application of a separation standard not recognized by conflict probe listed in subparagraph a8(a), or as identified by facility directive.
          2. (2) When action has been taken to resolve the identified conflict and separation has been ensured, or
          3. (3) Control responsibility has been delegated to another sector or facility, or
          4. (4) Other situations as specified in facility directives.
        2. (b) Controllers must continue to ensure that separation is maintained until the overridden conflict is resolved.
      4. Use of Probe when Issuing Clearances. Utilize conflict probe results when issuing a clearance to ensure that any potential conflict has been given thorough consideration.
      5. Use of Probe when Accepting Manual Transfers. Prior to manually accepting an aircraft transfer from an external facility ensure that the coordinated flight profile is accurately entered, conflict probe initiated and, if necessary, action is taken to resolve any potential conflicts.
      6. Trial Probe. The controller can utilize trial probe to assess whether there are any potential conflicts with a proposed clearance or when performing manual coordination.

        NOTE: Once initiated, trial probe does not take into account any changes made to the proposed profile or to any other flight profile in the system. It is an assessment by conflict probe of the current situation at the time the controller enters the trial probe. A trial probe does not alleviate the controller from performing a conflict probe when issuing a clearance or accepting a transfer.

      7. System Unable to Perform Conflict Probe for a Specific Aircraft.
        1. (a) If a flight's profile becomes corrupted, conflict probe may not be able to correctly monitor separation for that flight. Take the necessary steps to correct an aircraft's flight plan when conflict probe could not be performed.
        2. (b) In addition, after verifying flight plan data accuracy, utilize other decision support tools to establish and maintain the appropriate separation minima until such time that conflict probe can be utilized.
      8. Conflict Probe Limitations.
        1. (a) Conflict Probe does not support the following separation minima:
          1. (1) Subparagraph 8-4-2a2 - Nonintersecting paths.
          2. (2) Subparagraph 8-4-2d - Intersecting flight paths with variable width protected airspace.
          3. (3) Subparagraph 8-4-3a - Reduction of Route Protected Airspace, below FL 240.
          4. (4) Subparagraph 8-4-3b - Reduction of Route Protected Airspace, at and above FL 240.
          5. (5) Subparagraph 8-4-4a1 - Same NAVAID: VOR/VORTAC/TACAN.
          6. (6) Subparagraph 8-4-4a2 - Same NAVAID: NDB.
          7. (7) Subparagraph 8-4-4c - Dead Reckoning.
          8. (8) Paragraph 8-5-4 - Same Direction.
          9. (9) Paragraph 8-8-5 - VFR Climb and Descent.
    2. Additional Decision Support Tools: These support tools include: range/bearing, time of passing, intercept angle, the aircraft situation display (ASD) and electronic flight data.
      1. The results provided by these additional decision support/controller tools can be used by the controller for maintaining situational awareness and monitoring flight profile information, and for establishing and maintaining separation standards not supported by probe, or when probe is unavailable.
      2. Under no circumstances must the controller utilize any of the additional decision support tools to override probe results when the applicable separation standard is supported by probe and none of the other conditions for overriding probe apply.


    1. Currency of Information: The sector team is responsible for ensuring that manually entered data is accurate and timely. Ensure that nonconformant messages are handled in a timely manner and that the flight's profile is updated as necessary.

      NOTE: Conflict probe accuracy requires timely updates of data used to model each flight's trajectory. If this data is not current, the aircraft flight profile and probe results may be misleading.

    2. Data Block Management.
      1. Ensure that the data block reflects the most current flight information and controller applied indicators as specified in facility directives.
      2. Ensure that appropriate and timely action is taken when a special condition code is indicated in the data block.
    3. Electronic Flight Strip Management.
      1. Electronic flight strips must be maintained in accordance with facility directives and the following:
        1. (a) Annotations. Ensure that annotations are kept up to date.
        2. (b) Reduced Separation Flags. Ensure the flags listed below are selected appropriately for each flight:
          1. (1) M- Mach Number Technique (MNT).
          2. (2) R- Reduced MNT.
          3. (3) D- Distance-based longitudinal.
          4. (4) W- Reduced Vertical Separation Minimum (RVSM).
        3. (c) Degraded RNP. Select when an aircraft has notified ATC of a reduction in navigation capability that affects the applicable separation minima.
        4. (d) Restrictions. Ensure restrictions accurately reflect the cleared profile.
    4. Queue Management.
      1. Manage all sector and coordination queues in accordance with the appropriate message priority and the controller's priority of duties.
      2. In accordance with facility directives, ensure that the messages directed to the error queue are processed in a timely manner.
    5. Window/List Management.
      1. Ensure that the situation display window title bar is not obscured by other windows and/or lists.

        NOTE: The title bar changes color to denote when priority information on the ASD is being obscured or is out of view.

      2. In accordance with facility directives, ensure that designated windows and/or lists are displayed at all times.


    1. Means of communication.
      1. When CPDLC is available and CPDLC connected aircraft are operating outside of VHF coverage, CPDLC must be used as the primary means of communication.
      2. Voice communications may be utilized for CPDLC aircraft when it will provide an operational advantage and/or when workload or equipment capabilities demand.
      3. When CPDLC is being utilized, a voice backup must exist (e.g., HF, SATCOM, Third party).
      4. When a pilot communicates via CPDLC, the response should be via CPDLC.
      5. To the extent possible, the CPDLC message set should be used in lieu of free text messages.

        NOTE: The use of the CPDLC message set ensures the proper “closure” of CPDLC exchanges.

    2. Transfer of Communications to the Next Facility.
      1. When the receiving facility is capable of CPDLC communications, the data link transfer is automatic and is accomplished within facility adapted parameters.
      2. When a receiving facility is not CPDLC capable, the transfer of communications must be made in accordance with local directives and Letters of Agreement (LOAs).
    3. Abnormal conditions.
      1. If any portion of the automated transfer fails, the controller should attempt to initiate the transfer manually. If unable to complete the data link transfer, the controller should advise the pilot to log on to the next facility and send an End Service (EOS) message.
      2. If CPDLC fails, voice communications must be utilized until CPDLC connections can be reestablished.
      3. If the CPDLC connection is lost on a specific aircraft, the controller should send a connection request message (CR1) or advise the pilot via backup communications to log on again.
      4. If CPDLC service is to be canceled, the controller must advise the pilot as early as possible to facilitate a smooth transition to voice communications. Workload permitting, the controller should also advise the pilot of the reason for the termination of data link.
      5. When there is uncertainty that a clearance was delivered to an aircraft via CPDLC, the controller must continue to protect the airspace associated with the clearance until an appropriate operational response is received from the flight crew. If an expected operational response to a clearance is not received, the controller will initiate appropriate action to ensure that the clearance was received by the flight crew. On initial voice contact with aircraft preface the message with the following:
        • (Call Sign) CPDLC Failure, (message).

    13-2-5. COORDINATION

    In addition to the requirements set forth in Chapter 8, Offshore/Oceanic Procedures, Section 2, Coordination, automated coordination must constitute complete coordination between ATOP sectors, both internally and between sectors across adjacent ATOP facilities, except:

    1. When the aircraft is in conflict with another in the receiving sector, or
    2. When otherwise specified in facility directives or LOA.


    1. When operating in a multiple controller operation at a workstation, ensure all ATC tasks are completed according to their priority of duties.
    2. Multiple controller operation must be accomplished according to facility directives.
Top Bottom