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9.4 Arrival Release and Spacing

9.4.1 General

Arrival release and spacing coordination ensures that inbound aircraft are delivered from ACC to APP in a condition suitable for sequencing.

The Approach Controller shall manage spacing to maintain separation, stability, and efficient traffic flow.

9.4.2 Spacing Methods

Spacing between aircraft shall be achieved using:

  • Distance-based separation (e.g. radar separation minima)
  • Time-based intervals (where applicable)

Spacing shall be sufficient to allow stable approach and runway operations.

9.4.3 ACC Responsibilities

The ACC Controller shall:

  • Deliver aircraft with appropriate initial spacing
  • Ensure aircraft are sequenced in accordance with agreed procedures
  • Avoid compression prior to transfer
  • Coordinate with APP when spacing cannot be achieved

9.4.4 Approach Controller Responsibilities

The Approach Controller shall:

  • Assess inbound spacing upon transfer
  • Adjust spacing using speed control and vectoring
  • Establish a stable and continuous arrival sequence
  • Maintain separation at all times

Spacing adjustments shall be made early to avoid corrective action on final approach.

9.4.5 Coordination Requirements

The Approach Controller shall coordinate with ACC when:

  • Spacing is insufficient for safe sequencing
  • Traffic demand exceeds capacity
  • Multiple aircraft require adjustment
  • Non-standard or priority situations exist

Coordination shall be timely and explicit.

9.4.6 Compression Management

The Approach Controller shall:

  • Identify compression early
  • Apply speed control or vectoring to restore spacing
  • Prevent spacing from reducing below minimum separation

Where spacing cannot be restored safely, alternative measures (including delay or go-around) shall be considered.

9.4.7 Limitations

The Approach Controller shall not:

  • Accept inbound traffic without assessing spacing
  • Rely on late corrections close to final approach
  • Allow compression to develop into unsafe conditions
  • Compromise stability in order to maintain throughput

9.4.8 Key Principle

Inbound spacing shall support stable and predictable sequencing.

The Approach Controller shall:

  • Assess early
  • Act early
  • Maintain control of the sequence

Effective spacing coordination reduces workload and ensures safe operations.