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7.5 Mixed Aircraft Types

7.5.1 General

Different aircraft types have varying performance characteristics which affect sequencing, spacing, and approach stability.

The Approach Controller shall consider aircraft type when establishing and maintaining the sequence.

7.5.2 Speed Considerations

Aircraft approach speeds vary significantly:

  • Heavy / Jet aircraft – higher and more stable approach speeds
  • Medium aircraft – moderate speeds
  • Light aircraft / Turboprops – lower and more variable speeds

The Approach Controller shall:

  • Anticipate speed differences early
  • Avoid placing slower aircraft ahead of significantly faster aircraft
  • Apply speed control proactively

7.5.3 Wake Turbulence Categories

Aircraft are categorised as:

  • SUPER (J)
  • HEAVY (H)
  • MEDIUM (M)
  • LIGHT (L)

Wake turbulence separation shall be applied based on the leading aircraft category.

7.5.4 Wake Turbulence Separation (Radar)

Leading Aircraft Following Aircraft Minimum Separation
SUPER HEAVY / MEDIUM / LIGHT 6–8 NM*
HEAVY MEDIUM 5 NM
HEAVY LIGHT 6 NM
MEDIUM LIGHT 5 NM

*Exact values may vary by local procedures; use conservative spacing in training environments.

7.5.5 Sequencing Techniques

The Approach Controller shall:

  • Sequence similar aircraft types together where possible
  • Use speed control early to manage differences
  • Increase spacing when mixing aircraft categories
  • Avoid compressing faster aircraft behind slower traffic

7.5.6 Operational Considerations

The Approach Controller shall consider:

  • Aircraft performance and climb/descent capability
  • Speed variation on final approach
  • Wake turbulence impact
  • Runway occupancy time

7.5.7 Limitations

The Approach Controller shall not:

  • Apply standard spacing without considering wake turbulence
  • Allow faster aircraft to close excessively on slower aircraft
  • Rely on late corrections to resolve speed differences

7.5.8 Key Principle

Mixed traffic requires proactive sequencing.

The Approach Controller shall:

  • Plan for aircraft performance differences
  • Apply appropriate spacing early
  • Maintain a stable and predictable sequence

Effective handling of mixed aircraft types prevents compression and ensures safe operations.