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6.3 Non-Precision Approaches (RNAV / GNSS)

6.3.1 General

Non-precision approaches provide lateral guidance, and in some cases vertical guidance, without the use of ground-based ILS systems.

RNAV (GNSS) approaches rely on satellite navigation and onboard aircraft systems.

The Approach Controller shall position aircraft accurately to ensure safe execution of the approach.

6.3.2 Characteristics

Non-precision approaches:

  • Do not rely on ground-based localiser or glide slope
  • May provide vertical guidance (e.g. LNAV/VNAV)
  • Require accurate lateral positioning prior to final approach

6.3.3 Controller Responsibilities

The Approach Controller shall:

  • Position aircraft to intercept the final approach track prior to the Final Approach Fix (FAF)
  • Ensure aircraft are established on the correct track before approach clearance
  • Provide sufficient spacing between aircraft
  • Deliver aircraft in a stable and predictable condition

Approach clearance shall only be issued when positioning and separation are assured.

6.3.4 Positioning Requirements

The Approach Controller shall:

  • Ensure aircraft are aligned with the final approach track
  • Avoid excessive intercept angles
  • Issue vectors early to achieve accurate positioning

Accurate positioning is critical for successful execution of non-precision approaches.

6.3.5 Differences from Precision Approaches

Compared to ILS approaches:

  • No external lateral or vertical guidance is provided by ground systems
  • Greater reliance is placed on aircraft navigation systems
  • There is reduced tolerance for incorrect positioning

The Approach Controller shall ensure higher accuracy in vectoring.

6.3.6 Stability Considerations

The Approach Controller shall ensure that:

  • Aircraft are established on the final approach track prior to the FAF
  • Minimal correction is required after intercept
  • The aircraft can maintain a stable descent profile

Unstable approaches shall be corrected early or a go-around shall be expected or instructed.

6.3.7 Limitations

The Approach Controller shall not:

  • Issue late vectoring close to the FAF
  • Create excessive intercept angles
  • Deliver aircraft in unstable conditions
  • Rely on pilot correction to achieve alignment

6.3.8 Key Principle

Non-precision approaches require accurate and early positioning.

The Approach Controller shall:

  • Plan ahead
  • Position precisely
  • Deliver stable approaches

Less guidance means less tolerance for error.