Instrument Approaches

The instrument approach is the final phase of IFR flight, guiding the aircraft from the cruise/holding phase to the point where the pilot can land visually or execute a go-around.

Approach Structure

An instrument approach is broken down into segments:

1. Initial Approach Segment

Transition from the airway or holding pattern to the Initial Approach Fix (IAF).

2. Intermediate Approach Segment

From the IAF to the Final Approach Fix (FAF). Stabilization of the trajectory and speed.

3. Final Approach Segment

From the FAF to the Missed Approach Point (MAPt). This is the descent segment toward the runway.

4. Missed Approach

If the pilot does not have visual contact at the MAPt, they execute the missed approach (go-around) according to the published procedure.

Approach Types

VOR Approach

Based on a VOR radial aligned (or close to) the runway axis:

• Lateral guidance only (no vertical guidance)
• The pilot descends in steps according to prescribed minimum altitudes
• Accuracy: ± 1° (i.e., ± 0.17 NM at 10 NM)

NDB Approach

Based on an NDB located on or near the aerodrome:

• The pilot tracks to the NDB by maintaining a constant QDM
• Less accurate than VOR (± 5°)
• Requires good drift correction

Success Criteria

On approach, precision criteria are stricter than en route:

In HOLD: Approach scenarios evaluate trajectory accuracy, altitude compliance, and final heading stability.