- A two-dimensional (2D) instrument approach operation, using lateral navigation guidance only; and
- A three-dimensional (3D) instrument approach operation, using both lateral and vertical navigation guidance.
Note: Lateral and vertical navigation guidance refers to the guidance provided either by:
- a ground-based radio navigation aid; or
- computer-generated navigation data from ground-based, space-based, self-contained navigation aids or a combination of these.
Instrument Approach Operations [ICAO]