An instrument approach is a type of air navigation that allows an aircraft to land in weather restricting visibility, or to reach visual conditions permitting a landing.
An approach is essentially classified as either precision or nonprecision, depending on the accuracy and capabilities of the navigational aids used. Also, a nonprecision approach has no glideslope available to the pilot.
Precision approach types
- ILS - Instrument Landing System
- MLS - Microwave Landing System
- PAR - Precision Approach Radar (Military)
- GPS (with vertical navigation) - Global Positioning System
Nonprecision approach types