Final answer:
Non-precision approaches in aviation are those that provide only vertical guidance for aircraft landing. The main types are VOR, NDB, and RNAV approaches, with RNAV approaches growing in use due to improved accuracy.
Step-by-step explanation:
In aviation, non-precision approaches refer to instrument approaches for landing an aircraft that do not include horizontal navigation guidance – only vertical. The main types of non-precision approaches include VOR (VHF Omnidirectional Range), NDB (Non-Directional Beacon) and RNAV (Area Navigation) approaches.
VOR utilizes radio signals to provide the pilot with a specific course to or from the station. NDB, on the other hand, relies on automatic direction finders in the aircraft that hone in on the signal of the beacon. RNAV approaches use GPS or other navigational systems and are increasingly replacing VOR and NDB approaches due to their increased accuracy and flexibility.
Learn more about Non-Precision Approaches