Which approach type is considered non-precision?

The approach type that is considered non-precision is RNAV/GNSS (LNAV minimums). Non-precision approaches provide lateral guidance only, without the vertical guidance necessary to maintain a specific vertical profile during descent. In the case of RNAV/GNSS approaches categorized under LNAV minimums, pilots rely on satellite navigation to follow a prescribed lateral path to the runway, but they do not receive information that helps them maintain a specific vertical descent rate. Therefore, pilots must often perform what is known as a "step-down" approach.

In contrast, other approach types like ILS and GLS offer precision approaches, providing both lateral and precise vertical guidance to the runway. This allows for a more controlled descent and approach path, contributing to safer landings, especially in low visibility conditions. The PAR approach also provides precision guidance, using an instrument landing system that offers both lateral and vertical navigational data.