LNAV
In aviation, LNAV is azimuth navigation without vertical guidance. RNAV approach plates include LNAV as a non-precision instrument approach. When combined with VNAV the instrument approach, LNAV/VNAV, is referred to as an Approach with Vertical Guidance.An LNAV approach is flown to a Minimum Descent Altitude, MDA, while an LNAV/VNAV approach is flown to a Decision Altitude, DA. If WAAS becomes unavailable, a GPS or WAAS equipped aircraft can revert to the LNAV MDA using GPS only.
