In aviation, LNAV (short for lateral navigation; usually pronounced el-nav) is azimuth navigation without vertical guidance. RNAV approach plates include LNAV as a non-precision instrument approach (NPA). When combined with VNAV the instrument approach, LNAV/VNAV, is referred to as an Approach with Vertical Guidance (APV).
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.:4–24,4–26