In aviation, lateral navigation (LNAV, usually pronounced el-nav) is azimuth navigation, without vertical navigation (VNAV). Area navigation (RNAV) approach plates include LNAV as a non-precision instrument approach (NPA). When combined with VNAV, the resulting 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
- FAA: LNAV (Lateral Navigation) (archived version)
- Instrument Procedures Handbook, FAA-H-8083-16B (PDF). US Dept. of Transportation, FAA Flight Standards Service. 2017. p. 4-26,4-50,G-6.