This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
LNAV
Lateral Navigation
Lateral Navigation is an autopilot flight director mode that directs the aircraft to follow the programmed horizontal route as defined in the Flight Management System. When LNAV is engaged, the autopilot computes and executes the necessary bank angles to track each leg of the active flight plan, including straight segments, curved transitions, and procedure turns. LNAV uses GPS or FMS-computed position to maintain precise track along the route, and it sequences the aircraft through waypoints automatically as each leg is completed. LNAV is the horizontal complement to VNAV (Vertical Navigation), and the two modes are typically used together during cruise and descent.
LNAV has specific applications in instrument approach procedures. An LNAV approach is a non-precision approach type that uses GPS or FMS lateral guidance to track the final approach course but relies on a barometric altitude reference for descent - it does not provide glidepath guidance. LNAV minimums are published on RNAV (GPS) approach charts and are typically higher than LNAV/VNAV or LPV minimums. LNAV is also used as the lateral guidance mode during RNAV departures and arrivals (SIDs and STARs), making it one of the most frequently active autopilot modes during a normal commercial flight.