The paper presents the development and the simulation results of a GPS-based waypoints Fuzzy Guidance System (FGS). Waypoints are described in a 5-dimensional space: standard position in 3-dimensions plus desired crossing heading and velocity. The aircraft is assumed to be autopiloted in velocity, heading and flight path. The FGS is based on three standard Mamdani fuzzy controllers that generate separately velocity, heading and flight path references for the autopilots. Simulation results show that, under the FGS guidance, the aircraft correctly crosses all waypoints in the specified sequential order. The FGS handles a non-flyable waypoints set as well, driving the aircraft on flyable trajectories that try to cross the waypoints at the prescribed altitude and with prescribed heading. Copyright (C) 2001 IFAC.