Military helicopter Nap-of-the-Earth (NOE) flight is one of the most demanding low-altitude, near terrain Nght operations.In NOE, the pilot is operating a t o r below tree-top levels, taking maximum advantage of the terrain and ground featurn for concealment Such increased proximity to obstructions places heightened maneuverability rquirements on the aircrafl and extreme levels of workload on the pilotThe basic issue being addressed in the NASA Automated Nap-of-the-Earth (ANOE) program is the intelligent use of environmental information such as knowledge of terrain, obstacles, and other external factors to enhance the flight path guidance of the vehicle. This is a major departure over contemporary guidanceand control based on feedback of state variablessuch as vehicle attitudes, velocities, and accelerations. Although the immediate program has a military foeus, the technological advances inherent for automating NOE flight have great benefit to the operation of a wide class of vehicles such as emergency medical helicopters, conventional and high-speed transports, unmanned aerial vehicles, and planetary vehicles.This paper summarizes results to date of the NASA ANOE program in the areas of passive and active sensors, pilot dii plays, low-altitude manual trajectory guidance, and NOE automatic guidance. Each of these areas has been developed and evaluated in piloted, motion-bawd simulation o r through flight test These evaluations have demonstrated the feasibility of automating the NOE flight &ion, and have generated additional spin-off applications of the technologies.