An Automatic Landing System

The concept, theory, implementation, and test results of the Bell Aircraft Automatic Landing System are presented. The system, which requires no additional airborne electronics equipment in land-based aircraft carrying an ILAS receiver and coupler, employs a precise ground-based radar and command computer. The major source of error of this closed-loop system is turbulence, while performance is limited chiefly by aircraft and autopilot properties. Flight-test results covering over 2000 automatic touchdowns and a variety of propeller and jet aircraft are presented for vertical and lateral degrees of freedom.