Abstract : Results are presented from an investigation of the load distribution to the main azimuth bearing of the AN/FPS-24 radar. The bearing is a 10-ft diameter 4-point contact bearing subjected to thrust, radial, and overturning loads. Actual static ball loads were determined in a field test. Bearing life calculations based on the measured loads and compared with theoretical calculations are presented. The feasibility of making dynamic measurements of ball loads under actual rotation condition was proven.