Abstract: Main rotor pitch control rod assemblies on helicopters constitute means for ranslating an aviator's control impulses in the cockpit to the main rotor blades. Pitch control rod assemblies typically include means for locking the assembly into a predetermined attitude setting. The setting may be held by locking nuts. This invention provides a passive locking means using spring tension to maintain the desired setting if the locking nuts loosen due to stress loads or improper torquing during maintenance. The invention also provides passive means for maintaining expansive stress within the control rod to prevent distortion of the assembly under compressive loads.

Abstract: A Doppler radar system in which quadrature Doppler signals are derived to eld directional information. The quadrature signals are derived by demodulating the return signals with respective odd and even harmonics of the sinusoidal signal used to frequency modulate the RF carrier.