Abstract: A slope landing compensator system for allowing helicopters with air/oil strut type landing gear to land on inclined surfaces while maintaining the air frame in a more upright attitude, comprising two pressure responsive valves, an interconnecting line with a conventional on/off valve between the two valves. A pressure responsive valve is mounted to each of the main landing gear struts with an interconnecting line between the two so that during landing on an inclined surface, as the up slope gear touches the surface and as the strut compresses the internal pressure travels across to the down slope strut until the up slope strut has compressed to a predetermined pressure at which time pressure is sufficient to close the pressure responsive valve of the up slope strut to give firm support and so that all the pressure is not transmitted to the down slope strut and allow the up slope strut to bottom out.

Abstract: The damping coefficient and spring constant of shock absorbing struts for commercial jet aircraft landing gears are selected to allow optimum absorption of forces on the landing gears at touchdown for an aircraft that has been descending at the maximum permissible "sinkrate" (descent rate immediately prior to touchdown). When so selected, the shock absorbing struts are unable to effectively dampen vertical oscillations of the aircraft body ensuing from a downward plunging of the weight of the aircraft due to the deployment of lift spoilers immediately after touchdown.

Abstract: The weight and balance of an aircraft is determined by measuring the pressure of a fluid in a variable volume chamber provided in a piston-cylinder shock absorber assembly of the landing gear strut. In order to minimize axial friction forces in the assembly that introduce errors in an otherwise accurate correlation between the measured fluid pressure and the magnitude of the aircraft load, an existing hollow cylindrical bearing structure, coaxially disposed between the piston and cylinder for guiding reciprocation of the former within the latter, is modified so that it can be rotated about the axis of the assembly. An actuator is provided on the strut for rotating the bearing structure with respect to the cylinder and piston. Such rotation minimizes axial friction forces in the assembly, allowing the fluid pressure to assume a value accurately reflecting the axial load.

Abstract: An aircraft undercarriage includes a liquid filled telescopic suspension strut and a compressed gas chamber separated from the liquid in the strut by a floating piston. Liquid is added to or taken away from the strut by a ride control valve operated by a ride control mechanism sensitive to relative displacement of the airframe and undercarriage wheel so that the aircraft is maintained at a constant height during taxiing. Shut-off valves isolate the strut from the hydraulic system of the aircraft during flight and landing touchdown.