Abstract: In a system having many unequal-area dampers (16) and a common main accumulator (34) for providing positive hydraulic pressure thereto, a shutoff valve (64) and a backup accumulator (62) are provided for each damper (16). In the event of a loss of pressure in the system, the shutoff valve (64) isolates each damper (16) and associated backup accumulator (62) from the rest of the system so that positive hydraulic pressure is provided to each associated damper (16).

Abstract: Centering and stabilizing against rotation of a helicopter swashplate stationary ring are provided by spokes that are attached between the airframe and the stationary ring. When the swashplate tilts for cyclic control, the spokes bend and twist. When the swashplate translates for collective control, the spokes are required to lengthen and skew with respect to the swashplate. An elastomeric bearing having a cylindrical component to allow for skew and a shear pad to allow for lengthening attaches each spoke to the swashplate. The invention eliminates the need for the ball joint, standpipe and scissors associated with traditional swashplate centering techniques.

Abstract: A helicopter rotor blade to hub arm attachment configured to react centrifugal loads from the blade through a blade cuff, spindle, and elastomeric bearings utilizes a bolt in the bore of the spindle for secondary load path operation and a spindle integrity monitoring indicator to provide a visual showing of a deviation from the normal load path.

Abstract: A method and apparatus for using pressure changes to indicate volume chan in fluid level indicators or other devices with the required degree of sensitivity and accuracy is provided. A change in fluid volume is indicated by detection and display of a concurrent pressure change in a captive volume of air.