Abstract: A weight-on-gear sensor for use on an aircraft with landing skids having a bracket and a displacement sensor attached to the bracket is disclosed. The bracket has a center member connecting a first end member to a second end member. The center member has a centerline and the end members extend from the centerline of the center member. Mounting members extend along the centerline of the center member to facilitate attachment of the bracket to a cross tube. The displacement sensor connects the first end member to the second end member. The displacement sensor is parallel to, and offset from, the centerline of the center member so that when a bending moment is applied to the center member the first displacement sensor is either elongated or shortened.

Abstract: A weight-on-gear sensor for use on an aircraft with landing skids having a bracket and a displacement sensor attached to the bracket is disclosed. The bracket has a center member connecting a first end member to a second end member. The center member has a centerline and the end members extend from the centerline of the center member. Mounting members extend along the centerline of the center member to facilitate attachment of the bracket to a cross tube. The displacement sensor connects the first end member to the second end member. The displacement sensor is parallel to, and offset from, the centerline of the center member so that when a bending moment is applied to the center member the first displacement sensor is either elongated or shortened.

Abstract: A weight-on-gear sensor for use on an aircraft with landing skids having a bracket and a displacement sensor attached to the bracket is disclosed. The bracket has a center member connecting a first end member to a second end member. The center member has a centerline and the end members extend from the centerline of the center member. Mounting members extend along the centerline of the center member to facilitate attachment of the bracket to a cross tube. The displacement sensor connects the first end member to the second end member. The displacement sensor is parallel to, and offset from, the centerline of the center member so that when a bending moment is applied to the center member the first displacement sensor is either elongated or shortened.

Abstract: A method and apparatus for tactile cueing of aircraft controls (21) is disclosed. The apparatus of the present invention warns pilots of approaching limits on certain aircraft performance parameters. The most common warnings are for rotor speed exceeding a moving limit. The present invention uses tactile cueing through the collective stick (21). Tactile cueing means that the pilot does not need to scan the intruments to ascertain proximity to the aforementioned limits. Instead, the pilot can operate the aircraft within proper limits by touch, while maintaining situational awareness outside of the cockpit (20). The method and apparatus of the present invention provides customary friction resistance up to a limit position that is continuously updated. According to the present invention, continued motion of the collective (21) in a direction beyond that limit position results in a breakout force and an increasing resistive force.

Abstract: A trim actuator for actuating mechanical controls in an aircraft flight control system in response to signals from a pilot having a stepper motor, a gear train member coupled to the stepper motor, an output member coupled to the gear train member. The trim actuator has a locked mode in which the mechanical controls are held in a fixed position relative to the aircraft, and a non-interference mode in which the mechanical controls are free to be moved by the pilot without interference from the aircraft flight control system. The non-interference mode and the locked mode are both achieved by the stepper motor.

Abstract: An apparatus for interconnection in a helicopter tail rotor control linkage for changing the pitch of the tail rotor blades in response to predetermined inputs is provided. The apparatus comprises a linkage member having a variable geometry, an actuator, and a control unit. In a preferred embodiment, the control unit utilizes a microcontroller to monitor inputs corresponding to ambient air condition and automatically vary the maximum tail rotor pitch so as to provide maximum tail rotor authority over a range of altitudes.

Abstract: A hydraulic inertial vibration isolator is connected between a vibrating body and an isolated body. The vibration isolator comprises a cylinder which includes two chambers and a piston therebetween. The chambers are connected by a tuning passage in which a solid tuning slug is slidably disposed. The chambers and the portion of the tuning passage not occupied by the tuning slug are filled with liquid. Bypass passages connecting the tuning passage to the chambers allow the liquid pressures in the chambers to equalize when the amplitude of the tuning slug's oscillatory motion is sufficiently large, thereby limiting the tuning slug's amplitude. Dashpots axially disposed adjacent to either end of the tuning slug act to damp excessive tuning slug motion and to bias the tuning slug toward the center of the tuning passage.

Abstract: A helicopter mast is driven by a transmission with a swashplate individually linked to pitch horns on each rotor blade. At least four actuators are coupled to the swashplate, three of which normally control the attitude and position of the swashplate. A separate power unit is provided for each actuator, each power unit being independently driven from the transmission. Means are then provided to shift control of the swashplate from one of the three actuators to a fourth actuator upon any one becoming disabled.

Abstract: A finger tip actuated structural crack monitor operation wherein a conductive array is adhered to a structure which is susceptible to development of cracks upon fatigue. An interrogation module is mounted on the structure and is connected to the array with circuit means in the module to sense any momentary discontinuity in the array and to store a failure condition therein upon detection of such discontinuity. A readout means is manually operated to provide a human sensible indication of the existence of the failure condition.