Abstract: A composite lug assembly includes a composite lug defining a loaded side and an unloaded side and having at least one hole extending therebetween, a shoulder bushing assembly including a first side bushing having a first cylindrical portion adapted to fit in the hole and a first shoulder portion extending from the first cylindrical portion and a second side bushing having a second cylindrical portion adapted to fit within the first cylindrical portion and a second shoulder portion extending from the second cylindrical portion wherein the first side bushing is made of a different material than the second side bushing.

Abstract: In a method for reducing sensed physical variables generating a plurality of control commands are generated at a control rate as a function of the sensed physical variables. An estimate of a relationship between the sensed physical variables and the control commands is also is used in generating the plurality of control commands. The estimate of the relationship is updated based upon a response by the sensed physical variables to the control commands. The generation of the control commands involves a quadratic dependency on the estimate of the relationship and the quadratic dependency is updated based on the update to the estimate.

Abstract: A drag reduction system extends from an underside of a VTOL aircraft forward of a four-point sling system. The four-point sling system carries an external load close to an underside of the airframe and oriented along the aircraft longitudinal axis. The drag reduction system includes a retractable shield mounted beneath the underside of the aircraft which reduces drag of the external sling load and reduces the airloads on the external load.

Abstract: A rotor blade assembly provides a pitch control assembly to pitch the rotor blade about a rotor blade pitch axis. The pitch control assembly includes a trailing edge flap and a trailing edge servo flap that extend from the trailing edge of the rotor blade. The trailing edge flap is offset in the span wise direction relative to the trailing edge flap. The trailing edge servo flap is located upon a trailing edge servo flap arm linked to the trailing edge flap. To pitch the rotor blade, the trailing edge servo flap is pitched in a direction opposite the desired pitch direction of the trailing edge flap.

Abstract: A main rotor blade includes a tip section having a splice cap, a structural tip spar, a core and an upper and lower tip skin. The tip section is mounted to a central blade section by mounting the tip spar to a main blade spar. The tip spar includes a first surface substantially parallel to a second surface. The first and second surfaces each extend from a shear web therebetween to define the generally C-shape in cross section. The shear web generally carries rotor blade torsional loads and eliminates the heretofore required structural core. A section of the tip spar overlaps a section of the main blade spar. The tip section thereby transfers the loads carried thereby through interaction between the overlapped spar sections. The tip section core and skins need not be structural members as the tip spar carries rotor blade tip section torsional loads.

Abstract: A rotor blade assembly system includes a trim tab assembly which utilizes relatively thick resilient members bonded between a trim tab and the two trim tab doublers. Spanwise segmenting of the tab and the use of thick resilient member isolates the trim tab from normal strain. Because the trim tab is made of aluminum, the tab can be readily adjusted the field using a conventional tool.

Abstract: A Rotary Air-data System (RADS) periodically samples pressure data from a main rotor blade mounted pitot-scoop integrated with a high accuracy pressure sensor to compute a velocity vector that is resolvable into the aircraft's coordinate system. Mathematical techniques are employed which provide accurate computations of static pressure without a static pressure sensor. The RADS also computes the direction of the relative wind which is particularly useful when the pilot executes hover or low speed, low altitude maneuvers in restricted visibility. The availability of relative wind velocity information coupled with navigation data enhances the ability of rotary aircraft to perform accurate low altitude hover, fire control and other autopilot maneuvers.

Abstract: A multi-element rotor blade includes an individually controllable main element and fixed aerodynamic surface in an aerodynamically efficient location relative to the main element. The main element is controlled to locate the fixed aerodynamic surface in a position to increase lift and/or reduce drag upon the main element at various azimuthal positions during rotation.

Abstract: A method for improving acoustic and vibrational properties of gears includes determining the transmission errors of intermeshing gears due to stiffness variations in the gear teeth, performing Gear Tooth Topological (GTT) modifications to compensate for the errors, and isotropically processing the gears to produce an ultra-smooth surface finish. Additional errors from isotropic processing, machining, loading, thermal effects and/or load sharing may be summed with the errors from the stiffness variations and used for the GTT modifications. The teachings of the present invention may reduce noise by as much as 13 to 15 dB.

Abstract: A rotor system includes a hydraulic pressure system located within a rotor shaft along an axis or rotation. The hydraulic pressure system is within the rotating field such that fluid pressure is generated and supplied from within the rotational field without the need to cross a rotational interface. Differential rotation between the rotor shaft and a standpipe rotates a hydraulic pump body relative a hydraulic pump shaft. The hydraulic pressure system is contained within a support structure so as to be readily mounted and removed from the rotor hub for replacement or maintenance. A gear system is mounted to the support structure between the standpipe and the hydraulic pump shaft to step-up or step-down the relative rotation between the rotor shaft and the standpipe.

Abstract: A powerplant system for a vehicle such as a hybrid UAV includes a miniature gas turbine engine and a gearbox assembly. The engine is mounted to the gearbox assembly through a support structure which provides for pivotal movement of the engine relative thereto. The input gear is engaged with two gears such that the pivoted engine arrangement permits the input gear to float until gear loads between the input gear and the first and second gear are balanced. Regardless of the gear teeth errors or gearbox shaft misalignments the input gear will float and split the torque between the two gears.

Abstract: A surface processing method and power transmission component includes refining a surface region of a metal from a first roughness to a second roughness less than the first roughness. A solid lubricous coating or a hard coating is then deposited on the surface region. The metal has a surface hardness above 50 Rc to reduce the risk that the metal will deform under the coating and leave the coating unsupported. The surface region of the metal may be transformed into a nitrogen-containing compound or solid solution surface region before the surface refining step and deposition of the coating.

Abstract: An active vibration control system provides a mass which is movable through a large excursion while minimizing the system size in two of three dimensions to compensate for sensed vibrations. A first rotating member is rotatable about a first axis and a second rotating member is rotatable about a second axis to drive a belt mounting a mass. The first axis is offset from the second axis such that as the members are rotated, the belt is driven about an elongated path. This arrangement generates an impulsive vibratory force as the mass passes over each of the rotating members and quickly changes direction. A belt including a sinusoidal mass distribution generates a vibratory force that is a smooth sinusoidal output. Multiple systems are suitably usable in conjunction with one another to provide a wide range of vibratory outputs.

Abstract: A non-ferrous component comprising a thermally-affected adhesive applied to a surface of the component, and at least one ferrous metal wire attached to the surface of the component by the thermally-affected adhesive.

Abstract: A noise or vibration control system improves the quality of adaptation estimates by filtering the input signals to the adaptation, selectively implementing a “dead-zone” during which adaptation does not occur and by selectively adding a dither signal to the control commands. The dead-zone is based on the magnitude of the changes in the control commands, which are responding to the changes in the sensor signals. The dead-zone can be applied to all actuators simultaneously, or can be applied to the adaptation of each actuator channel independently. To maintain identifiability, a “dither signal” is added to the control commands to “ping” the system to increase the amount of information available to the adaptive algorithm. The dither signal is preferably implemented on only one actuator channel at a time. Also, the dither amplitude for each channel is preferably set to be proportional to the current control amplitude.

Abstract: The present invention relates to a spacer arrangement used in a duplex bearing system. The spacer arrangement has a lubricant chamber, a first spacer element within the lubricant chamber having a centrifugal ramp, and a second spacer element within the lubricant chamber having a baffle. The baffle divides the lubricant chamber into first and second chambers with each chamber communicating with one of the bearings in the duplex bearing system. The centrifugal ramp counteracts the effects of gravity and uses centrifugal forces to insure a supply of lubricant to one of the bearings, typically an upper bearing, in the duplex bearing system. The spacer arrangement has particular utility in a swashplate assembly used in helicopters, which swashplate assembly includes a stationary swashplate and a rotating swashplate with the duplex bearing arrangement being located between the two swashplates.

Abstract: A snubber inner member has a doubly convex outer surface portion having a central longitudinal axis. A shim/spacer stack secured to the outer surface portion couples the snubber inner member to the second member. A retainer having one or more engagement surfaces cooperates with one or more engagement surfaces of the snubber inner member to constrain lateral movement of the snubber inner member relative to the retainer while permitting longitudinal movement of the snubber inner member away from the retainer. An elastomer secures the retainer to the first member.

Abstract: An aircraft heating system taps into a bleed air flowpath between a turbine engine and an external bleed air port on the aircraft. A system may be installed as a retrofit for heating the cabin of an aircraft already having a heating system for heating the cockpit.

Abstract: A leading edge slat for multi-element rotor blade applications which provide multiple benefits and provide design direction which has heretofore been unexplored.