Abstract: A model-following aircraft control system in which a roll rate command in Euler coordinates is integrated to provide a bank angle command, which has actual bank angle subtracted therefrom to provide a command error that is converted back to aircraft body coordinates for use, so long as the pitch attitude of the aircraft does not approach zenith or nadir. But, while the absolute value of the pitch attitude exceeds 85.degree. the last error generated before exceeding 85.degree. is converted to body coordinates for use by the aircraft, and the initial integrated value of attitude command, for use when the pitch angle reverts below 85.degree., is formed as the sum of said last error and the actual attitude angle of the aircraft.

Abstract: The described embodiment of an edge-of-part (EOP) scribe device is operative to simultaneously scribe opposed trim lines in an oversized, cured leading-edge sheath mounted on a sheath mold assembly. The EOP scribe device includes a primary carriage assembly having rollers secured thereto wherein the primary carriage assembly is translatable along side rails secured to the sheath mold assembly, opposed pairs of guide rails affixed to the primary carriage assembly, and a secondary carriage assembly mounted in movable combination with each pair of guide rails. Each secondary carriage assembly includes a spring-loaded scribe head for inscribing a trim line in the cured leading-edge sheath, a rigid follower linkage secured to the secondary carriage assembly, and a follower slide roller mounted in rotatable combination with the rigid follower linkage and operative to rotatably engage a trim line template mounted on the sheath mold assembly.

Abstract: A method for fabricating a composite article having a composite stiffening member co-cure bonded in integral combination therewith wherein the composite article comprises outer mold line (OML) and inner mold line (IML) composite skins and a modified honeycomb core interposed therebetween. The method includes a first set of steps for modifying the honeycomb core of the composite article and includes the steps of providing a detail mold that defines a detail cavity and a core engagement surface, aligning the honeycomb core with the detail mold by abuttingly engaging a first surface of the honeycomb core with the core engagement surface wherein a base segment of the honeycomb core is aligned with the detail cavity, to injecting a RIM foam to fill the detail cavity and the honeycomb cells of the base segment, and curing the injected RIM foam to form the modified honeycomb core that includes a densified base segment and a detail mandrel integral with the densified base segment.

Abstract: An unmanned aerial vehicle (UAV) has a toroidal fuselage and a rotor assembly having a pair of counter-rotating rotors secured in fixed coaxial combination with the toroidal fuselage to provide a vertical takeoff and landing (VTOL) capability for the UAV. One embodiment of the VTOL UAV is especially configured for ground surveillance missions by the inclusion of an externally mounted, remotely controllable stowable sensor subsystem that provides an azimuthal scanning capability and a predetermined elevation/depression scanning capability to accomplish the ground surveillance mission and a foldable landing gear subsystem to facilitate landing of the VTOL UAV at unprepared ground surveillance sites.

Abstract: Apparatus and methods for fabricating a helicopter main rotor blade include a compaction fixture for assembling and compacting blade subassembly components and a sheath spreading/insertion apparatus for spreading and inserting a leading-edge sheath onto the blade subassembly during the compaction process. The compaction fixture includes a lower assembly having a contoured upper airfoil nest mounted in combination with a support structure and an upper assembly having a pressure bag affixed in sealed combination to a contoured backplate affixed in combination to a structural support truss. The contoured upper airfoil nest includes a plurality of tooling pins for locating an upper composite skin in aligned combination on the contoured upper airfoil nest and a plurality of pusher pins for chordwise alignment of a spar assembly in the contoured upper airfoil nest. Spar stanchions affixed to the support structure provide spanwise alignment of the spar assembly in the contoured upper airfoil nest.

Abstract: A hybrid panel fastener for use in conjunction with a nut and cage assembly for fastening and unfastening a composite access panel that is galvanically compatible with the composite access panel, suitable for low observability applications, and high cycle usage includes a composite shank member and a metallic sleeve member integrated in combination. The composite shank member includes an interface segment having a peripheral engagement surface, a body segment contiguous with the interface segment, and a head having a torque-input surface contiguous with the body segment. The metallic sleeve member has an externally threaded surface and an integration bore that is complementary to the peripheral engagement surface of the interface segment.

Abstract: A duct cover for use with a duct within a vehicle, the duct cover operative for directing a fluid flow. The duct cover being further operative for minimizing the entrance of foreign object debris into the duct. The duct cover has a flow directing honeycomb portion for conducting the passing fluid flow in a preferred direction. The flow directing honeycomb comprises an array of continuous, polygon shaped open cells which are biased with respect to the initial fluid flow direction. The periphery of the flow directing honeycomb is rigidized to stiffen the same for minimizing the displacements thereof. The rigidity is provided by a framing member comprising upper and lower skin structures affixed to a core material. The framing member is preferably adhesively bonded to the flow directing honeycomb by means of a foaming adhesive and a barrier member. The barrier member is operative for minimizing the expansion of the foaming adhesive into the open cells of the honeycomb.

Abstract: A shock strut assembly for an aircraft landing gear includes a trunnion fitting, a compressible oleo strut subassembly, a wheel subassembly, an energy dissipating subassembly, and a mechanical load control subassembly. The oleo strut subassembly includes a cylinder member having an upper end mounted in combination with the trunnion fitting by means of the mechanical load control subassembly and a piston member having a lower end affixed in combination with the wheel subassembly and an upper end slidably inserted in the cylinder member. The energy dissipating subassembly includes a cylindrical cutter member secured in combination with the cylinder member and the trunnion fitting and a frangible tube member mounted in concentric combination with the cylinder member so that the lip of the upper end thereof is disposed in abutting engagement with the cutter member.

Abstract: An aircraft duplex hinge assembly (10 or 10') configured for use in aircraft, especially helicopters, having a compound curvature airframe (130) configuration wherein the edges of access panels (100) and the corresponding airframe apertures have a beveled configuration. The duplex hinge assembly (10 or 10') includes dual hinge mechanisms (20) and a latching mechanism (50) to deactivate the duplex hinge mechanism (10) with the access panel (100) in the closed position. The dual hinge mechanisms (20) include a primary mounting bracket (22) secured in combination with the airframe (130), a secondary mounting bracket (24) secured in combination with the access panel (100), and an interconnecting member (26) having a straight segment (30), an arcuate segment (32), and a protective flat segment (34).

Abstract: An engineered ceramic component for the leading edge of a rotor blade provides enhanced erosion protection therefor. In one embodiment, the engineered ceramic component includes a strain isolator member, an aerodynamic ceramic member, a first adhesive bond layer, and a second adhesive bond layer. The strain isolator member, which is operative to minimize strain transfer between the rotor blade infrastructure and the aerodynamic ceramic member, is configured so that inner mold line surface thereof is complementary to outer mold line surface of the rotor blade infrastructure. The aerodynamic ceramic member, which is operative to provide enhanced erosion protection for the respective leading edge of the rotor blade, is configured so that the outer mold line surface thereof defines the aerodynamic configuration of the respective leading edge and the inner mold line surface is complementary to the outer mold line surface of the strain isolator member.

Abstract: A method for fabricating a helicopter main rotor blade includes a compaction fixture for assembling and compacting blade subassembly components and a sheath spreading/insertion apparatus for spreading and inserting a leading-edge sheath onto the blade subassembly during the compaction process. The compaction fixture includes a lower assembly having a contoured upper airfoil nest mounted in combination with a support structure and an upper assembly having a pressure bag affixed in sealed combination to a contoured backplate affixed in combination to a structural support truss. The contoured upper airfoil nest includes a plurality of tooling pins for locating an upper composite skin in aligned combination on the contoured upper airfoil nest and a plurality of pusher pins for chordwise alignment of a spar assembly in the contoured upper airfoil nest. Spar stanchions affixed to the support structure provide spanwise alignment of the spar assembly in the contoured upper airfoil nest.

Abstract: A method for high pressure co-cure molding of lightweight honeycomb core composite articles having ramped surfaces utilizing low total density, stabilized ramped honeycomb cores. The low total density, stabilized ramped honeycomb core is formed by net shaping stabilized honeycomb core material into a ramped honeycomb core, which is prepped for lay-up and co-cure by applying a layer of low areal weight film adhesive to the upper, lower and ramped surfaces thereof. The honeycomb core material is stabilized for the net shaping operation by a layer of the low areal weight film adhesive applied to the upper and lower surfaces of the material in a predetermined picture frame format. Composite prepregs and the ramped honeycomb core are layed-up in a semi-rigid molding assembly including a rigid base member and a complementary semi-rigid mold member having at least one internal rigid reinforcement insert, which is vacuum bagged and disposed in an autoclave.

Abstract: A two-stage co-cure method for fabricating a composite article having a box-beam cross-sectional configuration wherein an outer shell portion of the composite article is fabricated and configured in the first stage to function as the tooling for completing the fabrication of composite article in the second stage.

Abstract: One broad-beam ion deposition coating method (10) for depositing diamond-like-carbon (DLC) coatings (124) on the dynamic surfaces (120S) of articles (120) subject to adherence difficulties includes the steps of: (12) preliminarily conditioning the dynamic surface (120S) for broad-beam ion deposition; (14)inserting the article (120) in a deposition chamber (102); (16) evacuating the deposition chamber (102) to a predetermined base pressure; (18) ion sputtering conditioning of the dynamic surface (120) by ionizing an inert gas to form an ion beam (104B) having a predetermined beam current density and accelerating energy and directing the ion beam (104B) onto the dynamic surface; (20) depositing an interface layer (122) on the dynamic surface (120S) by ionizing a first gas to form an ion beam (104B) having a predetermined beam current density and accelerating energy, and directing the ion beam (104B) onto a target (118) to dislodge atoms therefrom, the dislodged atoms depositing on the dynamic surface (120S) to

Abstract: A stacked compound planetary gear train for an upgraded powertrain system for a helicopter that provides an increased reduction ratio to accommodate the increased horsepower output of the augmented powerplant system while concomitantly providing a baseline RPM output to the main rotor shaft. The stacked compound planetary gear train includes a driving sun gear, a set N of primary planetary pinions, a plurality of secondary planetary pinions, a compound drive shaft supporting each respective primary and secondary planetary pinion combination, a fixed ring gear interacting with the secondary planetary pinions, and a planetary carrier assembly disposed in rotatable combination with the compound drive shafts and operative to provide the output of the stacked compound planetary gear train to the main rotor shaft of the helicopter. The set N of primary planetary pinions includes a plurality N/2 of upper primary planetary pinions and a plurality N/2 of lower primary planetary pinions.

Abstract: A flexible engine inlet duct mounting system for integrating an engine inlet duct in combination with an engine system to minimize or eliminate turbulence-inducing structural discontinuities therebetween wherein non-turbulent intake airflow is provided to the engine system. The mounting system includes a mechanical support assembly that constrains the relative motion between the aft ends of the inlet duct and the engine system, and a dual seal assembly that accommodates such relative motion while concomitantly maintaining seals between the inlet duct and the engine system. The duct support assembly includes an annular duct support member and an annular spherical adaptor member having interacting ends that have complementary arcuate configurations which constrain the relative motion of the aft ends of the inlet duct to in-plane displacements about a duct pivot point coincident with the engine system centerline.

Abstract: A crashworthy cyclic control stick system (10) for use in combination with an energy attenuating stroking crew seat (100) includes a cyclic control stick (11) and an actuating/attenuating mechanism (50). The cyclic control stick (11) includes an upper tube subassembly (14U) having a first hinge fitting (22), a lower tube subassembly (14L) having a second hinge fitting (24), the first hinge fitting (22) being mounted in pivotable combination with the second hinge fitting (24) along a hinge pivot axis (26) the and a locking mechanism (30) mounted in pivotable combination with the first hinge fitting (22) and interactively connected to the second hinge fitting (24) to preclude pivotal movement between the hinge fittings (22, 24).

Abstract: A hybrid composite flexbeam for a soft inplane bearingless main rotor assembly has eight spanwise regions: a hub attachment region; a first tapered region; a second tapered region; an inboard transition region; a pitch region having a cruciform configuration; an outboard transition region; a tapered outboard transition region; and a main rotor blade, torque tube attachment region. The pitch region is formed from unidirectional fiberglass plies, a 50/50 admixture of unidirectional fiberglass and graphite plies, and unidirectional graphite plies, all of which extend from root to tip of the hybrid flexbeam. Unidirectional fiberglass and graphite plies of varying lengths are interleaved in the second inboard tapered region. Fiberglass and graphite cross plies of varying lengths are interleaved in the first inboard tapered region. Fiberglass and graphite cross plies and unidirectional fiberglass plies of varying length are interleaved in the outboard tapered region.

Abstract: An apparatus for fabricating a helicopter main rotor blade includes a compaction fixture for assembling and compacting blade subassembly components and a sheath spreading/insertion apparatus for spreading and inserting a leading-edge sheath onto the blade subassembly during the compaction process. The compaction fixture includes a lower assembly having a contoured upper airfoil nest mounted in combination with a support structure and an upper assembly having a pressure bag affixed in sealed combination to a contoured backplate affixed in combination to a structural support truss. With the upper and lower assemblies in locked combination, the pressure bag is pressurized to compact the assembled blade subassembly components. The sheath spreading/insertion apparatus includes a movable stanchion, upper and lower elongate carriage members mounted in synchronized movable combination with the stanchion, and a row of suction cups mounted in combination with each carriage member.