Abstract: A method and apparatus for controlling lateral vibration in a rotating shaft, wherein the lateral vibration is controlled through the disposition of a mass having a predetermined weight in combination with the rotating shaft such that the first order critical frequency of the shaft is decreased below an operating frequency range for the rotating shaft. The mass is disposed in combination with the shaft at a second order critical frequency node such that the disposition of the mass does not decrease the second order critical frequency.

Abstract: A system and method for automatically controlling cabin air temperature T.sub.CBN in an aircraft having a cabin and a mixed air delivery system. The mixed air delivery system provides a flow of mixed air having an actual mixed air temperature into the cabin. The mixed air delivery system comprises a hot bleed air sub-system for providing a flow of hot bleed air, a cool air sub-system for providing a flow of cool air, and an ambient air sub-system for providing a flow of ambient air. The method comprises the steps of defining a selected cabin air temperature T.sub.CBN SEL, and then controlling the flow of hot bleed air, the flow of cool air, and the flow of ambient air such that the mixed air temperature is driven toward a target mixed air temperature defined as k(T.sub.CBN SEL -T.sub.CBN)+T.sub.CBN SEL, wherein k is a gain factor.

Abstract: A method and apparatus for controlling the thickness of press-cured composite articles during the manufacture thereof. The method includes a preparatory or prefabrication stage wherein prepreg plies are layed up and compacted to form a plurality of laminates that define a final laminate package that defines the uncured configuration of the composite article. The final laminate package may include supplemental ply-packs layed up at the mid-plane or neutral axis of the final laminate package for the purpose of controlling the overall thickness of the final laminate package. The prepreg plies layed up in the preparatory stage have been precut to conform to the final net shape of the composite article, but include a predetermined overbuild in the width dimension to facilitate control of thickness during cure of the final laminate package.

Abstract: A monitoring and control system for a dual-engine helicopter for OEI flight operations includes a parametric indicator operative in response to sensor signals for monitoring an engine gas generator speed parameter N1 during dual-engine and OEI flight operations. The indicator includes a rotatable needle that provides an analog indication of the current value of the N1 parameter. For dual-engine flight operations, the indicator includes a first DE indicia defining a normal operating range for the N1 parameter, a second DE indicia that defines a precautionary operating range for the N1 parameter, and a DE indicium that defines a take off power limit for the N1 parameter.

Abstract: A composite tip cap assembly for a helicopter main rotor blade includes a composite main fairing, a unitary composite rib detail internally integrated in combination with the composite main fairing, a composite closure fairing bonded in combination with the composite main fairing, and an abrasion strip bonded in combination with the composite main fairing and the composite closure fairing.

Abstract: A system and method for conducting one engine inoperative (OEI) flight procedures training in a dual-engine helicopter includes a multi-function OEI training switch that is operative to initiate OEI flight procedures training by selecting one of said engines as the single operative engine for OEI flight procedures training, and a training function module that is: (1) operative to establish suppressed 30-second, 2-minute, and maximum continuous OEI operating limits for selected engine operating parameters to limit the actual power provided by said powerplant system during OEI flight procedures training; and (2) operative to generate biasing factors to control the operation of the parametric indicators for the selected engine operating parameters during OEI flight procedures training.

Abstract: A collective detent system is incorporated in combination with the flight control system of a helicopter to enhance vertical takeoff flight operations of the helicopter.

Abstract: One embodiment of a mechanical emergency dual-release mechanism for use in combination with a helicopter external cargo hook system that includes a cargo hook assembly that is operative to jettison an externally-attached cargo includes an interface member for mounting the dual-release mechanism in rigid combination with the cargo hook assembly, a pulley axle mounted in rigid combination with the interface member, a cockpit pulley assembly mounted in rotatable combination with the pulley axle, a cabin pulley assembly mounted in rotatable combination with the pulley axle, and a displacement transfer member that operatively interconnects the cockpit pulley assembly and the cabin pulley assembly. The cabin pulley assembly is functionally interconnected to the cargo hook assembly and operative in response to a mechanical stimulus generated by means of the cockpit pulley assembly or the cabin pulley assembly to activate the cargo hook assembly to jettison the externally-attached cargo.

Abstract: A virtual image display system for aircraft is operative to identify threat systems that are proximal the flight path of an aircraft when the aircraft is within the threat range of such threat systems. The virtual image display system is further operative to generate three-dimensional threat envelopes of identified threat systems and to display real-time perspective video images of such three-dimensional threat envelopes for viewing by the pilot.

Abstract: A method for fabricating a split path transmission system that achieves equal torque splitting between the forward and aft split load paths of each gear train thereof at a predefined operating point by providing an intentional timing difference between gears and pinions of the forward and aft split load paths of each gear train of the split path transmission system is disclosed. The method includes the steps of identifying the torque distribution curves of the forward and aft split load paths of one gear train of the split path transmission system. The method further includes a step of selecting a predefined operating point for the split path transmission system wherein equal torque splitting between the forward and aft split load paths of the one gear train is desired. Next, the forward and aft torque distribution curves are analytically modified as required to pass through the predefined operating point.

Abstract: A precision center for mounting a workpiece for precision machining thereof includes a modified head center, an actuating assembly, a drive assembly, and a double-arcuate floating collet. The actuating assembly is mounted within the modified head center and operative to generate an actuating force. The drive assembly is mounted within the modified head center, is mechanically coupled in combination with the actuating assembly, and is operative in response to the actuating force to generate a drive force.

Abstract: A blade-mounted total pressure (BMTP) probe for a rotor blade comprises a base segment and an inlet segment. The base segment includes an interface surface having a planar configuration that is complementary to an aerodynamic surface of the rotor blade for detachably mounting the BMTP probe in combination with the rotor blade, an aerodynamically-streamlined body member contiguous with the interface surface that includes a leading edge and first and second flow surfaces, and a fluid communication aperture extending through the aerodynamically-streamlined body member and the interface surface. The inlet segment comprises an inlet defined by a lower wall contiguous with the aerodynamically-streamlined member, opposed sidewalls contiguous with the lower wall, and an upper wall contiguous with the opposed sidewalls.

Abstract: In one embodiment for a helicopter main rotor assembly, a half-plow vortex generator is mounted in combination with the upper aerodynamic surface of each main rotor blade and is operative to generate a primary corotating vortex of sufficient strength to interact with and accelerate the dissipation of the tip vortex generated by the same main rotor blade, thereby reducing blade-vortex interaction noise radiating from the helicopter main rotor assembly. The half-plow vortex generator has a right triangular planform configuration defined by a length, a width, and an apex angle. The three-dimensional configuration of the vortex generator is further defined by an apex height. The apex height is the primary determinant of the strength of the generated primary corotating vortex and is defined in terms of the thickness of the main rotor blade at the local chord where the vortex generator is mounted.

Abstract: In one embodiment for a helicopter main rotor assembly, a half-plow vortex generator is mounted in combination with the upper aerodynamic surface of each main rotor blade and is operative to generate a primary corotating vortex of sufficient strength to interact with and dissipate the tip vortex generated by the same main rotor blade, thereby reducing blade-vortex interaction noise radiating from the helicopter main rotor assembly. The half-plow vortex generator has a right triangular planform configuration defined by a length, a width, and an apex angle. The three-dimensional configuration of the vortex generator is further defined by an apex height. The apex height is the primary determinant of the strength of the generated primary corotating vortex and is defined in terms of the magnitude of the local chord where the vortex generator is mounted. The apex height preferably has a magnitude within the range of about 0.01 to about 0.08 of the magnitude of the local chord.

Abstract: A low profile latch mechanism for an access panel that minimizes external structural discontinuities while concomitantly providing external access to engage and/or disengage the latch mechanism for closing and/or opening of the access panel. The latch mechanism includes an insert member mounted in rotatable combination with the internal surface of the access panel, a captured floating nut mounted in nonrotatable combination with the internal surface of a frame segment, a safety lock member mounted for axial displacement within the captured floating nut, and a removable key member. The removable key member is insertable through an access aperture in the access panel to engage the insert member for rotation thereof to threadingly engage the captured floating nut to close the access panel. The safety lock member is biased to engage the insert member to lock the low profile latch mechanism in the fully engaged state upon removal of the key member.

Abstract: An aerodynamic-electrostatic particulate collection system for high-efficiency collection of particulate debris generated in a machining area during machining of a workpiece, especially post-cure machining of a composite workpiece, that includes a vacuum subsystem for generating a localized, vacuum-induced aerodynamic fluid flow field in the machining area and a particulate charging, electric field generating subsystem integrated in combination with the workpiece and the vacuum subsystem for charging particulate debris generated during machining of the workpiece and for creating an electric field that directs the charged particulate debris into the localized, vacuum-induced aerodynamic fluid flow field. The vacuum subsystem includes a vacuum pump, a hose fluidically interconnected to the vacuum pump, and a nozzle fluidically connected to the hose distal the vacuum pump and having a configuration that defines the localized, vacuum-induced aerodynamic fluid flow field.

Abstract: A method and apparatus for controlling the thickness of press-cured composite articles during the manufacture thereof. The method includes a preparatory or prefabrication stage wherein prepreg plies are layed up and compacted to form a plurality of laminates that define a final laminate package that defines the uncured configuration of the composite article. The final laminate package may include supplemental ply-packs layed up at the mid-plane or neutral axis of the final laminate package for the purpose of controlling the overall thickness of the final laminate package. The prepreg plies layed up in the preparatory stage have been precut to conform to the final net shape of the composite article, but include a predetermined overbuild in the width dimension to facilitate control of thickness during cure of the final laminate package.

Abstract: A method of fabricating a low total density, stabilized ramped honeycomb core for high pressure co-cure molding of a lightweight honeycomb core composite article includes forming the honeycomb core by net shaping stabilized honeycomb core material into a ramped honeycomb core. The ramped honeycomb core is prepared for lay-up and co-cure by applying a layer of low areal weight film adhesive to the upper and lower surfaces and to each ramped surface of the ramped honeycomb core. The honeycomb core material is stabilized for the net shaping operation by applying a layer of low areal weight film adhesive to the upper and lower surfaces of the honeycomb core material in a predetermined picture frame format.

Abstract: A zero clearance locking mechanism for a disconnect coupling device for a segmented driveshaft wherein the disconnect coupling device includes an input disconnect member having an input splined coupler integrated in combination therewith, an output disconnect member having an output splined coupler integrated in combination therewith, and a coil spring disposed in combination with the input disconnect member and operative to provide a biasing force.

Abstract: An aerodynamic-electrostatic particulate collection system for high-efficiency collection of particulate debris generated in a machining area during machining of a workpiece, especially post-cure machining of a composite workpeice, that includes a vacuum subsystem for generating a localized, vacuum-induced aerodynamic fluid flow field in the machining area and a particulate charging, electric field generating subsystem integrated in combination with the workpiece and the vacuum subsystem for charging particulate debris generated during machining of the workpiece and for creating an electric field that directs the charged particulate debris into the localized, vacuum-induced aerodynamic fluid flow field. The vacuum subsystem includes a vacuum pump, a hose fluidically interconnected to the vacuum pump, and a nozzle fluidically connected to the hose distal the vacuum pump and having a configuration that defines the localized, vacuum-induced aerodynamic fluid flow field.