Abstract: A method of selecting the optimum mix of resources for achieving an outcome while minimizing risk is presented. In one embodiment, the method is applied to selecting the optimum mix of manufacturing technologies and amount of use of each technology for fabricating a helicopter fuselage structure in order to minimize the recurring cost and keep the risk below a pre-selected value. The method involves selecting a plurality of resources which can be used to achieve the desired outcome. Determining an associated outcome for each resource. Establishing at least one target risk level for the desired outcome. Calculating an associated outcome and risk for a plurality of combinations of the resources at a plurality of percentage applications of each resource. Then determining an optimum mix of resources and percentage of application of each resource which maximizes the outcome while maintaining the risk below the at least one target risk level.

Abstract: A variable diameter rotor blade assembly includes a rotor hub with multiple rotor blades each having an outboard blade section telescopically mounted to an inboard blade section. A reeling assembly includes a strap drum that extends and retracts a strap attached to each of the outboard blade sections to selectively change the diameter of the rotor blade assembly. The strap includes a body portion extending toward the drum and a termination portion attached to each of the outboard blade sections. The termination portion is made from a rigid fiber reinforced composite that has a higher rigidity than the body portion. A transition region is formed between the body portion and the termination portion and is made from a flexible matrix-fiber composite that has a higher rigidity than the body portion and a lower rigidity than the rigid fiber reinforced composite.

Abstract: A cooling system for a hybrid aircraft includes an inlet which extends through the body to communicate airflow to a powerplant subsystem and out through an exhaust within a rotor duct. In a hover mode, there is a significant low-pressure area created inside the rotor duct by the rotor system. The low-pressure area within the rotor duct assists in drawing air through the inlet and over the engine via the exhaust. A cooling fan is located adjacent the inlet to augment cooling-air flow. The cooling fan is smaller than conventional practice because it does not have to provide the entire pressure difference to force air-cooling flow over the engine. In a transition mode, the low-pressure area created inside the rotor duct decreases but ram air pressure through the inlet increases. In a forward flight mode, the pressure inside the rotor duct is approximately atmospheric but significant ram air is provided from the inlet due to forward flight speed.

Abstract: A conformal bearing assembly includes an bearing housing, an elastomeric member and a bearing element. The bearing assembly is mounted between and inner and outer telescopic member. The elastomeric member allows the bearing element to substantially conform to the adjacent telescopic member irrespective of minor manufacturing inconsistencies along the adjacent telescopic member. Contact pressure between the bearing element and the adjacent telescopic member is thereby more evenly distributed which minimizes regions of interference and or clearance which may otherwise result in undesirable wear characteristics of the telescopic system.

Abstract: A method for automating a takeoff maneuver for an aircraft, comprising the steps of generating a takeoff profile comprising a takeoff point, a flight path, and a takeoff decision point (TDP), engaging an automated takeoff system to access the takeoff profile, receiving periodic position data of the aircraft, comparing the position data to the takeoff profile to compute a plurality of deviations each time the position data is received, outputting the plurality of deviations to a display, converting the plurality of deviations into a plurality of control commands, and maneuvering the aircraft in response to the control commands along the flight path.

Abstract: An alignment device mounts to a missile system such that the view of a missile seeker is limited to limited fields of view at predetermined positions relative to a known reference such as the missile centerline. Once the alignment device is mounted to the missile system, an energy source emitting energy viewable by the seeker is located within a field of view. Once the seeker has locked-on to the energy source in a limited field of view, the pointing angle of the seeker can be observed by a measurement device communicating with the missile controller. Any pointing angle observed by the measurement device which differs from the known position defined by the alignment device, represents a displacement error of the seeker. Appropriate compensation is then applied to the missile controller such that alignment errors are accounted for.

Abstract: A main rotor support structure assembly includes a support housing which transmits loads developed by the main rotor assembly into the airframe. Integral main rotor servo attachment lugs extend from the cylindrical body member to provide lower attachment points for the rotor servo actuators which are operable to articulate a rotor swash plate or the like. The servo attachment lugs are integrally formed as part of the cylindrical body member and spaced thereabout. A substantially L-shaped metallic insert is sandwiched and bonded within each servo attachment lug to resist axial and transverse tension of the rather high forces exerted by the rotor servo actuators.

Abstract: A system and method for issuing an aircraft drift advisory. In one embodiment, the system includes a head or eye tracker to monitor the rotational position of the pilot's line of sight with respect to the aircraft axis. The pilot's line of sight is compared to the direction of the aircraft. If the absolute value of the difference is greater than or equal to a predetermined angle, corresponding to the foveal cone of vision, the incremental aircraft drift distance is computed and used to update the cumulative aircraft drift distance. The cumulative aircraft drift distance is compared to the predetermined advisory criterion, which may be a constant, a uniform function of altitude or a function of altitude that is tied to a digital terrain map. When the cumulative aircraft drift distance equals or exceeds the advisory criterion, the pilot is given a drift advisory that the aircraft has drifted so as to prompt the pilot to adjust his line of sight to the direction of the drift.

Abstract: A flight control system includes a blending algorithm which evaluates the current flight regime and determines the effectiveness of the flight controls to effect the rotational moment of a hybrid vehicle about the yaw axis. Gain schedules for both differential collective and rudder control provide a quantitative measure of control effectiveness. Based on the respective gain schedules, the algorithm determines how much of the control commands should be sent to each control surface. The result is that for a given control command, the same amount of yaw moment will be generated regardless of flight regime. This simplifies the underlying flight control law since the commands it generates are correct regardless of flight regime.

Abstract: A flight control system includes a blending algorithm which evaluates the current flight regime and determines the effectiveness of the flight controls to effect the rotational moment of a hybrid vehicle about the pitch axis. Gain schedules for both pitch cyclic and elevator control provide a quantitative measure of control effectiveness. Based on the respective gain schedules, the algorithm determines how much of the control commands should be sent to each control surface. The result is that for a given control command, the same amount of pitch moment will be generated regardless of flight regime. This simplifies the underlying flight control law since the commands it generates are correct regardless of flight regime.

Abstract: A method and apparatus for producing a composite component having a variable thickness includes placing a caul member over a plurality of laid-up prepreg plies supported by a mold and curing the lay-up in an autoclave. The mold includes a cavity for receiving the lay-up that is defined by a bottom surface, a plurality of walls extending upwardly from the bottom surface, and an open upper face surrounded by a mold edge. A support flange extends inwardly toward the center of the cavity from each of the walls at a predetermined distance upward from the bottom surface. The predetermined distance varies along the length of the mold and generally conforms to the outer profile of the composite component to be fabricated. The caul is positioned over the lay-up and defines a longitudinal axis extending along the length of the caul and a lateral axis extending along the width of the caul.

Abstract: A drive system for a variable diameter rotor system includes a plurality of rotor blade assemblies with inner and outer blade segments. The outer blade segment being telescopically mounted to the inner blade segment. The VDR retraction/extension system includes a reeling system driven by a harmonic gear system. The reeling system includes a strap drum for winding and unwinding a strap attached to the outer blade segments. In operation, a control shaft drives the wave generator at a higher or lower rotational speed relative to a main rotor drive shaft assembly thereby causing the wave generator to rotate relative to the rotor hub assembly. In turn, the wave generator causes the external flex gear teeth to sequentially engage the ring gear internal gear teeth as the wave generator rotates within the flex gear. As the flex gear is mounted to the strap drum, the differential rotation between the flex gear and ring gear causes the strap drum to rotate relative the rotor hub assembly.

Abstract: An erosion resistant ceramic component is synthesized from a silicon oxynitride precursor powder with a sintering aide. The sintering aide, preferably aluminum oxide and/or lutetium oxide are added to the silicon oxynitride precursor powder and ball milled. The composition is then decanted, dried and granulated. The composition is then formed into the shape of the desired component by hot pressing in a graphite die. A heat treatment process may also be applied after hot pressing to further improve erosion resistance by crystallizing amorphous grain boundary phases to provide a ceramic component having sand erosion characteristics superior to electro-formed nickel. The component provides a dielectric constant which is much lower than the dielectric constant of an electro-formed nickel component.

Abstract: A variable diameter rotor blade assembly includes a rotor hub with multiple rotor blades each having an outboard blade section telescopically mounted to an inboard blade section. A reeling assembly includes a strap drum that extends and retracts a strap attached to each of the outboard blade sections to selectively change the diameter of the rotor blade assembly. The strap includes a body portion extending toward the drum and a termination portion attached to each of the outboard blade sections. The termination portion is made from a rigid fiber reinforced composite that has a higher rigidity than the body portion. A transition region is formed between the body portion and the termination portion and is made from a flexible matrix-fiber composite that has a higher rigidity than the body portion and a lower rigidity than the rigid fiber reinforced composite.

Abstract: A flight control system includes a blending algorithm which evaluates the current flight regime and determines the effectiveness of the flight controls to effect the rotational moment of a hybrid vehicle about the roll axis. Gain schedules for both roll cyclic and aileron control provide a quantitative measure of control effectiveness. Based on the respective gain schedules, the algorithm determines how much of the control commands should be sent to each control surface. The result is that for a given control command, the same amount of roll moment will be generated regardless of flight regime. This simplifies the underlying flight control law since the commands it generates are correct regardless of flight regime.

Abstract: A processed fiber is used to distribute energy from an electromagnetic (EM) energy source to a material in which the fiber is embedded. The electromagnetic energy source supplies electromagnetic energy to the fiber and the fibers emit portions of the EM energy along the length of the fiber. The sealant material absorbs a quantity of the electromagnetic energy sufficient to cure the sealant material and propagates excess electromagnetic energy through the sealant material without significant additional absorption. This prevents the sealant material from over-curing. Additionally, a fully cured material can be used to generate thermal energy and thereby serve as a heat blanket that can be used to de-ice aircraft.

Abstract: A drive system for a variable diameter rotor system includes a plurality of rotor blade assemblies with inner and outer blade segments. The outer blade segment being telescopically mounted to the inner blade segment. The VDR retraction/extension system includes a reeling system driven by a harmonic gear system. The reeling system includes a strap drum for winding and unwinding a strap attached to the outer blade segments. In operation, a control shaft drives the wave generator at a higher or lower rotational speed relative to a main rotor drive shaft assembly thereby causing the wave generator to rotate relative to the rotor hub assembly. In turn, the wave generator causes the external flex gear teeth to sequentially engage the ring gear internal gear teeth as the wave generator rotates within the flex gear. As the flex gear is mounted to the strap drum, the differential rotation between the flex gear and ring gear causes the strap drum to rotate relative the rotor hub assembly.

Abstract: An alignment device mounts to a missile system such that the view of a missile seeker is limited to limited fields of view at predetermined positions relative to a known reference such as the missile centerline. Once the alignment device is mounted to the missile system, an energy source emitting energy viewable by the seeker is located within a field of view. Once the seeker has locked-on to the energy source in a limited field of view, the pointing angle of the seeker can be observed by a measurement device communicating with the missile controller. Any pointing angle observed by the measurement device which differs from the known position defined by the alignment device, represents a displacement error of the seeker. Appropriate compensation is then applied to the missile controller such that alignment errors are accounted for.

Abstract: An actuator is disclosed for an active vibration and noise control system in an aircraft. The actuator is configured to attach a vibrating component, such as a gearbox mounting foot, to an aircraft support structure. The actuator is actuated by the control system to control the transmission of vibratory loads from the gearbox foot. The actuator includes a housing and a mounting member. The housing mounts to the aircraft. The mounting member attaches to the vibrating component within the aircraft. A piston arrangement is attached to the housing and includes a sleeve located within the housing, and a piston slidably disposed within the sleeve. A bearing assembly engages the mounting member with the piston. The bearing assembly includes a first bearing located between the mounting member and an inner bearing member. The first bearing is adapted to transmit axial motions between the mounting member and the piston.

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 in combination with 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 first and lower second elongate carriage members mounted in synchronized movable combination with the stanchion, and a row of suction cups mounted in combination with each carriage member.