Abstract: In a helicopter tail rotor of flexrotor or, composite bearingless rotor design, a control wheel member is positioned in spaced relationship to the torque tube at the blade inner end and is connected thereto by pivotal push-pull rods connected at one of their ends to the control wheel member and at their opposite ends to the leading edge and trailing edge of the torque tube so that, as the control wheel member is selectively caused to rotate relative to the blade, one push-pull rod pulls upon the torque tube while the other push-pull rod pushes upon the torque tube to cause the torque tube to rotate, and hence the flexible spar to which it is attached to twist to thereby selectively change the blade pitch angle.

Abstract: A helicopter blade of moderate twist having an improved tip utilizing a combination of sweep, taper and anhedral to improve hover performance by unloading the blade tip and reducing the strength of the tip vortex and displacing that tip vortex away from the following blade surface.

Abstract: A helicopter blade of high twist having an improved tip utilizing a combination of sweep, taper and anhedral to improve hover performance by unloading the blade tip and reducing the strength of the tip vortex and displacing that tip vortex away from the following blade surface.

Abstract: A crashworthy aircraft fuel storage system normally operative so that the fuel tank, fuel shut-off valve assembly and the fuel inlet connection to the fuel tank are normally assembled to be free floating with respect to the aircraft structure, and further operative so that crash load conditions will cause the fuel tank to move with respect to the aircraft structure to thereby cause fuel inlet fitting to move therewith and into contact with the aircraft structure so as to impose a momentum force on the fuel shut-off valve assembly to cause fracture thereof and separation of the fuel tank from the fuel inlet fitting, with both parts so separated, sealed to prevent fuel flow therethrough.

Abstract: A hingeless helicopter rotor including an aerodynamically shaped hub having a flexible diaphragm as its bottom wall, which diaphragm is connected to the rotor drive shaft and is elastically deformable in response to blade loading to tilt in any direction with respect to the axis of rotation, and further having at least three equally spaced helicopter blades projecting from and supported from within the hub for rotation therewith and for flexing with respect thereto in response to blade loading so that the flexible hub and the blades coact to produce a low equivalent offset rotor and minimized Coriolis effect.

Abstract: An engine air particle separator for use with a turbine engine and providing a first engine air flow path to the engine inlet in which foreign particles are separated from the air entering engine, and a second direct flow path for air to the engine inlet presenting minimum pressure drop and such that the ram air flows directly into the engine inlet. The second flow path includes actuatable blow-in doors which are actuated by a pneumatic door actuator mechanism operable to cause the doors to close upon the admission of air at operating pressure to the mechanism. Mechanism is provided to prevent the doors from opening when actuating air pressure is applied to the door actuator mechanism but falls below a preselected limit and to permit the doors to open in response to spring bias and ram pressure acting thereagainst when the air at actuating pressure is withdrawn.

Abstract: A ballistic tolerant control actuator of the hydraulic cylinder-piston type and having a hybrid housing comprising a structural outer wall of selected characteristics and wall thickness "t", a central sleeve snuggly fitted within the outer wall and being of selected characteristics and selected wall thickness so that when the outer wall is impacted and/or penetrated by a projectile of diameter D, impact induced stress waves from the outer wall pass into the central sleeve with sufficient intensity to locally disintegrate and clear the central sleeve in the vicinity of the projectile impact, and so that the petals formed in the outer wall will not project farther radially inwardly than the petals which would be formed in the most critical case by a projectile whose diameter D produced the ratio t/D=1/3.

Abstract: A helicopter rotor having an even number of articulated blades wherein opposing blades are interconnected by a common spar passing across the rotor axis. Pitch change is introduced to the blade at the spar-blade attachment joint through a torque member connected at its outboard end to the blade joint and including a control horn at its inner end to receive pitch inputs. Drive for the rotor and support for each blade is provided by a spherical bearing directly connecting the torque member to the blade associated hub arm.

Abstract: In a helicopter rotor, a blade control linkage is externally supported on the rotor hub and connected to the root end of a torque tube to provide torsion inputs to the blade by twisting the flexible spar member, which is enveloped by the torque tube and joined to the torque tube at a predetermined blade radial location. The linkage forms a parallelogram with the torque tube, and short vertical ball joint mounted links incline in two directions to accommodate blade lead/lag and flapping motions without introducing pitch coupling.

Abstract: In a fully articulated helicopter rotor head, utilizing an elastomeric bearing to support each rotor blade and react centrifugal flight loads, a blade restraint, effective in three axes is provided for use during blade folding for aircraft stowage purposes. The restraint allows the blade to be folded through a predetermined fold plane, and held there while preventing or minimizing deflection of the elastomeric bearing.

Abstract: A fluid flow regulator valve to regulate flow to a fluid driven prime mover wherein a selectively shaped, spring biased spool is positioned within a cylinder and has a sensor orifice therein to establish a pressure drop thereacross in response to controlled fluid flow rate and hence cause the spool to move within the cylinder to control both the metering orifice to and the return orifice from the flow conduit which connects the cylinder to the prime mover.

Abstract: A cambered helicopter blade having a swept and tapered tip, and having linear twist throughout the outer 70 percent of the blade span and nonlinear twist inboard thereof.

Abstract: A helicopter stabilator having naturally high response to the main rotor wake excitation frequency in roll and yaw stabilator vibratory modes is selectively mounted so as to be detuned therefrom in antisymmetric stabilator vibratory modes without adversely affecting symmetric stabilator vibratory modes, stabilator vertical stiffness, or stabilator pitch stiffness.

Abstract: A helicopter has main rotor blades foldable over its tail cone and a tail rotor pylon which is foldable about a tail cone vertical hinge from its fore-and-aft flight position through an angle approaching 180.degree. to lie alongside the tail cone. Tail rotor pitch control mechanism includes a cable which extends across the foldable hinged members, direction change pulleys for the cable and an improved 4-bar linkage system which controls the movement of the pulleys within a small envelope circle and maintains a constant tension on the cable throughout the full fold cycle.

Abstract: A cross-beam helicopter rotor in which the torque tube enveloping the flexible spar is supported in relation thereto by an elastomeric primary snubber which is readily replaceable in the field and which utilizes a snubber retainer plate bonded to the spar with an elastomer layer of selected shape factor so that the retainer plate remains adhered to the spar while accommodating all blade and spar pitch and flapping motions and so that the retainer plate elastomer layer is substantially more durable than the elastomer layers of the primary snubber. This primary snubber may be used in combination with an auxiliary snubber.

Abstract: Apparatus to center and compressively load a spherical elastomeric bearing about its static apex during helicopter rotor static mode, which centering means is adjustable from a station external of the rotor and is operable to be out of contact during helicopter rotor dynamic mode.

Abstract: A releasable push-pull sheathed cable control system in which the sheathed cable extends between the control input and the control output and includes a looped portion fixed at one end and releasably fixed at its other end so that tension or compression loading of the cable following cable jamming anywhere within the sheath or therebeyond in a control system will cause deformation or the looped portion and release of one end of the sheathed cable.

Abstract: A helicopter rotor having one or more blades mounted for rotation with the rotor hub and each supported therefrom by an elastomeric bearing, and having a lead-lag damper connected to the blade and the hub and extending substantially parallel to the blade axis, and including the improvement of apparatus for preventing tension loading of the elastomeric bearing as the blade moves radially inwardly as a result of rotor braking.

Abstract: A tuned spring-mass vibration absorber in which a dynamic mass is suspended from a vibrating support member, such as a helicopter fuselage, by a plurality of cantilevered leaf springs integrally connected to the dynamic mass at selected stations so that the mass CG and the spring center of force are coincident, so that the springs are shaped to constitute a substantial part of the vibration absorber effective mass, and so that the springs are pivotally connected to the support member so as to impart no moments thereto.

Abstract: A helicopter rotor having opposed blades interconnected by a common flexible spar which passes across the rotor axis is connected to the drive shaft by clamped hub plates. A spanwise extending torque tube having a pitch horn at its inner end forms a rigid connection with the spar and blade at its outboard end. A centering bearing assembly is positioned at the inner end of the torque tube and spar to react control loads, centralize the torque tube about the spar, and provide pitch, flap, and lead-lag decoupling.