Abstract: A plurality of variable diameter rotors with mechanism for varying the diameter of the rotors synchronously, and including mechanism to limit the diameter of the rotors.

Abstract: A torsionally compliant helicopter blade having its aerodynamic center axis positioned selectively forward of its center of gravity and elastic axes throughout a selected portion of the blade span so that, during operation, the blade will experience airloading which will induce two per rev torsional deflection of the blade to thereby improve rotor performance by reducing the total power required to drive the rotor.

Abstract: An aircraft flight control including a linkage system having a walking beam to which control inputs are imparted and from which a control output is taken and having anti-jamming and over-control abatement provisions.

Abstract: A frangible container is pivotally connected to the sweep wire of mine sweeping equipment so as to intercept the mine mooring wire passing therealong and be pivoted thereby so as to connect thereto during the pivot motion and to be severed as the mooring wire continues to pass along the sweep wire, thereby providing a force to sever the frangible container to allow release of its tethered marker for floating to the surface with the buoyant mine when the mooring wire is severed, following the marker releasing operation.

Abstract: A helicopter rotor and transmission mounting and vibration isolation system in which the transmission is supported from the fuselage by a plurality of elastomeric mounts which are selectively positioned and focused to establish a system roll axis and a system pitch axis on opposite sides of the elastomeric mounts and which mount members are of selected stiffness to establish selected roll stiffness and selected pitch stiffness of the system, to establish the natural frequencies of the system sufficiently below the blade passage frequency to minimize the response of the fuselage to forces and moments imparted by the helicopter rotor and to provide selected torque restraint and lift restraint for the system.

Abstract: A helicopter rotor lead-lag hydraulic fluid damper has an internal anti-torque shaft preventing rotary motion of the dynamic fluid retaining seal. An independent fluid reservoir under centrifugal force supplies lubrication to the low pressure side of the seal. At rest, the fluid returns to the lower reservoir chamber by gravity.

Abstract: An aircraft door adapted to pivot about a pair of vertical hinges is detachably fixed to the door frame by a secondary joint at each hinge. Retraction of a short horizontal pin at each secondary joint releases the door for jettison.

Abstract: An interblade seal and vibration damper to be positioned in the damper cavity defined between a rotor disc, adjacent blades and adjacent blade platforms so as to seal across an interplatform gap by providing line contact between the damper and the platforms on opposite sides thereof for the full axial dimension of the cavity and with the damper shaped so as to have a low center of gravity for operational stability and which damper also responds to centrifugal force during rotor operation to establish damping friction between said damper and said platforms when the platforms move circumferentially.

Abstract: A helicopter rotor having flexible blades mounted to a drive shaft by means of hub arms, wherein opposing blade members are interconnected by a common spar passing across the rotor axis. The spar members are supported from the hub arms by spherical bearing members. The universal freedom of these bearing members provides torsional freedom for blade pitching motions without restricting blade flapping or in-plane bending.

Abstract: Apparatus and method for testing elastomeric bearings used for mounting articulated rotor blades on the main rotor head of a helicopter wherein the blade is held stationary and the rotor hub is moved to subject the bearing to simulated flight loads and motions simultaneously, including centrifugal loading and blade flapping, lead-lag, and pitch change motions.

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.

Abstract: A cylinder-and-piston type hydraulic damper has spaced dual seals on its piston rods to provide annular cavities between seals. A fluid leakage line connects said cavities to the closed reservoir of a fluid leakage indicator which consists of a cylinder closed by a spring biased diaphragm which carries the indicating member of the indicator. The damper chambers on opposite sides of the piston are alternately supplied with fluid from the reservoir during operation of the damper by means of a shuttle valve, thus providing a closed and sealed fluid system including redundant seals with means for indicating that the damper needs servicing upon a predetermined loss of fluid from the reservoir.

Abstract: A wind turbine having a flexible central beam member supporting aerodynamic blades at opposite ends thereof and fabricated of uni-directional high tensile strength material bonded together into beam form so that the beam is lightweight, and has high tensile strength to carry the blade centrifugal loads, low shear modulus to permit torsional twisting thereof for turbine speed control purposes, and adequate bending stiffness to permit out-of-plane deflection thereof for turbine yard control purposes. A selectively off-set weighted pendulum member is pivotally connected to the turbine and connected to the beam or blade so as to cause torsional twisting thereof in response to centrifugal loading of the pendulum member for turbine speed control purposes.

Abstract: A helicopter has a plurality of bifilar absorbers mounted on arms radially extended from the hub of the rotor. A bifilar mass of the required weight mounted at the end of an arm of required length to absorb input excitations at a pendulum amplitude of approximately 30.degree. at design forward speed is mounted on an arm twice the length without a reduction in weight of the bifilar mass to limit pendulum amplitude to 15.degree. while maintaining the original force output. Bifilar motion in the linear range with associated elimination of overtuning produces improved bifilar operation at all flight speeds and eliminates second order vibration due to dissimilar motions resulting from overtuning.

Abstract: A gas turbine consisting of alternate stators and rotors so fabricated that all stator vanes, all rotor blades and all blade tip seals may be removed through the engine case without requiring disassembly or translation of major portions of the gas turbine engine.

Abstract: A low emission combustion chamber in which vitiated products of combustion from a pilot burner are caused to swirl about the combustion chamber axis before fuel droplets are introduced into the vitiated, swirling combustion products for flash vaporization therein to produce a vaporized, swirling, vitiated fuel-air mixture so as to effect ignition lag until swirling combustion air can be mixed with the swirling mixture to molecularly premix the fuel and air and increase its oxygen content to reduce the ignition lag to effect autoignition at an equivalence ratio less than 1 so as to effect high-rate, lean burning in the primary combustion chamber.

Abstract: A helicopter has a plurality of bifilar absorbers mounted on arms radially extended from the hub of the rotor. A bifilar mass of the required weight mounted at the end of an arm of required length to absorb input excitations at a pendulum amplitude of approximately 30.degree. at design forward speed is mounted on an arm twice the length without a reduction in weight of the bifilar mass to limit pendulum amplitude to 15.degree. while maintaining the original force output. Bifilar motion in the linear range with associated elimination of overturning produces improved bifilar operation at all flight speeds and eliminates second order vibration due to dissimilar motions resulting from overtuning.

Abstract: A variable ratio bypass turbojet engine comprising a front fan core engine and a forward fan connected thereto by an inverter valve arrangement which comprises a fixed forward duct system and a fixed after duct system selectively shaped and joined by flapper valve mechanism. The flapper valve mechanism may be actuated so that the bypass ratio of the engine can be varied to produce a low bypass ratio engine during cruise operation mode wherein the front fan air is conducted to the core engine fan and the auxiliary inlet air is discharged overboard, or to a high bypass ratio engine for take-off condition mode wherein the front fan air is discharged to atmosphere through a thrust nozzle and the auxiliary inlet air is directed to the core engine fan.

Abstract: A helicopter cross beam rotor is shown including upper and low coaxial composite blade spars at right angles secured by tension bolts which pass through the composite spars and are held by threaded nuts to a rotor hub at the upper end of a rotor drive shaft. A metal cap plate above the upper spar and a spar-to-spar filler piece are also provided. Torque between the spars and the rotor hub is reacted by intermeshing ribs and grooves on the confronting faces of the hub, the filler piece and the cap plate. The bolt holes in the composite spars are oversize so that the bolts do not react torque between the rotor hub and the composite spars.

Abstract: A low emission combustion chamber in which vitiated products of combustion from a pilot burner are caused to swirl about the combustion chamber axis before fuel droplets are introduced into the vitiated, swirling combustion products for flash vaporization therein to produce a vaporized, swirling, vitiated fuel-air mixture so as to effect ignition lag until swirling combustion air can be mixed with the swirling mixture to molecularly premix the fuel and air and increase its oxygen content to reduce the ignition lag to effect autoignition at an equivalence ratio less than 1 so as to effect high-rate, lean burning in the primary combustion chamber.