Abstract: An aircraft comprising a pair of ducted thrusters. Each of the ducted thrusters comprises a duct surrounding a rotor assembly with a rotor hub having a plurality of rotor blades extending therefrom, wherein the plurality of rotor blades have a modulated angular distribution about a central longitudinal axis of the duct. Each of the ducted thrusters further comprises a stator assembly having a stator hub with a plurality of stator vanes extending from the stator hub to an interior surface of the duct, wherein each of the plurality of the stator vanes are angularly modulated around the stator hub such that angular spacing between pairs of adjacent vanes of the plurality of stator vanes varies for each pair of the adjacent vanes.

Abstract: A reduction gearbox for an aircraft engine, including an input pinion configured to be driven by the aircraft engine, a input gear meshed with the input pinion, a drive gear meshed with the input gear, an output pinion, and an output gear meshed with the output pinion and configured to drive an output shaft of the aircraft engine. The reduction gearbox is selectively configurable between an engaged configuration where the input gear and output pinion are drivingly engaged and a disengaged configuration where the input gear is rotatable independently of the output pinion. The output shaft may drive a propeller and the gearbox may include a propeller brake. A method of driving a generator of a turboprop engine is also discussed.

Abstract: A turboprop propulsion unit includes at least one pusher propeller 5, 6 driven by an aircraft gas-turbine engine, with the aircraft gas-turbine engine being arranged in front of the pusher propeller 5, 6 in a direction of flight. A turbine outlet area 9 is arranged at the front in the direction of flight and a compressor area 14 faces towards the pusher propeller 5, 6.

Abstract: One embodiment of a Vertical Take-off and Landing (VToL) air-vehicle (FIG. 1.) having a horizontal rotor, a. providing lift and propulsion, and communicating at or near its centre to structural elements, or fuselage, b. Upon or within the fuselage structure is attached a platform, to which a payload, or occupant or pilot, d. is secured in such a manner as to permit a movement, or range-of-motion, of the payload, as a means of weight-shifting, or mass-balancing, of the vehicle for stability and control in flight. At least two planar elements, or descent-vanes, c.i & c.ii are connected to a structural element of the fuselage at a location which provides vertical and horizontal separation between the rotor and the descent-vanes, thus creating a tandem, biplane arrangement of two aerodynamically active elements which are aerodynamically balanced to provide stability and controllability in hovering flight, in forward flight, and in un-powered gliding and vertical descents.

Abstract: An aircraft propeller-engine layout includes at least one engine (10) arranged in a tail (2) of a fuselage (1) of an aircraft and has at least one propeller arrangement, with a shaft of the propeller (6, 7) being connected to a shaft (21) of the engine (10) via at least one transfer shaft (12).

Abstract: A propeller for an aircraft is disclosed. The propeller has an odd number of unequally circumferentially spaced blades. The propeller may be provided as part of a contra-rotating propeller arrangement and/or aft of a pylon on an aircraft. The propeller has been found to reduce noise levels and to be efficient.

Abstract: The aircraft includes at least one engine having counter-rotating rotors, the engine or at least one of the engines having imbalances associated with at least one ellipse. The aircraft includes a means capable of controlling the engine or at least one of the engines such that, at a given engine speed, the large axis of the ellipse or at least one of the ellipses extends in a direction for which the vibrations generated by the engine or engines have a minimum intensity in at least one predetermined site, particularly in a predetermined area, of the aircraft.

Abstract: An aerodynamic lifting-thrusting propulsion device has a frame with an axis, relative to which the frame is arranged with a possibility of rotation, a cardan joint having a cross, at least two aerodynamic surfaces, each of which is mounted on the cardan joint with a possibility of oscillations synchronously with a rotation of the frame, a rod mounted on the frame, the cardan joint being connected with the rod, the cross of the cardan joint having axes which are mutually perpendicular and located correspondingly in mutually perpendicular planes intersecting along an axis of the rod, one of the axes of the cross extending through an axis of rotation and an axis of the rod, the rod being arranged parallel to an axis of the frame, the axis of the frame being connected with each of the aerodynamic surfaces by a mechanical transmission providing a rotation of the aerodynamic surface synchronously and opposite to a rotation of the frame.

Abstract: In a contra rotating propeller engine propeller blade assemblies are provided which rotate in opposite directions as a result of association with an epicyclic gear assembly acting as a differential gearbox. A carrier is provided to drive one propeller blade assembly. Actuators are provided to cause pitch angle adjustment of the respective propeller blades of the assemblies. These actuators, are secured upon a stationary structure and act through actuator rods and appropriate mechanisms to cause such angular pitch adjustment. Rotational de-couplers are provided to rotationally isolate the actuators whilst an actuator rod part acts across the assemblies and a rotational de-coupler to de-couple contra rotation between the assemblies whilst still allowing axial displacement for adjustment of the other propeller blade assembly.

Abstract: A power and communications connection arrangement for a miniature, unmanned aircraft having data handling capability. The aircraft has a microprocessor for managing flight control, a GPS receiver, a communications radio frequency transceiver, and data handling apparatus. The latter may be any of a sensor for gathering environmental data, sensing aircraft altitude or attitude, a data relay station, or any combination of these. The data handling apparatus is part of a removable module mounted to and detachable from the aircraft. The connection arrangement includes stationary power and communications terminals fixed to the module, and corresponding free power and data cables completing respective power circuits and communications links within the aircraft. In the preferred embodiment, the microprocessor, at least one sensor, and a battery pack are located in the module, and a radio transceiver, a GPS receiver, controls such as rudder and elevator, and other sensors are located in the airframe.

Abstract: A propeller for fluid propulsion comprises a pair of substantially rigid blades which rotate about their longest dimension in opposite directions, the blades each being oppositely helically twisted along the longest blade dimension and positioned together in synchronously opposite, rotatable condition, with the rotating blades passing by each other in closely spaced relation substantially without physical contact. The blades occupy a tubular housing enclosing the rotating blades in closely-spaced relation between the housing and blades. Further sealing is provided by each blade side carrying a hemicylindrical wall with a concave side facing outwardly, each hemicylindrical wall being helically twisted in a manner identical to the helical twist of the blade. The hemicylindrical walls have a cross-sectional diameter that permits, upon blade rotation, an edge of the other blade to sweep across the concave side of each hemicylindrical wall in closely spaced relation for sealing purposes.

Abstract: A propeller for fluid propulsion (such as air or water) comprises a pair of substantially rigid blades. The blades are mounted for rotation about respective, separate, parallel rotation axes, with the axes being also substantially parallel to the longest dimension of the blades. The blades each define a plate that is oppositely helically twisted along the longest blade dimension compared with the other blade. The blades are positioned together in synchronously opposite, rotatable condition, with the rotating blades passing by each other in closely spaced relation without physical contact. A tubular housing encloses the rotating blades in closely-spaced relation between the housing and blades. Such a blade system can provide a high velocity jet of large mass at relatively low rotational speed.

Abstract: An airboat propelling system is provided wherein a propeller is rotated by a hollow driven shaft. A further embodiment is provided wherein two propellers are rotated in opposite directions by counter-rotating coaxial hollow driven shafts. Floating stiffener bearings positioned between the coaxial hollow driven shafts suppress flexion and protect the opposing surfaces of the shafts. These innovative techniques permit a minimization of size and weight, as well as a reduction in rotational speed of the propellers, maximizing efficiency and decreasing noise.

Abstract: An aircraft of disc-shaped configuration provides the capability of vertical take-off and landing; straight horizontal flight; and three-dimensional maneuverability in the air by means of a plurality of counter-rotating lifting rotors assembled of fixed pitch or of self-adjusting pitch aerofoil blade elements; and, submersibility of the aircraft in water is achieved by means of a marine propulsion module using two counter-rotating hydrofoil rotors for up or down thrust, and a tunneled conventional marine propeller for horizontal travel. The marine propulsion module is detachable for emergency and for use with the main frame aircraft of a variety of other detachable modules for different tasks and missions. Exceptionally adaptable for any existing power plant, including nuclear, it is best suited for the environment-friendly types, like integrated steam motor on hydrogen and oxygen burning.

Abstract: Several innovative systems for an aircraft, and aircraft incorporating them, are disclosed. Features include inboard-mounted engine(s) with a belt drive system for turning wing-situated propellers; compound landing gear integrating ski, pontoon and wheel subcomponents; pivotal mounting armatures for landing gear and/or propellers which provide a plurality of possible landing gear and/or propeller configurations; and a compound wing structure featuring extendable wing panels that permit the wing span of the aircraft to be nearly doubled while in flight. Aircraft incorporating such features will enjoy several safety advantages over conventional multi-engine aircraft and will be capable of modifications during flight which permit landings on any of snow, hard surfaces (runways) and water.

Abstract: A tiltwing aircraft, capable of in-flight conversion between a hover and forward cruise mode, employs a counter-rotating proprotor arrangement which permits a significantly increased cruise efficiency without sacrificing either the size of the conversion envelope or the wing efficiency. A benefit in hover is also provided because of the lower effective disk loading for the counter-rotating proprotor, as opposed to a single rotation proprotor of the same diameter. At least one proprotor is provided on each wing section, preferably mounted on the wingtip, with each proprotor having two counter-rotating blade rows. Each blade row has a plurality of blades which are relatively stiff-in-plane and are mounted such that cyclic pitch adjustments may be made for hover control during flight.

Abstract: A method of creating thrust reversal for an engine having counter-rotating forward and rear propeller blades. The forward blades are set at a positive angle of attack to produce an orderly flow of air toward the rear blades. The rear blades are set at a negative angle of attack to produce reverse thrust. The net effect is that the thrust produced by the rear blades overbalances that of the forward blades to produce net thrust reversal.

Abstract: An unducted turbofan engine comprises first and second fan blades journaled for rotation from a folded position substantially parallel to the axis of rotation of the engine to a radially orientated propulsion condition. A releasable shroud normally retains the fan blades in the folded condition and releases the fan blades in a controlled sequence.

Abstract: Load lines connect chordwise spaced portions of a ram air inflated, airfoil canopy to spaced anchors connected to a pilot supporting vehicle frame on which a forward thrust producing unit is removably mounted. The geometry of the assembled aircraft enhances take-off inflation of the canopy, establishes a stable flight frame when airborne, and enables simple engine throttle control of the thrust producing unit to regulate climb, descent and level flight. Common control is applied for both ground steering of the vehicle frame and air-borne steering of the canopy.

Abstract: In one form of the invention, a counterrotating pair of aircraft propellers produces noise in the form of a frequency-modulated carrier wave. The frequency modulation allows a designer to manipulate the energy spectrum of the noise in order to, for example, place much of the acoustic energy into inaudible frequency ranges.

Abstract: The disclosure describes a device for carrying and lifting loads and moving ame by aerodynamic lifting, rotary-wing aerial propulsion, having two coaxial rotors of same diameters rotating at the same speed and in reversed direction through a double crown wheel system which is driven by oppositely disposed rollers. The device includes a crown wheel operatively connected to two rotors which are driven by two rollers, one of which being driven by one or two motors mounted on the body. The internal crown wheel has a hub enabling external blades to be mounted in superimposed relationship.

Abstract: The invention relates to intakes for turbopropeller gas turbine engines of the tractor type. A tractor turbopropeller gas turbine engine comprises a gas generator, an upstream propeller and a downstream propeller. The propellers are positioned upstream of the gas generator, and the propellers are driven via shaft means and gear means. An intake means supplies air to the gas generator, the intake means comprises an intake opening and an intake duct. The intake opening is positioned axially between the propellers, and a portion of the intake duct extends axially through the downstream propeller. This arrangement reduces the length of the shaft and the turbopropeller gas turbine engine, and reduces the weight accordingly. The intake opening is arranged to provide improved protection against ingestion of large foreign objects, such as birds, into the intake duct and gas generator.

Abstract: A device for mounting an aircraft engine and a propeller on a longitudinal member or fuselage of a lightweight aircraft. A sleeve is disposed about the longitudinal member and securing devices which prevent longitudinal movement of the sleeve relative to the longitudinal member are positioned at either end of the sleeve. Vibration dampening rings are disposed between the securing devices and cups which can be threaded along the sleeve placing the rings in the desired compression. The engine and the propeller are mounted on the sleeve. A driving sleeve is rotatably mounted on the sleeve and is drivingly attached at one end to the output of the engine and is mounted at the other end to the propeller. The propeller is rotatable about the longitudinal axis of the longitudinal member and the wing structure and tail structure can be mounted on the longitudinal member as well with the propeller positioned between them. The mounting device can also be used for biplanes.

Abstract: An aircraft drive system having two propellers, each of which is driven independently by a drive belt which is connected to a separate engine. The engines are mounted in cantilever fashion in a spaced relationship on a hollow sleeve. The sleeve is attached by a pair of spaced brackets to the frame of the aircraft. A shaft is rotatably telescopically mounted within the sleeve by bearings located on the ends of the sleeve. A pulley is fixedly mounted on one end of the shaft and is driven by one of the engines for rotating one of the propellers which is fixed on the other end of the shaft. Another pulley is rotatably mounted by bearings on the sleeve and is driven by a drive belt connected to the second engine. The second propeller is telescopically located about the sleeve adjacent the first propeller and is firmly connected to the second pulley which rotates said second propeller completely independent of the first propeller and in an opposite direction than the first propeller.

Abstract: The use of thrusters at the bow and stern of an airship for control of the direction, attitude, and orientation of such an airship is described. The thruster utilizes an electric motor or a gas turbine for power. In the electric motor embodiment, the motor utilizes two contra-rotating rotors which each drive a separate and contra-rotating propeller to generate the controlling jet of air. Thrusters are arranged in pairs at the top, bottom, and each side of the bow and stern of the airship. Lifting thrusters directed downwardly and located above the longitudinal extent of the hull are provided to augment the static lift capability of the airship when under heavy load.