Abstract: A method of manufacturing a wing structure includes laying a plurality of layers of preimpregnated material on a first mould half and on a second mold half so as to form a first fresh skin and a second fresh skin of the wing structure. A plurality of layers of preimpregnated material are laid in succession on a shaped apparatus to form a fresh leading edge skin of the wing structure. Fresh spars of preimpregnated material are formed. A wedgelike body of expanded plastics material is formed, this body being designed to be interposed between the first and second skins at the trailing edge of the wing structure. The fresh spars are positioned in a coordinated way on the first fresh skin, removable support members also positioned next to the spars. The second mold half is turned over on to the first mold half so as to position the second fresh skin on the spars and the supports, to produce a fresh wing structure. The fresh wing structure is subjected to a polymerization cycle, using a vacuum bag.

Abstract: A hollow manufactured body has at least one wall of non-ferromagnetic material with an outer surface and an inner surface facing a cavity of the body. Two mutually magnetically attracted sliders are positioned on the inner and outer surfaces. The outer slider is moved manually across the outer surface to a predetermined point where the wall thickness is to be detected; the inner slider on the inner surface follows the movements of the outer slider due to the effect of the magnetic attraction. A transducer on the outer slider is used to measure the force required to move a magnet away from the outer surface of the wall. The value of the thickness of the wall at the predetermined point is then derived from the measured force.

Abstract: A beam of fiber-reinforced curable thermosetting composite material is preliminarily assembled in an uncured condition. The beam is placed between two forming tools, namely a lower and an upper tool, shaped in such a way as to give the lower and upper flanges a predetermined shape, at least one of the flanges having a non-rectilinear profile viewed in a longitudinal vertical plane. Two longitudinally elongate rigid inserts are placed between the flanges at the sides of the web and are covered in respective airtight tubular bags. The spaces between the upper tool and the lower tool on the two opposite longitudinal sides are sealed. The open opposite ends of the tubular bags are also sealed in such a manner that the pressure applied in an autoclave during the step of curing causes the tubular bags to swell and presses them against the two opposite faces of the web and against the flanges of the beam. On completion of curing, the upper forming tool is removed and the inserts are extracted sideways.

Abstract: A method for prognostics of a structure subject to loads, particularly an aircraft structure, includes, detecting the state (strains) of the structure at multiple primary points and additional points. The loads acting on the structure associated with the state detected in the primary points are determined. Based on the determined loads, the state of the structure in the additional points is estimated. The estimated state of the structure is compared with the state detected in the additional points. A soundness state of the structure is assessed if the estimated and detected values of the state quantity are in agreement, or a defectiveness state of the structure if such values differ.

Abstract: A braking system for an aircraft provided with undercarriage, wherein an axial-flux reversible electrical machine is associated to at least one wheel of the undercarriage and is set in rotation by the rotation of the wheel. Current-dissipator is provided, which can be connected to the windings of the axial-flux reversible electrical machine during rotation of the wheel in the landing phase for dissipating in the current-dissipator the induced currents generated by the machine, which behaves as current generator, and producing a braking effect that slows down the movement of the wheel. An epicyclic reducer is provided between the wheel of the undercarriage and the rotor of the reversible electrical machine. The epicyclic reducer provides a transmission ratio T in such a way that the rotor will turn at a velocity T? with respect to the velocity of rotation ? of the wheel.

Abstract: An aircraft chaff dispenser includes an elongated hollow housing intended to be fixed to the structure of the aircraft so as to be oriented in the longitudinal direction of the aircraft. The housing has a pair of side walls and the front of each side wall is provided with a pair of lateral air intakes each having a circular through-hole with a diameter d and a fence located behind the hole in the longitudinal direction, or in the direction of travel, of the aircraft at a distance 1 from the center of the hole and having a shape in the form of a horizontally lying V with its vertex directed away from the hole. The diameter d of the hole is between 8 and 12 mm. The ratio h/1 between the height h of the fence at the vertex of the V and the distance 1 is between 0.8 and 1, while the ratio h/d between the height h and the diameter d is between 1.5 and 2.

Abstract: A process is for preparing a self-healing composite material including a matrix of epoxy polymer in which a catalyst of ring opening metathesis reaction and vessels containing at least one monomer able to polymerize due to a ring opening metathesis reaction are dispersed. The process includes the preliminary step of dispersing at molecular level the catalyst in a mixture containing at least one precursor of the epoxy polymer, and then the steps of dispersing, in the mixture, the vessels and a tertiary amine acting as curing agent of the precursor, and the step of curing the mixture by at least a first heating stage performed at a temperature between 70 and 90° C. for a time between 1 and 5 hours, and a second heating stage performed at a temperature between 90 and 170° C. for a time between 2 and 3 hours.

Abstract: A method of manufacturing a curved structural element made of composite material has a complex, open cross-section the structural element is formed by the assembly of components made of composite material. A plurality of flat, fresh components are prepared, each component being constituted by a flat layer of curved fibres previously infused with resin, combined with a pre-impregnated layer with straight fibres. Hot-forming of the flat, raw components is then performed. The hot-formed, fresh components are then assembled in accordance with a predetermined sequence on a polymerization tool. The tool includes a shaped, inflatable device astride which a C-shaped raw component is deposited. Finally, the fresh components assembled on the tool are subjected to a polymerization cycle in an autoclave. The inflatable device is inflated by the pressure produced in the autoclave to apply a predetermined pressure from the inside of the C-shaped fresh component.

Abstract: For an arcuate structural member (10) of a fuselage frame, tapes of resin pre-impregnated unidirectional fibers are used. The member (10) includes a web (11) lying in a radial plane and a radially outer cylindrical flange (12). An elongate, arcuate forming mandrel (M1) having a flat radial surface (F) forming an angular edge (D) with a radially outer, convex cylindrical surface (S) is used and a series of promontories (P) radiating outwardly with respect to the cylindrical surface (S) are provided. Layers of pre-impregnated composite material are laid on the mandrel (M1) to form a first flat arcuate laminate (20?), with a part (20?) of the laminate projecting radially outwardly beyond the angular edge (D). The mandrel (M1), the laminate (20?) and the promontories (P) are covered with a membrane (E). A vacuum is then applied to urge the projecting part (20?) of the laminate against the cylindrical surface (S) and against the promontories (P).

Abstract: A jet of air is impelled on to the upper surface of a flap in order to increase its lift. Part of the air in this air jet is drawn, through air intakes, from the air stream flowing over an upper surface of the fixed part of the wing, located upstream of the flap. The air jet drawn in by suction by the air intakes is reinforced by a jet of compressed air blown through a passage which opens immediately downstream of the air intakes. This creates a combined jet of the air sucked in and the blown jet, which is ejected on to the upper surface of the flap through outlet apertures located on the rear edge of the fixed part of the wing.

Abstract: The process for monitoring the curing reaction of a polymeric matrix, in which carbon nanotubes are dispersed whereby a composite material is formed, provides for: arranging an electric circuit comprising at least a generator of a substantially constant voltage, an amperemeter and two electrodes immersed into the composite material, whereby the composite material interposed between the electrodes closes the electrical circuit, and tracing the current intensity value measured by the amperemeter, which is correlated to the progress of the curing reaction of the polymeric matrix, so as to control said progress.

Abstract: In order to repair a composite-material panel forming part of the external surface of an aircraft, a portable device is applied onto that surface, the portable device including an inflatable chamber consisting of a flexible and airtight membrane and a concave body of rubber-like material sealed with the membrane. The concave body incorporates an inextensible inner reinforcement. Pressurized air is introduced into the chamber via a valve. A further valve, which passes through the membrane in a zone of the membrane external to the chamber, is used to suck air from one side of the membrane to the other.

Abstract: A wing-flap assembly includes a flap made up of a plurality of flap sections, in which each flap section is connected to the preceding one in a rotatable manner, and one or more actuator devices adapted to control the rotation of the flap sections. Each actuator device includes an extended element made of shape memory alloy and an arch-shaped framework made of elastic material, to which the extended element is fixedly connected under tension. Each end of the extended element is fixed to a respective end of the arch-shaped framework. At least one of the actuator devices is connected at one end to the first of the flap sections, and on the other side it is adapted to be connected to a wing structure.

Abstract: A covering structural element is adapted to close an elongate gap provided on an aerodynamic surface of an aircraft. Such an element has a strip-shaped body made of metal material, including a fixing portion, adapted to be fixed along one of the longitudinal borders of the elongate gap; a sliding portion adapted to urge in a sliding manner on the other of the longitudinal borders of the strip-shaped gap; and a connection portion, connecting the sliding portion to the fixing portion, the thickness of which is so sized as to allow, in use, a controlled elastic bending of the structural covering element. The covering structural element has a profile so sized as to be tapered at the transition from the fixing portion to the connection portion and from the sliding portion to the connection portion, the covering structural element having a smooth surface on the side intended to face away from the elongate gap.

Abstract: A method for estimating an angle of attack and an angle of sideslip of an aircraft having a plurality of control surfaces each adjustable with respect to an associated reference surface. The method includes measuring quantities representative of the angle formed by each control surface with respect to the associated reference surface, and measuring an effective rolling speed, an effective pitching speed, and an effective yawing speed of the aircraft. A linearized model of a state observer is defined according to the following equations: { ? x .

Abstract: An article of composite material includes a plurality of plies of material consolidated through the application of pressure and heating, in which each material ply is made by a resin matrix reinforced with fiber material. The article includes heating electrical resistance and temperature sensing devices embedded in the composite material, which are respectively placed in at least one interface zone between the material plies and are suitable to allow a temperature control of the article in service.

Abstract: In order to manufacture beams of composite material with a J-shaped cross-section, a curing apparatus includes a bar supported parallel to a table by two end supports. A J-shaped beam of uncured composite material is prepared and arranged on the apparatus, positioning the bottom flange of the beam so that it faces the table and resting the web and the upper flange against two respective sides of the bar. The beam is covered with a vacuum bag and pressure and heat are applied inside an autoclave in order to cure the resin in the beam.

Abstract: A method of manufacturing a curved element made of composite material includes: preparing at least one dry, flat reinforcing layer with curved fibers. A resin film is combined with the dry, flat reinforcing layer, and heat and pressure are applied in controlled manner to bring about the infusion of the resin into the reinforcing layer and to obtain at least one layer of pre-infused material. At least one prepreg layer is prepared with straight fibers impregnated with resin compatible with the resin of the pre-infused material. The layer of pre-infused material and the prepreg layer are superimposed on one another to obtain a layered structure. The layered structure, arranged on a shaped support tool is subjected to a polymerization cycle to obtain the curved element.

Abstract: A tool for the infusion of a resin into a preform made of fiber material includes a mould which can be closed around the preform and in the body of which at least one inlet duct is formed to allow resin to be injected into the mould so that the resin can be infused into the preform. At least one reservoir which can contain the resin, is also formed in the body of the mould and is connected to the at least one inlet duct. The mould can be inserted in an autoclave and the reservoir is configured to permit the transfer of the resin from the reservoir to the inlet duct under the effect of the temperature and of the pressure that are produced in the autoclave, thus allowing the resin to be injected into the mould.

Abstract: A method for manufacturing a recycled prepreg material in strip form, is composed of fiber sections embedded in a resin matrix. A charge of flat scraps from a prepreg starting material is supplied, recording the overall area of the scraps. Then the scraps are fragmented by cutting so as to obtain cut fragments of predetermined size. A strip of backing material and a strip of protective material are supplied. The cut fragments are then distributed in a random manner on the strip of backing material, the feeding speed of the strip of backing material being adjusted depending on the recorded area of the input scraps, so that the cut fragments form a substantially homogeneous layer. The strip of protective material is then arranged over the cut fragments distributed on the strip of backing material, and the whole assembly is then compacted so as to form a strip of recycled prepreg material.