Abstract: A wind tunnel with a closed section for aeroacoustic measurements with an anechoic coating including: a) a first cavity having a thickness D1 in a range of 20?D1?50 mm filled with a fibrous material with a flow resistance R in a range of 10?R?50 kRayl/m; b) a first microperforated panel having a thickness t1 in a range of 0.25?t1?0.75 mm and with a perforation percentage p1 in a range of 15%?p1?30%; c) a second air cavity having a thickness D2 in a range of 10?D2?30 mm; d) a second microperforated panel having a thickness t2 in a range of 0.25?t2?0.75 mm and with a perforation percentage p2 in a range of 15%?p2?30%. The perforations of the panels can be circular or longitudinal slot-shaped having a diameter d or width w in a range of 0.2?d, w?0.5 mm.

Abstract: A device (1) for the installation of a conducting component (2) on a structure (3) made from composite material, the inside of this structure (3) comprising a substance which can be ignited, which comprises an installation element (4) onto which the conducting component (2) is positioned, a conducting insert element (5), by means of which the installation element (4) is joined to the composite material structure (3) by its internal part, a conducting layer (6) arranged on the external part of the installation element (4) and a conducting fixing element (7) which joins the structure (3) and the installation element (4) to the insert element (5) and the conducting layer (6) so that the device (1) defines a low impedance current path through the conducting layer (6) and the insert element (5) through which the energy is dissipated from an atmospheric discharge to the component (2) or to the structure (3), the interior face of the structure (3) remaining isolated.

Abstract: A re-usable retainer designed to be used in the curing process of co-bonding uncured stringers. The re-usable retainer is made of metal so it is not necessary to manufacture one retainer for each manufactured stringer. The metallic retainer is placed in direct contact with the uncured resin so the cured stringer has a very good surface quality. The re-usable retainer has a special shape that allows a mild transition of the vacuum bag that avoids vacuum bag breakages. The re-usable retainer is easy to install and to remove.

Abstract: Aircraft fuselage section (32) subjected to impacts of external bodies, the aircraft fuselage having a curved shape with at least a vertical symmetry plane (A-A) and a central longitudinal axis and comprising a skin (35) and a plurality of frames (37) arranged perpendicularly to said longitudinal axis (33), the aircraft fuselage section also comprising at least an inner reticular structure (51, 53) mounted on a supporting structure (41, 43) comprising longitudinal beams (39) attached to the skin (35) and interconnected with said frames (37), said inner reticular structure (51, 53) being arranged for creating at least one closed cell (75) with the skin (35) for improving its resistance and its damage tolerance to said impacts. Said inner reticular structure (51, 53) can be formed by panels (61), rods (65, 65?), cables (67, 67?) or belts (69, 69?).

Abstract: A manhole assembly in the lower skin (37) of an aircraft wing made of a composite material for giving access to an installation placed inside said aircraft wing such as a fuel tank, comprising an inner cover (31) and an outer cover (33) joined by first fastener means (35); the lower skin (37) being configured with a rebated edge (45) around the manhole so that the outer cover (33) can be mounted over the lower skin (37) maintaining the aerodynamic continuity in the aircraft wing surface; the inner cover (31) being mounted over the lower skin (37) by its inner surface with a sealing profile (41) between them and being joined to the lower skin (37) by second fastener means (47).

Abstract: A computer-aided method suitable for assisting in the design of an aircraft by providing relevant dimensioning values corresponding to an aircraft component in transonic conditions inside a predefined parameter space by means of a reconstruction of the CFD computations for an initial group of points in the parameter space using a POD reduced-order model, comprising the following steps: a) Decomposing for each flow variable the complete flow field into a smooth field and a shock wave field in each of said computations; b) Obtaining the POD modes associated with the smooth field and the shock wave field considering all said computations; c) Obtaining the POD coefficients using a genetic algorithm (GA) that minimizes a fitness function; d) Calculating said dimensioning values for whatever combination of values of said parameters using the reduced-order model. The invention also refers to a system able to perform the method.

Abstract: A tail-cone of an aircraft includes a skin provided with a movable fairing which, by a swing articulated mechanism, is supported on the skin in order to allow the opening/closing of the movable fairing and gain access to the inside of the tail-cone. The tail-cone includes actuators for operating the swing articulated mechanism in order to permit the automatic opening and closing of the movable fairing to be carried out.

Abstract: A computer-aided method for carrying out the structural design of a part subjected to damages having significant effects on its structural integrity, such as an aircraft fuselage section subjected to a propeller blade release event, is provided. The method includes: obtaining finite element models that include all the relevant information for an optimization analysis for the un-damaged part and for at least one possible damaged part; defining at least one design variable of the part and at least one design constraint and one load case for the un-damaged part and for the damaged part; providing at least one simulation module for analyzing one or more failure modes of the part; iteratively modifying the design variables of the part for the purpose of optimizing a target function by analyzing simultaneously the un-damaged part and the at least one damaged part using the at least one simulation module.

Abstract: A method for laying-up the tapes of a prepeg composite material in the 0° direction of a non-planar composite component on a suitable mold using an ATL machine includes the steps of: a) determining the trajectories of the tapes as modified trajectories of geodesic trajectories complying with the following conditions in their projections in an horizontal plane: that the curvature radius R2 of their curved segments is bigger than a predetermined value Rmin; that the gap G2p between two contiguous tapes is comprised between 0 and a predetermined value Gmax; and b) providing modified trajectories to the ATL machine. The invention also refers to a non-planar composite component such as an skin of an aircraft wing having the tapes in the 0° direction following trajectories complying with conditions described.

Abstract: It is intended for installing and fitting, in conjunction with other iron fittings, a fairing on an aircraft in correspondence with a housing located at the junction of a stabilizer and a fuselage of an aircraft structure. Wherein each iron fitting comprises: a base plate (5) joined integrally to a torsion box (6) of the stabilizer (3); a mobile support (7) joined integrally to the fairing (1) and which is guided, over a linear movement, over the base plate (5); an adjustment screw (8) that is coupled into a threaded opening (15) of the base plate (5), which screw joins this base plate (5) to the mobile support (7), with the rotation of said adjustment screw (8) in combination with a retaining plate (23) dragging the respective mobile support (7) that is integral to the fairing (1).

Abstract: A method for performing a dimensional inspection of a fabricated composite part (9), comprising steps of: a) Providing a number of points (Iij, Oij) to be inspected in its inner and outer surface; b) Obtaining the positional data of said points (Iij, Oij) from the fabricated composite part (9) hold in a position that allows the access to its outer and inner surfaces as a first set of positional data (WIij, WOij); c) Using said first set of positional data (WIij, WOij) and a second set of positional data (TIij, TOij) of the same points (Iij, Oij) obtained from an analytical model defining its theoretical geometry for calculating the deviations between them taking into account the deformations suffered by the fabricated composite part (9) in said position. The invention also refers to a workstation (11) for performing the method.

Abstract: Composite material part (11) with stringer (31) on ramp, manufactured from a stack of fabrics, which comprises at least one zone (13) with two sectors (17, 19) having a greater thickness than that of the surrounding zones and with the stringer (31) situated on an edge (21) of said zone (13) in which: a) each group of fabrics (27, 27? . . . ; 29, 29?, . . . ) of said sectors (17, 19) has the dimensions to form on said edge (21) a ramp with an acceptable gradient 1/p so that the stringer (31) remains situated on the ramp; b) the stacking of the zone (13) is carried out firstly by placing the fabrics (27, 27?, . . . ) of the first sector (17) and on these the fabrics (29, 29?, . . . ) of the second sector (19) in such a way that in the coinciding section (35) of said edge (21) the gradient of the resulting ramp is 1/(p/2).

Abstract: Aircraft fuselage frame (9) in composite material with stabilized web whose omega-shaped cross section (11) in at least a first segment (31) is formed by one head (23), two webs (25, 25?), two feet (27, 27?) with a stiffening element (29) between the two webs (25, 25?). The invention also refers to a manufacturing procedure for the first segment (31) comprising steps to: a) provide an external element (41) with an omega-shaped cross section formed by one head (43), two webs (45, 45?) and two feet (47, 47?), and an internal element (51) with omega-shaped section formed by one head (53), two webs (55, 55?) and two feet (57, 57?), with their respective webs (45, 55; 45?, 45?) and feet (47, 57; 47?, 57?) oriented in parallel; b) join the internal element (51) to the external element (41).

Abstract: Aircraft fuselage frame in composite material with stabilising ribs which, in at least a first sector (31), comprises a frame (9) with an omega-shaped cross-section (11) formed by a top element (23), two webs (25, 25?), two feet (27, 27?) which includes at least one internal rib (41) formed by a top element (43) joined to the top element (23) of the frame (9), a web (45), two flanges (49, 49?) joined to the webs (25, 25?) of the frame (9) and a foot (47) aligned with the feet (27, 27?) of the frame (9). The invention also relates to a manufacturing procedure for the first sector (31) of the frame with stabilised web (10) comprising steps for: a) providing a frame (9) and at least one internal rib (41) with the configurations indicated; b) joining at least said internal rib (41) to the frame (9).

Abstract: A method for repairing the skin of the fuselage of an airplane from the inside to be used when the skin of the fuselage has been damaged between a first stringer and a second stringer adjacent to the first one is provided. The method includes filling the damage, placing a first doubler over the filling, placing a second doubler over the first doubler and bending this second doubler at least over a flange of one of the stringers, and securing the second doubler.

Abstract: A manufacturing procedure of a composite material part (11), with an edge region (13) destined to be joined to another part by rivets, making a change in the geometry of said edge region (13) with respect to an initial surface (41) on the part's external face, comprising the following steps: a) providing a laying-up tool incorporating a modified surface (43) according to said change in the edge region (13) geometry; b) providing the composite material plies needed for the laying-up of the part, with the plies (51, 51?, . . . , 51n) destined for the edge region (13) of the part affected by the geometric modification being already cut so that they finish as they reach said modified surface (43); c) laying-up said plies over said tool and curing the resultant laminate. The invention also refers to a lower skin of an aircraft wing (11) manufactured according to said procedure.

Abstract: The invention comprises a triform fitting 1, essentially made from non-metallic composite materials including several strengthening cross ribs 4 for joining symmetrical flanges 3 and a longitudinal flange 2. The symmetrical flanges 3 include cross slots 8 for receiving the run-out 16 of the webs 11 of several T-shaped internal stringers 9 that form part of the torsion boxes 6. The feet 10 of the stringers 9 are joined along one of their faces to the skins 7 of the torsion boxes 6, while the end zones of the free faces of said feet 10 are placed against the outer face of the symmetrical flanges 3 of the triform fitting 1. This ensures that the symmetrical flanges 3 of the triform fitting 1 remain inside the torsion boxes 6. Alternatively, the fitting 1 may not include the cross slots 8.

Abstract: The invention relates to a structural configuration of the rear fuselage (4) of an aircraft with propeller engines (1) comprising propellers (23) formed in turn by blades (3), the mentioned propeller engines (1) being located at the rear part of the aircraft and the empennage (5) of the aircraft in turn being located behind the plane of the propellers (23), characterized in that the structural configuration of the rear fuselage (4) comprises an outer skin (6) and an inner skin (7), both skins (6, 7) being joined by means of radial elements (13) configuring cells (14), such that the obtained structural configuration maximizes the torsional strength of the rear fuselage (4) of the aircraft in the event of damage of the mentioned rear fuselage (4) due to the detachment of one of the blades (3) of the propeller engines (1).

Abstract: A method of designing an aircraft component formed by a number of elements that includes a phase to estimate the effect of a variation of a design variable on the component weight which method includes the following steps: a) providing the main primary structure basic data of the aircraft component and the Reserve Factors associated to its design criteria; b) obtaining a breakdown of the component weight by such design criteria using a fictitious weight calculated taking into account the relative importance of their critical design criteria; c) obtaining the weight effect of a design variable variation, recalculating firstly the new Reserve Factors using suitable functions for the variation of the Reserve Factors vs. the variation of the design variable and, secondly, recalculating the component weight using suitable functions for the variation of the element dimensions vs. the variation of the Reserve Factors.

Abstract: The invention discloses a method for prevention of porosity in composite material parts (1), which is applied when the curing stage of the part (1) is being carried out on a female tool (2). In the curing stage, an adhesive (4) is placed on at least one of the areas of the radii (5) of the composite material part (1), so that the possible subsequent appearance of porosity in said areas of the composite material part (1) is prevented. Thus, the adhesive (4) acquires the fluidization temperature before the resin of the composite material and it is displaced filling the holes generated during the placement of the part (1) on the female tool (2), in the area of the radii (5) of the part (1), during the coupling between the part (1) and the female tool (2).