Method for applying a covering to an aircraft wing and aircraft wing obtained by said method

Abstract

A method for applying a covering (1) to an aircraft wing (2) comprising placing a skin (3) provided with one or more inspection ports (4) on the aircraft wing (2); placing a gasket (5) for each of the inspection ports (4) of the skin (3); placing a plug (6) in each of the inspection ports (4); and curing the aircraft wing (2) with the covering (1), the covering (1) comprising the skin (3), the gasket(s) (5), and the plug(s) (6). The aircraft wing (2) comprises a covering (1) applied by said method, which includes a skin (3), one or more gaskets (5), and one or more plugs (6). It reduces application time, recurring costs, and has a positive environmental impact.

Description

[0001] The present invention relates to a method for applying a cover to an aircraft wing, which reduces the application time, the recurrent costs and has a positive environmental footprint impact.Background of the invention

[0002] The wings of aircrafts comprise manhole areas which are covered by gaskets.

[0003] Manhole areas are intended to get maintenance accessibility. For fuel wing tank manholes, the closure is one of the main requirements to be met. This closure is obtained with a gasket, but this needs a supplement to fit properly to the wing on its inner face.

[0004] For example, the gasket is chemically glued to the wing, and each gasket has a different wing interface geometry depending on the manhole and the inner mould line designed surface.

[0005] Additionally, due to tight thickness tolerances and manufacturing variability, dedicated gasket geometries are required per each manufactured part.

[0006] The current method for applying the cover at the manhole area of an aircraft wing is as follows: a wing cover skin is laid-up and cured; gaskets are manufactured by a winding process with glass fiber material and they are cured in an autoclave; the cover skin thickness is measured in the specific areas in which gaskets are going to be installed; each gasket is milled according to the previous cover skin measurements; each specific gasket is pre-installed in dry conditions in the specific wing and measured together to check to be in tolerance; the gaskets are installed manually on the cover skin; the quality thickness is measured; if the measurements are out of tolerance range, a repair must be performed, the gasket must be removed, the area must be cleaned, the gasket must be reworked, e.g., sanded, for achieving the adequate thickness and reinstalled.

[0007] Therefore, this prior art method is time consuming because the gaskets are installed manually one by one.

[0008] EP1614942B1 discloses a seal for sealing component openings in components of a means of transport, in particular for sealing openings in aircraft airfoils and tail units, comprising an inner cover connected to an outer cover via connecting members. An insert may be arranged in the component opening, the outer cover being at least locally adjacent to an insert outer surface, and the inner cover being at least locally adjacent to an insert inner surface.

[0009] US2009294591A1 discloses a cover for the access opening in a composite material aircraft structure comprising an outer cover arranged on the outer part of the aircraft skin, the carbon fiber layers forming the skin being deformed towards the inner part of the aircraft structure, leaving enough space between the aircraft structure and the outer part of the skin for the seating of the outer cover, a composite material plate arranged in the outer part of the skin and surrounding the area for installing the outer cover, and an inner cover arranged on the inner part of the aircraft skin.

[0010] US2012091269A1 discloses a lightning strike protection system for fuel tank access covers in composite structures having a skin, this system comprising an outer cover made of metallic material, that coats externally the fuel tank access covers and an inner cover made of composite material, the outer cover also comprising a lip element, made of the same metallic material than that of the outer cover and being integrated in its structure, and a conductive visco-elastic material or spring element provided over the mentioned lip element.

[0011] US9926085B2 discloses a method for optimising the design of sealing rings of internal manhole covers which close the manhole openings over the inner surface of the skin of an aircraft structure, the surface that is in contact with the inner surface of the skin being the optimized surface of said sealing rings.Disclosure of the invention

[0012] Therefore, an objective of the present invention is to provide a method for applying a cover to an aircraft wing, which reduces the application time, the recurrent costs and has a positive environmental footprint impact.

[0013] The method for applying a cover to an aircraft wing according to the present invention is defined in the corresponding independent claim, and optional additional features are included in the dependent claims.

[0014] In particular, the method for applying a cover to an aircraft wing comprises the following steps: placing a skin provided with one or more manholes on the aircraft wing; placing a gasket for the or each manhole of the skin; placing a plug in the or each manhole; and curing the aircraft wing with the cover, the cover comprising the skin, the gasket or gaskets and the plug or plugs.

[0015] Preferably, the curing is made in an autoclave.

[0016] According to a preferred embodiment, the, or each, gasket, preferably with a continuous thickness, is made from a thermoplastic material, e.g., from recycled polyamide, by injection, and can comprise carbon fiber.

[0017] Furthermore, the thickness of the, or each, plug is preferably adapted according to the thickness of the cover.

[0018] Furthermore, the method according to the present invention provides the following advantages, among others: A high integrated manhole area, including the gaskets and the wing cover solves the high variability and customization needed in the manufacturing method to meet the tight thickness requirements.

[0019] It also solves a high number of repairs due to thickness measurements out of tolerance. Additionally, the method according to the present invention avoids the use of sealants needed to bond the gasket to the wing.

[0020] Furthermore, the method according to the present invention reduces the workload and the manufacturing lead time.

[0021] The following steps of the conventional methods are intended to be reduced, improved, or eliminated: Dedicated gaskets manufacturing method, i.e., winding method, would be superseded, e.g., by thermoplastic injection; Closed lifecycle material used for gaskets injection; Elimination of dedicated measurements and steps, such as milling, pre-installation, bonding, and thickness measurement. Brief description of the drawings

[0022] For better understanding of what has been disclosed, some drawings in which, schematically and only by way of a non-limiting example, a practical case of embodiment is shown.

[0023] Figure 1 is a sectional view of a portion of an aircraft wing with a cover applied, on which the method according to the present invention is applied.Description of a preferred embodiment

[0024] As shown in Figure 1, a cover 1 that is applied to an aircraft wing 2 comprises a skin 3 provided with one or manholes 4, a gasket 5 for each manhole 4 and a plug 6 for each manhole 4.

[0025] The, or each, gasket 5 is preferably made from a thermoplastic material, e.g., from recycled polyamide, by injection, and has a continuous thickness.

[0026] Furthermore, the thickness of the, or each, plug 6 is preferably adapted according to the thickness of the cover 1, providing therefore a thickness control.

[0027] The method for applying the cover 1 to the aircraft wing 2 comprises the following steps.

[0028] Firstly, the skin 3 provided with one or more manholes 4 is placed on the aircraft wing 2.

[0029] Then, a gasket 5 is placed for the, or each, manhole 4 of the skin 3, i.e., the gasket 5 is placed around each manhole 4, and a plug 6 is placed in the, or each, manhole 4, i.e., inside the, or each, manhole 4.

[0030] Finally, the whole aircraft wing 2 with the cover are cured at once, e.g., in an autoclave.

[0031] The use of gaskets 5, preferably made from recycled polyamide by injection coming from recycled ancillary materials with the possibility improves compatibility, thermal stability, and adhesion to the wing 2, which is made of carbon composite.

[0032] The manufacturing by injection allows surface customization of the gaskets 5 to increase the mechanical joint with the composite material and avoid surface preparation, such as sanding.

[0033] Furthermore, the joint curing of the cover 1 and the wing 2 at once in a single cycle avoids the use of adhesive and a second secondary bonding process.

Claims

1. Method for applying a cover (1) to an aircraft wing (2), comprising the following steps: - placing a skin (3) provided with one or more manholes (4) on the aircraft wing (2); - placing a gasket (5) for the, or each, manhole (4) of the skin (3); - placing a plug (6) in the, or each, manhole (4); characterized in that the method also comprises: - curing the aircraft wing (2) with the cover (1), the cover (1) comprising the skin (3), the gasket or gaskets (5) and the plug or plugs (6).

2. Method for applying a cover to an aircraft wing according to claim 1, wherein the curing is made in an autoclave.

3. Method for applying a cover to an aircraft wing according to claim 1 or 2, wherein the, or each, gasket (5) is made from a thermoplastic material.

4. Method for applying a cover to an aircraft wing according to claim 3, wherein the, or each, gasket (5) is made from recycled polyamide.

5. Method for applying a cover to an aircraft wing according to claim 3 or 4, wherein the, or each, gasket (5) is made by injection.

6. Method for applying a cover to an aircraft wing according to any one of the previous claims, wherein the thickness of the, or each, plug (6) is adapted according to the thickness of the cover (1).

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