GB2526089A

GB2526089A - Aircraft fuel cap

Info

Publication number: GB2526089A
Application number: GB1408391.9A
Authority: GB
Inventors: George Edmond; Robert Case
Original assignee: Airbus Operations Ltd
Current assignee: Airbus Operations Ltd
Priority date: 2014-05-12
Filing date: 2014-05-12
Publication date: 2015-11-18
Anticipated expiration: 2034-05-12
Also published as: GB2526089B; GB201408391D0

Abstract

An aircraft assembly having an aerodynamic surface, the assembly including a fuel tank having a refuel opening 60 within a recess 52 of the aerodynamic surface, and a hinged access door 70 having a closed position in which it encloses the recess and an open position in which the recess is accessible. The inner surface 76 of the access door 70 carries a fuel cap 80 integrated with the access door such that in the closed position, the fuel cap 80 covers the refuel opening 60 but in the open position the fuel cap is remote from the refuel opening to allow access to the refuel opening.

Description

AIRCRAFT FUEL CAP

FIELD OF THE INVENTION

[0001] The present invention relates to an aircraft fuel cap, and more particularly to an aircraft fuel cap for use with a re-fuel opening located within a recess in an aerodynamic surface of the aircraft.

BACKGROUND OF THE INVENTION

[0002] It is a requirement of civil aviation regulations such as JAR (Joint Aviation Regulations), FAR (Federal Aviation Regulations), and those set by EASA (European Aviation Safety Agency), that the access point for a fixed wing aircraft's fuel/refuel system is protected from contamination by the presence of a cover or cap.

A typical fuel/refuel system, such as that shown in Fig. 1, comprises a refu& opening (which may comprise an access adaptor) which provides an interface for insertion of a fuel bowser (not shown) for the purposes of refuelling. A fuel cap 20 seals the refuel opening when refuelling is not taking place; the term fuel cap being used to describe any cover, lid, crown or closure that provides an operational environmental protection.

[0003] In order to avoid direct exposure of the fuel cap and refuel opening to the airflow duing flight, these parts are located within a recess (not shown) in the aerodynamic surface, the recess being endosed by a movable access door or access panel (not shown) which itself forms a part of the aerodynamic surface.

[0004] Typically, the fuel cap 20 is attached to the refuel opening 10, or nearby stmcture, by a lanyard 30. Thus, when the fuel cap 20 is removed to permit refuelling it dangles beneath the refuel opening as shown in Fig. 1. A problem with this arrangement is that the dangling fuel cap 20 obstructs and inhibits the attachment of the fuel bowser to the refuel opening. Another problem is that during high winds the dangling fuel cap 20 may swing to such an extent that it damages the access panel or other surrounding structure. A known solution to these problems is to cut the lanyard so that the fuel cap 20 can be temporarily stored elsewhere, with a consequent risk of the fuel cap becoming lost. Moreover, this solution does not provide a failsafe mechanism to prevent the access door being closed without the refuel opening being re-sealed by the fuel cap.

[0005] One proposed solution to solve the above-mentioned problems is disclosed in GB2506732. That solution involves providing an assembly with a support bracket located on the inner surface of the access door, The support bracket receives the fuel cap when the access door is open. The bracket is arranged such that the access door cannot be closed unless or until the cap has been replaced on the refuel opening.

[0006] A problem with the above-mentioned proposal is that the assembly still comprises a relatively large number of different parts, and therefore has a correspondingly high cost associated with it, Furthermore, the solution is still relatively complex to operate, and the fuel cap could, in principle, still be misplaced if it is not inserted in the support bracket after removal from the re-fuel opening. If that did occur, the access door could, in principle, be closed without the fuel cap having correctly been replaced.

SUMMARY OF THE INVENTION

[0007] According to a first aspect of the invention, there is provided an aircraft assembly having an aerodynamic surface, the assembly including: a fuel tank having a refuel opening within a recess of the aerodynamic surface; and a hinged access door having a closed position in which it encloses the recess and an open position in which the recess is accessible, the access door having an outer surface and an inner surface, the outer surface being arranged to fonn a part of the aerodynamic surface in the closed position; and characterised in that the inner surface of the access door carries a fuel cap integrated with the access door such that in the closed position, the fuel cap covers the refuel opening but in the open position the fuel cap is remote from the refuel opening to allow access to said refuel opening.

[0008] By integrating the fuel cap with the access door, the present invention reduces the complexity and the number of separate parts involved in the assembly.

This tends to simplify any repair, installation or adaptation of the assembly if and when required. Furthermore, the operations of removing and replacing the fuel cap are greatly simplified because they are inherently performed when the access door is opened and closed respectively. The present invention may thus ensure that if the door is closed, the fuel cap is correctly in position (and vice versa), as well as providing a relatively simple, and intuitive to use, assembly for the user.

[0009] The inner surface of the access door carries a fuel cap integrated with the access door, It will be appreciated that the fuel cap being carried on the access door encompasses the possibility of the cap being (detachably or fixedly) coupled to the inner surface of the access door, or being integrally formed as part of a monolithic access panel.

[0010] The fuel cap may comprise a sealing wall protruding from the inner surface of the access door, the sealing wall being arranged to surround the refuel opening when the access door is in the closed position. The sealing wall preferably forms a perimeter wall around the re-ftiel opening when the access door is in the closed position. The sealing wall may be in the form of a ring. The sealing wall may be resiliently deformable. Such an arrangement may improve the effectiveness of the protection provided by the fuel cap and reduces the need for high tolerances in the assembly (which may otherwise be required if the wall were a rigid structure).

[0011] The fuel cap may comprises a cover portion for covering the refuel opening when the access door is in the closed position. The covering portion is preferably formed by the inner surface of the access door.

[0012] The access door is preferably hinged on a double hinge to allow two-stage movement of the access door as it is moved between its open and closed positions.

Such an arrangement is beneficial because it can facilitate a positive attachment of the fuel cap over the re-fuel opening. A double hinge may also extend the opening angle of the access door, creating improved access for a fuel bowser.

[0013] The assembly may comprise a biasing member which, when the access door is in the closed position, is arranged to bias the access door into maintaining said closed position. Alternatively, or additionally, the assembly may comprise a biasing member (or further biasing member) which, when the access door is in the open position, is arranged to bias the access door into maintaining said open position.

[0014] The invention may be applied to in-service aircraft by simple attachment of the fuel cap to the access door, or by attachment of a replacement access door according to the invention. The low part count and simple nature of the invention are particularly advantageous features when applied as a retro-fit or forward-fit solutions.

1100t5] The fuel cap may comprise one or more reinforcement portions arranged to provide stmctural stiffness to the access door. Thus, the fuel cap may perform the dual roles of covering the re-fuel opening and providing structural rigidity to the access door. Such an arrangement may save weight (an important consideration in aircraft assemblies), since it may not be necessary to provide the access door with additional stiffening members, or the number of additional stiffening members may be reduced.

[00t6] The aerodynamic surface may form part of a lower surface of a wing.

[00t7] The access door may move downwardly away from the aerodynamic surface as it is moved from the closed position to the open position.

[00t8] In the closed position the door may have a generally horizontal onentation.

[0019] A further aspect of the invention provides an access door for an aircraft having an aerodynamic surface, the aircraft including a fuel tank having a refuel opening within a recess of the aerodynamic surface, wherein the access door is capable of having a closed position in which it encloses the recess and an open position in which the recess is accessible, the access door having an outer surface and an inner surface, the outer surface being arranged to form a part of the aerodynamic surface in the closed position and characterised in that the inner surface of the access door carries a fuel cap integrated with the access door such that in the closed position, the fuel cap covers the refuel opening but in the open position the fuel cap is remote from the reftiel opening to allow access to said refuel opening.

[0020] According to yet another aspect of the invention there is provided a method of re-fuelling an aircraft, the aircraft having an aerodynamic surface, a fuel tank having a refuel opening within a recess of the aerodynamic surface, and a hinged access door having a closed position in which it encloses the recess and an open position in which the recess is accessible, wherein the method comprises the steps of: moving the access door from the closed position to the open position, said movement being arranged to effect removal of a fuel cap from the re-fuel opening thereby allowing access to the re-fuel opening; and re-fuelling the aircraft via the re-fuel opening.

[0021] The method may comprise the subsequent step of moving the access door from the open position to the closed position, said movement being ananged to effect replacement the fuel cap onto the re-fuel opening. By integrating the step of moving the access door between the open and closed positions, with the removal/replacement of the fuel cap, the present invention provides a simple and intuitive method of re-fuelling the aircraft.

[0022] It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. For example, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa,

BRIEF DESCRWTION OF THE DRAWINGS

[0023] Embodiments of the invention will now be described with reference to the accompanying drawings, in which: [0024] Fig. I shows an example of prior art refuel apparatus; [0025] Fig. 2 is a schematic plan view of an aircraft wing showing a location of refuel apparatus according to an embodiment of the invention; and [0026] Fig. 3 shows an example of refuel apparatus according to an embodiment of the invention,

DETAILED DESCRIPTION OF EMBODIMENT(S1

[0027] As shown in Fig. 2, known fixed wing aircraft have a re-fuel location 40 located at a lower surface of a wing thereof Fig, 2 shows the re-fuel location 40 on the left (port) wing, but it is most usually located on the right (starboard) wing, Some aircraft have two re-fuel locations 40, one on each wing, [0028] Fig. 3 shows the equipment provided at each re-fuel location 40, in accordance with an embodiment of the invention. The lower aerodynamic wing surface 50 is interrupted by a recess 52 having a generally rectangular access opening.

Within the recess 52 is a refuel opening 60 which is in fluid communication with a fuel tank (not shown) within the wing. Thus, a fuel bowser (not shown) can be connected to the refuel opening 60 to deliver fuel to the fuel tank, [0029] M access door 70 comprising a generally planar panel is pivotally attached via a hinge 72 to a peripheral edge of the access opening of the recess 52.

Thus, the access door 70 can move downwardly away from the aerodynamic surface so as to hang open (as shown in Fig. 3) to permit access to the refuel opening 60, or can be closed to enclose the recess 52 and complete the lower aerodynamic wing surface 50, A pair of catches 74 act to secure the access door 70 in the closed position. The access door 70 pivots about the hinge 72 as it is moved between its open and closed positions. In the closed position the door has a generally horizontal onentation.

[0030] The access door 70 has an inner surface 76 and an outer surface (not visible in Figure 3). The inner surface 76 carries a fuel cap 80. The fuel cap 80 comprises a rubber sealing ring 82 protruding from the inner surface 76, and a cover region 84 formed by the part of the inner surface 76 located within the sealing ring 82.

[0031] The fuel cap 80 is positioned in the centre of the access door 70 such that in the closed position, the ring 82 surrounds the refuel opening 60 in a tight fit, and the cover region 84 covers the top of the re-fuel opening 60, The fuel cap thus protects the re-fuel opening 60 from the surrounding environment when the access door 70 is in the closed position. However, when the access door 70 is in the open position (Fig 3), the friel cap 80 is remote from the re-fuel opening 60 and access to the re-fuel opening by a fuel bowser is enabled, [0032] As will be appreciated from the above-description, the inner surface 76 of the access door 70 thus carries a fuel cap 80 integrated with the access door 70 such that in the closed position, the fuel cap 80 covers the refuel opening 60 but in the open position the fuel cap 80 is remote from the refuel opening 60 to allow access to said refuel opening.

[0033] By integrating the fuel cap 80 with the access door 70, the operations of removing and replacing the fuel cap are greatly simplified because they are inherently performed when the access door is opened and closed respectively. The present invention thus ensures that if the door is closed, the fuel cap is correctly in position, and v/ce versa (i.e. if the door is not closed, there is a clear indication that the fuel cap is not correctly in place). The assembly is also relatively simple, and intuitive to use, with relatively few separate parts, [0034] In the first embodiment of the invention, the hinge 72 is a double-hinge.

This allows two-stage movement of the access door as it is moved between its open and closed positions, and facilitates a positive engagement attachment of the rubber sealing ring 82 cap over the re-fuel opening. The double hinge 72 also extends the opening angle of the access door 70, creating improved access for a fuel bowser.

[0035] In a further embodiment of the invention (not shown), the fuel cap includes reinforcing members, which act to stiffen the access door. In this further embodiment, the assembly also includes a spring, which, when the access door is in the open position, is arranged to bias the access door into maintaining said open position. Such an arrangement ensures the door is kept fully open during re-fuelling and does not interfere with the fuel bowser.

[0036] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein, Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents, It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

CLAIMSI. An aircraft assembly having an aerodynamic surface, the assembly including: a fuel tank having a refuel opening within a recess of the aerodynamic surface; and a hinged access door having a closed position in which it encloses the recess and an open position in which the recess is accessible, the access door having an outer surface and an inner surface, the outer surface being arranged to form a part of the aerodynamic surface in the closed position; and characterised in that the inner surface of the access door carries a fuel cap integrated with the access door such that in the closed position, the fuel cap covers the refuel opening but in the open position the fuel cap is remote from the refuel opening to allow access to said refuel opening.
2. An assembly according to claim t, wherein the fuel cap comprises a sealing wall protruding from the inner surface of the access door, the sealing wall being arranged to surround the refuel opening when the access door is in the closed position.
3. An assembly according to claim t or claim 2, wherein the fuel cap comprises a cover portion for covering the refuel opening when the access door is in the closed position.
4. An assembly according to claim 3, wherein the cover portion is formed by the inner surface of the access door.
5. An assembly according to any preceding claim, wherein the access door is hinged on a double hinge to allow two-stage movement of the access door as it is moved between its open and closed positions.
6. An assembly according to any preceding claim, wherein the assembly comprises a biasing member which, when the access door is in the closed position, is arranged to bias the access door into maintaining said closed position.
7. An assembly according to any preceding claim, wherein the assembly comprises a biasing member which, when the access door is in the open position, is arranged to bias the access door into maintaining said open position.
8. An assembly according to any preceding claim, wherein the fuel cap comprises one or more reinforcement portions arranged to provide structural stiffness to the access door.
9. An assembly according to any of claims I to 8, wherein the aerodynamic surface forms part of a lower surface of a wing.
10. An assembly according to any of claims I to 9, wherein the access door moves downwardly away from the aerodynamic surface as it is moved from the closed position to the open position.
11. An access door for an aircraft having an aerodynamic surface, the aircraft including a fuel tank having a refuel opening within a recess of the aerodynamic surface, wherein the access door is capable of having a closed position in which it encloses the recess and an open position in which the recess is accessible, the access door having an outer surface and an inner surface, the outer surface being arranged to form a part of the aerodynamic surface in the closed position and characterised in that the inner surface of the access door carries a fuel cap integrated with the access door such that in the closed position, the fuel cap covers the refuel opening but in the open position the fuel cap is remote from the refuel opening to allow access to said refuel opening.
12. A method of re-fuelling an aircraft, the aircraft having an aerodynamic surface, a fuel tank having a refuel opening within a recess of the aerodynamic surface, and a hinged access door having a closed position in which it encloses the recess and an open position in which the recess is accessible, wherein the method comprises the steps of: (a) moving the access door from the closed position to the open position, said movement being aranged to effect removal of a fuel cap from the re-fuel opening thereby allowing access to the re-fuel opening; and (b) re-fuelling the aircraft via the re-fuel opening.
13. A method according to claim 12, comprising the subsequent step of (c) moving the access door from the open position to the closed position, said movement being arranged to effect replacement the fuel cap onto the re-fuel opening.