AIRCRAFT FUSELAGE SECTION INCORPORATING A DYNAMIC HARNESS

Abstract

A harness routing electrically connects a rear fuselage section of an aircraft and a trimmable Horizontal Tail Plane (HTP) installed at this rear section. The aircraft rear section includes a first clipping point wherein the harness is attached to a fuselage frame located in front of the torsion box front spar, and a second clipping point wherein the harness is attached to a front spar of the HTP torsion box. The second clipping point is located downstream the first clipping point from the fuselage towards the torsion box interior, and the harness passes through the front spar towards the interior of the torsion box downstream the second clipping point. The harness installation and routing is optimized, in order to reduce harness length and weight, but at the same time assuring that any damage to the harness cables are prevented during the entire aircraft operative life.

Claims

1. An aircraft rear section comprising: a fuselage section incorporating a plurality of frames; a torsion box installed at the fuselage section, wherein the torsion box has a front spar and a rear spar, and wherein the torsion box is trimmable about a rotation axis coupled to the rear spar; a cables harness having a portion fixed to the fuselage section and a portion extending through the torsion box interior, such as the harness is flexed with the movement of the torsion box; a first clipping point wherein the harness is attached to a fuselage frame located in front of the torsion box front spar; and a second clipping point wherein the harness is attached to the front spar, wherein the second clipping point is located downstream the first clipping point from the fuselage towards the torsion box interior, and the harness passes through the front spar towards the interior of the torsion box downstream the second clipping point.

2. The aircraft rear section according to claim 1, wherein each of said clipping points has an axis, and wherein the axis of the first clipping point forms an angle (β) in a top plan view with the rotation axis within the range (40°-50°), and wherein the axis of the second clipping point is parallel to the front spar.

3. The aircraft rear section according to claim 2, wherein the angle (β) is 45°.

4. The aircraft rear section according to claim 1, wherein the second clipping point has a ring-shaped clamp fixed to the front spar, and a tubular sleeve fitted inside the clamp such as the tubular sleeve is rotatable inside the clamp, and wherein the harness is placed and fixed inside the tubular sleeve.

5. The aircraft rear section according to claim 1, wherein the harness is fixed at first clipping point.

6. The aircraft rear section according to claim 1, further comprising a third harness clipping point fixed at the front spar, and located downstream the second clipping point.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Preferred embodiments of the invention, are henceforth described with reference to the accompanying drawings, wherein:

[0035] FIG. 1 shows a schematic representation of a classical harness routing at a fuselage rear section according to the prior art.

[0036] FIG. 2 shows a schematic representation of a harness routing at a fuselage rear section according to an embodiment of the invention.

[0037] FIG. 3A shows a harness installation at a real HTP according to the prior art and FIG. 3B shows a harness installation at a real HTP according to an embodiment of the invention.

[0038] FIGS. 4A-4B show schematic representations of the installation angles for the harness according to an embodiment of the invention. The dotted lines are parallel to the rotation axis. Only one harness is represented for the sake of simplicity of the figure. The drawings shown the torsion box in its horizontal position.

[0039] FIG. 5A shows a detailed representation of harnesses portions fitted to a front spar of a torsion box and FIG. 5B is an enlarged detail extracted from FIG. 5A.

[0040] FIG. 6 shows the movement and angles of a harness arranged according to an embodiment of the invention.

DETAILED DESCRIPTION

[0041] FIG. 2 shows schematically an aircraft rear section comprising a fuselage section (1) incorporating a left frame (7a) and a right frame (7b), and a torsion box (2) of an HTP installed at the fuselage section (1). The torsion box (2) has a left front spar (3a) and a right front spar (3b), and left rear spar (8a) and a right front spar (8b), and it is trimmable about a rotation axis (4) coupled to the rear spars (8a,8b).

[0042] Left and right cables harnesses (5a,5b) have a portion fixed to the fuselage section (1), in particular to the left and right frames (7a,7b) respectively, by means of left and right first clipping points (5a2,5b2). As it can be noted in FIG. 2, these fuselage frames (7a,7b) are located in front of the torsion box front spars (3a,3b).

[0043] The harnesses (5a,5b) are then attached to the front spars (3a,3b) respectively at left and right second clipping points (5a1,5b1), wherein the second clipping points (5a1,5b1) are located downstream the first clipping points (5a2,5b2). Downstream the second clipping points, the harnesses passes through the front spars (3a,3b) towards the interior of the torsion box (2).

[0044] For this new arrangement of the harnesses in front of the torsion box, it has been found a balance between an optimized electrical installation and to keep the path of the dynamic length of harnesses as close as possible to a plane. Furthermore, the torsion efforts which now appear at the dynamic harness, have been mitigated during the whole extend of the trimming operation.

[0045] A preferred solution is shown in FIG. 4 wherein it can be noted that the axis (x1) of the first clipping point (5a2) forms an angle (β) (in a top plan view) with respect to the rotation axis (4), and that angle (β) is within the range (40°-50°), preferably 45°. This angle has been defined taken into account that if β increases, the behaviour of dynamic harness improves (less torsion), but a bigger and therefore heavier clamp and structure would be needed to fix the harness to the frame.

[0046] Additionally, the axis (x2) of the second clipping point (5a1) is parallel to the front spar which is a straight element. Alternatively, it can be defined that the second clipping point (5a1) forms an angle (α) (in a top plan view) with respect to the rotation axis (4), and that angle (α) is about 35°.

[0047] The first clipping points (5a2,5b2) include one support which contain two p-clamps and the harness is fixed to these clipping points. However, as shown in FIG. 5 the second clipping point (5a1) which includes two support (which contain two p-clamps per support) fixed to the left front spar (3a). The support (5a1) incorporates a tubular sleeve (9) fitted inside the clamps (10,10′) such as the tubular sleeve (9) is rotatable inside the clamps (10,10′). The sleeve (9) is placed around and co-axially with the harness and it is fixed to the harness. The sleeve (9) increases the dynamic length of the harness by allowing rotation of the harness inside the clipping point.

[0048] The sleeve (9) has some annular protrusions (11,11′) on its outer surface and in contact with the edges of the clamps (10,10′), such as the sleeve (9) cannot move axially with respect to the clamps (10,10′).

[0049] As shown in drawing 4B, downstream the second clipping point (5a1), there is a third harness clipping point (5a3) fixed to the front spar (3a), and from here the harness passes through the front spar (3a) to the torsion box interior. At the third clipping point (5a3) the torsion effect disappear, and terminate the dynamic length of the harness.

[0050] The movement of the dynamic harness caused by the movement of the HTP, is represented in FIG. 6. It is assured that the dynamic harness can move from the maximum upper position to the maximum bottom position of the HTP. A Trimmable Horizontal Stabilizer Actuator (THSA) moves the HTP at the center of the front spars. The range of THSA in the aircraft introduce an angles change that goes from −0.8° to −13.7° in vertical axis (overstroke is not included), as shown in FIG. 6. This range produces an angle of 80 degrees in the fixed clipping point at the fuselage frame.

[0051] Other preferred embodiments of the present invention are described in the appended dependent claims and the multiple combinations thereof.

[0052] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.