Aircraft tail

Abstract

An aircraft tailplane is disclosed, comprising: a rear fuselage section, an adjustable horizontal tail plane, the adjustable horizontal tail plane comprising a first lateral torsion box and a second lateral torsion box, each torsion box comprising a front wing spar and a rear wing spar, a front fitting and a rear fitting, an actuator acting on the front fitting for rotating the adjustable horizontal tail plane about a hinge axis passing through the rear fitting, the front fitting comprising a first front fitting unit and a second front fitting unit, the first and second front fitting units being connected to the front wing spars of the lateral torsion boxes, and the actuator comprising a first actuator unit and a second actuator unit, each actuator unit acting on the first and second front fitting units, respectively.

Description

Technical Field

[0001] The present invention relates to an aircraft tailplane including a tunable horizontal stabilizer actuator (THSA) configuration that allows more space in the pressurized section of the fuselage to accommodate passengers and / or cargo, while allowing the actuator to be accessed from outside the aircraft. Background Art

[0002] Commercial airliners have a horizontal tail plane (HTP) that rotates about a hinge line to modify the angle of attack depending on flight conditions.

[0003] It is known that a horizontal tail plane (HTP) may comprise two lateral torsion boxes, each lateral torsion box in turn comprising a front spar and a rear spar.

[0004] The horizontal tail plane (HTP) is usually attached to the fuselage via three fittings:

[0005] • Two fittings (called rear fittings) are located at the rear spar of the lateral torsion box. These two fittings are positioned symmetrically with respect to the vertical longitudinal symmetry plane of the aircraft. The articulation axis for the horizontal tail plane (HTP) rotation is orthogonal to this vertical longitudinal symmetry plane.

[0006] • One fitting (called the front fitting) is located at the front spar of the aircraft's lateral torsion box in the vertical longitudinal plane of symmetry.

[0007] It is also known to position a adjustable horizontal stabilizer actuator (THSA) positioned between the front fitting of the horizontal tail plane (HTP) and the fuselage. This actuator actuates the horizontal tail plane (HTP) in rotation about its articulation axis.

[0008] It is also known that a rear pressure bulkhead separates a pressurized section of the fuselage intended for carrying passengers and / or cargo from an unpressurized tail cone section of the fuselage.

[0009] The position of the rear pressure bulkhead is limited by the adjustable horizontal stabilizer actuator (THSA), so the tail configuration described above determines the position of the rear pressure bulkhead. The importance of providing more pressurized space to optimize the "operating" cost of commercial aircraft is undeniable.

[0010] Roughly below the actuator there is an access or maintenance door which has two main functions:

[0011] • Provides access to the Trimmable Horizontal Stabilizer Actuator (THSA).

[0012] • Provides replacement access for the Trimmable Horizontal Stabilizer Actuator (THSA).

[0013] The position of the rear pressure bulkhead is also limited by the position of the access door below the actuator.

[0014] In addition, known empennages include several access platforms or brackets located between the access door and the actuator to facilitate access to the actuator from the door and to provide a work platform for the operator at a reasonable distance and height from the THSA. These access platforms require construction and maintenance and add unnecessary extra weight to the aircraft. Summary of the Invention

[0015] The aircraft tail of the present invention comprises:

[0016] - A rear fuselage section comprising skin and frames.

[0017] - an adjustable horizontal tail plane comprising two lateral torsion boxes, in particular a first lateral torsion box and a second lateral torsion box. Each lateral torsion box in turn comprises a front spar and a rear spar.

[0018] - a front fitting and a rear fitting connected to the adjustable horizontal tail plane and to the fuselage section. In an embodiment, one end of the front fitting and the rear fitting are attached to the front and rear spars of the torsion box, respectively. The other ends of the fittings are connected to an intermediate element that connects the fittings to the fuselage section.

[0019] - an actuator configured to act on the front fitting for rotating the adjustable horizontal tail plane. The adjustable horizontal tail plane rotates about an articulation axis passing through the rear fitting (5) and orthogonal to the vertical longitudinal symmetry plane of the fuselage section. More specifically, the end of the front fitting is connected to the actuator, and the actuator is connected to the fitting, which in turn is connected to the fuselage section.

[0020] The horizontal tail plane is movable relative to the rear fuselage section in which it is at least partially housed. In particular, a central attachment between the port and starboard lateral torsion boxes is housed in the rear fuselage section and is movable relative to the rear fuselage section by means of actuators.

[0021] The front fitting object of the present invention comprises two fitting units, and the actuator comprises two actuator units. Each fitting unit is linked to a front spar of a lateral box, and each actuator unit is configured to act on a fitting unit.

[0022] The front fitting includes a first front fitting unit and a second front fitting unit. The first front fitting unit is coupled to the front spar of the first lateral box. The second front fitting unit is coupled to the front spar of the second lateral box. Similarly, the actuator includes a first actuator unit and a second actuator unit. The first actuator unit is configured to act on the first front fitting unit, and the second actuator unit is configured to act on the second front fitting unit.

[0023] The two actuators may be smaller than a single actuator in order to optimize the space required for actuation of the adjustable horizontal tail plane by using two smaller actuators instead of one.

[0024] Additionally, in an embodiment, the horizontal tail plane includes a sweep angle. A swept horizontal tail plane is a tail plane that is angled rearward from its vertical longitudinal plane of symmetry, rather than in a straight-side orientation. In this embodiment, the adjustable sweep angle of the horizontal tail plane allows the actuator to be positioned further aft relative to the longitudinal axis of the rear fuselage section. The longitudinal axis is the axis running along the length of the aircraft, i.e., the roll axis.

[0025] In another embodiment, the first actuator unit and the second actuator unit may be positioned behind the foremost point of the adjustable horizontal tail plane along the longitudinal axis of the rear fuselage section. Thus, the actuator units are positioned in the area between the foremost point of the horizontal tail plane and the horizontal tail plane itself.

[0026] Thus, due to the horizontal tail plane sweep, ie the adjustable horizontal tail plane is angled rearwardly from its root, the actuator can be positioned further rearwardly relative to the longitudinal direction of the aircraft. Due to the use of the horizontal tail plane sweep, space is freed up on the front side of the horizontal tail plane.

[0027] By these different configurations, the rear pressure bulkhead can be placed further aft of the aircraft, providing more space for the passenger and cargo compartments. In an embodiment, this position is limited by the forwardmost point of the adjustable horizontal tail plane, rather than by the position of the actuator.

[0028] In an embodiment, the fuselage section includes first and second access doors leading to the first and second front accessory units, the first and second access doors being located on opposite lateral sides of the aft fuselage section.

[0029] More specifically, the actuator units can be positioned adjacent to (not distant from) the fuselage skin, one for each lateral side of the fuselage section, allowing for rapid maintenance and replacement tasks from the outside of the aircraft. In fact, the distance between the fuselage lateral skin and the actuator units of the present invention can be within easy reach, for example, approximately or less than the average human arm's length. Consequently, an operator does not need to enter the fuselage section to perform maintenance or replacement of the actuator units. Thus, the access door allows maintenance and replacement tasks to be performed from the outside of the aircraft.

[0030] The above embodiment provides faster maintenance access because the actuator maintenance tasks do not need to enter the aircraft.In addition, because these maintenance platforms are not necessary for the adjustable horizontal tail plane actuator maintenance, the maintenance platforms can be removed.

[0031] In addition, as mentioned above in the prior art, the lower door also restricts the movement of the rear pressure bulkhead, but in this embodiment, the lower door is removed.

[0032] According to the above, the present invention provides three main improvement solutions:

[0033] -By optimizing the space required for the adjustable horizontal tailplane actuators, additional space is provided for the passenger and cargo compartments.

[0034] - Provides easier and faster access for servicing tasks on the adjustable horizontal tailplane actuator.

[0035] - Removal of the maintenance platform located between the actuator and the maintenance door, reducing aircraft weight and reducing manufacturing and maintenance costs.

[0036] In addition, the adjustable horizontal tail plane actuator system will be redundant and safer since there are two actuator units instead of one.In addition, each actuator unit may include a clutch that disengages in the event of a fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To complete the description and to facilitate a better understanding of the present invention, a set of accompanying drawings is provided. The accompanying drawings form an integral part of the specification and illustrate preferred embodiments of the present invention. The accompanying drawings include the following figures.

[0038] Figure 1 A schematic side view of an aircraft tail fin known from the prior art is shown.

[0039] Figure 2 Shown Figure 1 Schematic plan view of an aircraft tail wing known in the prior art.

[0040] Figure 3 Shown Figure 1 A perspective side view of an aircraft tail wing known in the prior art.

[0041] Figure 4 A schematic side view of an embodiment of an aircraft tail fin according to the invention is shown.

[0042] Figure 5 Shown Figure 4 Schematic plan view of an embodiment of the present invention.

[0043] Figure 6 A perspective side view of an embodiment of an aircraft tail fin is shown.

[0044] Figure 7 A schematic plan view of an embodiment of an aircraft tail fin is shown. DETAILED DESCRIPTION

[0045] Figures 1 to 3 The invention discloses the known tail fins in the prior art. The known tail fins include:

[0046] - The rear fuselage section 1, which comprises the skin 1.1 and the frames. It may include other internal reinforcements.

[0047] An adjustable horizontal tail plane 2 comprising two lateral torsion boxes 21 , 22 . Each lateral torsion box 21 , 22 comprises a front spar 211 , 221 and a rear spar 212 , 222 .

[0048] - a front fitting 4 and a rear fitting 5 connected to the adjustable horizontal tail plane 2 and to the fuselage section 1. The front fitting 4 is located in the symmetry centre of the tail.

[0049] - an actuator 3 , which is linked to the front fitting 4 and is used to rotate the adjustable horizontal tail plane 2 about the hinge axis 11 . The actuator 3 is also linked to a fitting attached to the fuselage section 1 .

[0050] Figure 3 An access platform 6 is shown between the actuator 3 and an access door 7 located in the lower region of the fuselage section 1 .

[0051] Figure 4 and Figure 5 An embodiment is disclosed wherein the actuator 3 comprises first and second actuator units 31, 32 and the front fitting 4 comprises first and second front fitting units 41, 42. Each front fitting unit 41, 42 is linked to the front spar 211, 221 of the lateral torsion box 21, 22.

[0052] Figure 4 and Figure 5 Also disclosed:

[0053] - Rear fuselage section 1,

[0054] an adjustable horizontal tail plane 2 comprising a first and a second lateral torsion box 21 , 22 comprising a front spar 211 , 221 and a rear spar 212 , 222 ,

[0055] - a rear fitting 5 connected to the adjustable horizontal tail plane 2, and

[0056] - Articulation axis 11 .

[0057] As can be seen in the figure, the horizontal tail plane 2 comprises a sweep angle which allows placing the actuator units 31 , 32 in a more rearward position with respect to the position of the actuator 3 in the prior art.

[0058] In the embodiment shown, the first and second actuator units 31, 32 are located behind the foremost point 8 of the adjustable horizontal tail plane 2 on the longitudinal axis of the rear fuselage section 1. The first and second actuator units 31, 32 are located between the first and second front spars 211, 221 of the lateral torsion boxes 21, 22, respectively, and the skin 1.1 of the rear fuselage section 1.

[0059] In this embodiment, the position of the rear pressure bulkhead 10 is limited by the forwardmost point 8 of the adjustable horizontal tail plane 2, rather than by the positions of the actuator units 31, 32 as in the prior art. The forwardmost point 8 of the adjustable horizontal tail plane 2 corresponds to the forward point of the connection between the first lateral torsion box 21 on the starboard side and the second lateral torsion box 22 on the port side.

[0060] Figure 4 and Figure 5 The position 10 . 1 of the rear pressure bulkhead in the prior art configuration is also shown in dashed lines.

[0061] The skin 1 . 1 of the fuselage section 1 comprises two access doors 71 , 72 , a first access door and a second access door 71 , 72 being located on opposite lateral sides of the rear fuselage section 1 .

[0062] The central area of ​​the lateral sides of the rear fuselage section 1 is flatter in proportion to the lower area, so this position simplifies the shape and arrangement of the access doors.

[0063] The first and second access doors 71 , 72 are sized to allow maintenance and to allow spare parts to be removed or introduced in the rear fuselage section 1 in order to facilitate assembly and maintenance of the aircraft.

[0064] More specifically, the first and second actuator units 31 , 32 are positioned adjacent to the skin 1 . 1 of the rear fuselage section 1 so that maintenance and replacement tasks can be performed from outside the aircraft through access doors 71 , 72 .

[0065] exist Figure 7 In the illustrated embodiment, the first and second front fitting units 41, 42 comprise elongated support rods. These are attached at one end to the front spars 221, 211 and at the other end to the actuator units 31, 32. The support rods lie in a plane perpendicular to the front spars 221, 211, pointing toward the lateral sides of the rear fuselage section 1. The adapted length of the support rods allows the actuator units 31, 32 to be placed as close to the skin 1.1 as possible, simplifying maintenance and manufacturing.

[0066] Preferably, the two actuator units 31 , 32 are located in the same longitudinal section of the fuselage section 1 on an axis parallel to the pitch axis “Y” of the aircraft.

[0067] In the embodiment shown, each actuator unit 31, 32 is positioned below or above each of the front fitting units 41, 42 relative to the Z axis of the aircraft's tailplane, which is parallel to the aircraft's yaw axis. Thus, the actuator units 31, 32 perform linear movements to act on the horizontal tailplane.

[0068] The two actuator units 31, 32 are attached to the lower or upper portion of an internal reinforcement member (e.g., a frame) so that they are positioned above or below the HTP relative to the Z-axis of the aircraft's tail. This leaves the lateral sides of the tail section 1 free of attachments, allowing access to the actuator units 31, 32 from the lateral sides of the tail. The location of the lower area provides good access for maintenance.

Claims

1. An aircraft tail wing, comprising: A rear fuselage section (1), comprising a skin (1.1) and a frame, An adjustable horizontal tail plane (2), the adjustable horizontal tail plane comprising a first lateral torsion box and a second lateral torsion box (21, 22), the first lateral torsion box and the second lateral torsion box (21, 22) comprising a front spar (211, 221) and a rear spar (212, 222), a front fitting (4) and a rear fitting (5), said front fitting and said rear fitting being connected to said adjustable horizontal tail plane (2) and to said fuselage section (1), an actuator (3) configured to act on the front fitting (4) for rotating the adjustable horizontal tail plane (2) about an articulation axis (11) passing through the rear fitting (5) and being orthogonal to the vertical longitudinal symmetry plane of the fuselage section (1), It is characterized by: The front fitting (4) comprises a first front fitting unit and a second front fitting unit (41, 42), the first front fitting unit (41) being connected to the front spar (211) of the first lateral torsion box (21), and the second front fitting unit (42) being connected to the front spar (221) of the second lateral torsion box (22), wherein the first front fitting unit (41) and the second front fitting unit (42) comprise elongated support rods, the elongated support rods being located in a plane perpendicular to the front spar (211, 221) and the elongated support rods being directed towards the lateral side of the rear fuselage section (1), and The actuator (3) comprises a first actuator unit and a second actuator unit (31, 32), the first actuator unit (31) being configured to act on the first front accessory unit (41), and the second actuator unit (32) being configured to act on the second front accessory unit (42).

2. The aircraft tail fin according to claim 1, wherein: The horizontal tail plane (2) includes a sweep angle.

3. The aircraft tail wing according to claim 1 or 2, wherein: The first actuator unit and the second actuator unit (31, 32) are located behind a forwardmost point (8) of the adjustable horizontal tail plane (2) on the longitudinal axis of the rear fuselage section (1).

4. The aircraft tail wing according to claim 1 or 2, wherein: The fuselage section (1) comprises a first access door (71) leading to the first front fitting unit (41) and a second access door (72) leading to the second front fitting unit (42), the access doors (71, 72) being located on opposite lateral sides of the rear fuselage section (1).

5. The aircraft tail wing according to claim 1 or 2, wherein: The first and second actuator units (31, 32) are positioned adjacent to a skin (1.1) of the rear fuselage section (1).

6. The aircraft tail fin according to claim 1 or 2, wherein: The first actuator unit and the second actuator unit (31, 32) are located in the same longitudinal section of the fuselage section (1) on an axis parallel to the pitch axis of the fuselage section (1).

7. The aircraft tail fin according to claim 1 or 2, wherein: Each of the first actuator unit and the second actuator unit (31, 32) is located below or above each of the front accessory units (41, 42) relative to the Z axis of the aircraft tail wing.

8. The aircraft tail fin according to claim 1 or 2, wherein: The first actuator unit and the second actuator unit (31, 32) are attached to a lower part or an upper part of a frame.

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