Tail unit of an aircraft with horizontal stabilizers meeting at the root of the vertical stabilizer

Abstract

An aircraft tail section comprises: - a vertical tail; - an aft fuselage section attached to the vertical tail and comprising a skin and internal stiffening members; - a horizontal tail comprising two lateral torsion boxes and a frame structure between the two lateral torsion boxes, the frame structure comprising a front spar, a rear spar and two ribs extending between the front spar and the rear spar, and each rib being adjacent a lateral torsion box. The frame structure encloses a portion of the vertical tail along a spanwise direction of the vertical tail. The aircraft tail section comprises an attachment assembly attaching the frame structure to the aft fuselage section, the attachment assembly crossing the skin and extending between the internal stiffening members of the aft fuselage section and the frame structure.

Description

Technical Field

[0001] This invention relates to a tail section or tail configuration of an aircraft. The tail section includes a horizontal tail (HTP) located at the root region of the vertical tail (VTP). Background Technology

[0002] The tail section (also known as the tail, tail assembly, or tail configuration) is the structure at the rear of an aircraft that provides stability during takeoff and flight.

[0003] The tail section is the entire tail structure and includes the rear fuselage, the vertical stabilizer or vertical tail (VTP), and the horizontal stabilizer or horizontal tail (HTP). The tail section also includes the rudder and elevator.

[0004] Optimization of wet surfaces, as well as the weight and size of the horizontal tail (HTP) and vertical tail (VTP), are related to improving aircraft performance.

[0005] Various configurations of tail assemblies can be found in the literature on commercial and defense aircraft. The three most relevant tail assemblies are explained below: conventional, T-tail, and cruciform tail.

[0006] Although the position of the vertical tail (VTP) is the same in all three configurations mentioned, the position of the horizontal tail (HTP) varies from the top of the vertical tail (VTP) structure to the middle section of the rear fuselage.

[0007] These locations not only alter the aerodynamics of the entire aircraft but also affect the rear fuselage and vertical tail (VTP) structure. The area where the horizontal tail (HTP) is attached must be reinforced, thus increasing the aircraft's weight and cost.

[0008] Standard tail

[0009] The conventional tail is the most common tail configuration in commercial aircraft. This type of tail includes a vertical tail (VTP) integrated into the upper region of the aft fuselage. The horizontal tail (HTP) is attached to an internal structure of the aft fuselage.

[0010] The horizontal stabilizer (HTP) is attached to the middle section of the rear fuselage through several fittings and structural rods connected to the inner frame of the rear fuselage.

[0011] Since the horizontal stabilizer (HTP) is typically trimmable, it is necessary to modify the rear fuselage at the interface with the HTP to allow for its movement, as follows:

[0012] A prominent cutout was required in the aft fuselage to position the horizontal stabilizer (HTP) and provide sufficient clearance to avoid any impact during its trim movement. Several reinforcements were implemented as beams and high-load frames to reinforce the cutout and redistribute the load.

[0013] • The final frame of the aft fuselage remains open to allow the horizontal stabilizer (HTP) to be introduced into the aft fuselage during final assembly operations. This is detrimental to the structural efficiency of the aft fuselage. The final frame is enclosed by a lattice structure to meet interchangeability requirements for replacing the horizontal stabilizer (HTP), if necessary.

[0014] • The aerodynamic profile of the rear fuselage is modified around the cutout. The hyperbolic region is implemented to be compatible with the trim motion of the horizontal tail (HTP). The hyperbolic region also minimizes parasitic aerodynamic drag due to the partial mounting of the fairing.

[0015] The main disadvantages of a conventional tail section in terms of aircraft structure, purpose, and aerodynamics are:

[0016] Because the connection between the horizontal stabilizer (HTP) and the aft fuselage is made inside the fuselage, a large portion of the HTP is hidden within the aft fuselage. This hidden portion is not useful for aircraft control. Therefore, the overall size of the HTP is increased to compensate for this undampened area, thereby reducing component drag, weight, and cost.

[0017] • Because the horizontal stabilizer (HTP) is partially located inside the aft fuselage, this fuselage section is significantly impacted in terms of weight and cost due to the need for additional structural reinforcements to redistribute the load around the cut-out area. Furthermore, the use of a strut structure within the closed frame, due to the interchangeability requirements of the HTP, is not the optimal solution in terms of weight.

[0018] • The manufacturing and assembly of the rear fuselage are adversely affected by the high complexity involved in the production process of the hyperbolic shape around the cut area.

[0019] Furthermore, using the fuselage interior to house the horizontal stabilizer (HTP) junction eliminates the possibility of using that space for other purposes, such as auxiliary power unit (APU) placement, passenger boarding, or system allocation. This reduces the aircraft's effective capacity and necessitates a larger fuselage to accommodate these components, thus impacting drag, weight, and cost.

[0020] • Due to the low position of the horizontal stabilizer (HTP), the likelihood of impacts with various objects projected from the runway and accidents during ground operations is higher than in other tail configurations.

[0021] T-shaped tail

[0022] The T-tail configuration is used when the engine is located in the tail cone, or the wing is positioned high up, or when space inside the rear fuselage is required.

[0023] In this configuration, the horizontal tail fin (HTP) is attached to the upper part of the vertical tail fin (VTP), thus creating the T-shape that gives this configuration its name.

[0024] The main disadvantage of the T-tail configuration is:

[0025] The placement of the horizontal stabilizer (HTP) at the top of the vertical stabilizer (VTP) represents an increase in the load that the VTP must bear. Firstly, because the weight and load of the HTP must be borne by the VTP structure. Secondly, because the distance of the pivot point within the truncationable HTP is much smaller due to the HTP's attachment being located in the narrowest area of ​​the VTP, this increases bending and torsional loads. Consequently, the VTP structure is negatively impacted in terms of weight and cost.

[0026] Because the horizontal stabilizer fin (HTP) is attached to the top of the vertical stabilizer fin (VTP), the lateral load on the HTP is not adequately supported. Therefore, the fitting must bear a higher lateral load at the same point. This increases structural complexity and necessitates high-performance materials, which negatively impacts the structure's weight and cost.

[0027] Furthermore, due to the high position of the horizontal stabilizer (HTP), its maintenance is complex.

[0028] Cross-shaped tail

[0029] A middle ground between the conventional and T-tail configurations is found in the cruciform tail configuration. The horizontal stabilizer (HTP) intersects the vertical stabilizer (VTP) near the middle. It represents a compromise between the two configurations explained earlier.

[0030] In this configuration, the load from the horizontal stabilizer (HTP) is transferred to the vertical stabilizer (VTP). For reinforcement, a lower section of the vertical stabilizer (VTP) is required.

[0031] When installing the horizontal stabilizer (HTP), the load path of the vertical stabilizer (VTP) spars, longitudinal spars, and skin is interrupted. After the horizontal stabilizer (HTP) is installed, this load path is restored using several reinforcements.

[0032] The main disadvantage of the cruciform tail section is:

[0033] The lower section of the vertical tail fin (VTP) must be designed to be stiffer and more robust due to the high loads it bears. This increases its weight and cost.

[0034] Because the horizontal stabilizer fin (HTP) is attached at the midpoint of the vertical stabilizer fin (VTP), the lateral load on the HTP is not adequately supported. Consequently, the component must bear a higher lateral load at the same point. This increases structural complexity and necessitates high-performance materials, which negatively impacts the structure's weight and cost.

[0035] The vertical tail fin (VTP) is cut into two distinct sections by the horizontal tail fin (HTP). Several reinforcements are required to ensure that the load is transferred from the tip of the VTP to the root. Therefore, the overall weight and cost of the VTP increase.

[0036] In the case of a trunable horizontal stabilizer (HTP), the outer surface and internal structure of the vertical stabilizer (VTP) must be modified to position the trim actuator. Large holes in the VTP ribs are incorporated to avoid any interference with the connection to the helical jacks. This fact is detrimental to the overall weight of the VTP and increases the complexity of its design and maintenance. Summary of the Invention

[0037] The purpose of this invention is to provide a configuration for the tail section of an aircraft that improves the efficiency of the horizontal tail (HTP) without compromising the surrounding components (mainly the vertical tail (VTP) and the rear fuselage section).

[0038] The objective of the aircraft tail section of the present invention is a tail section having a horizontal stabilizer connected at the root of the vertical stabilizer.

[0039] The target of the tail section of the aircraft of the present invention includes:

[0040] - Vertical tail fin (VTP).

[0041] - Aft fuselage section. The aft fuselage section includes the skin and internal reinforcing members, which are the reinforcing members located on the skin side facing the center plane of the fuselage section. For example, frames and longitudinal beams. The vertical tail is attached to the aft fuselage section via an attachment assembly that extends from the internal reinforcing members to the vertical tail (VTP). Thus, a portion of the attachment assembly spans the skin of the aft fuselage section.

[0042] - Horizontal tail fin (HTP). The horizontal tail fin (HTP) can be truncate or fixed.

[0043] The horizontal stabilizer (HTP) includes:

[0044] - Two lateral anti-torsion boxes.

[0045] - A frame structure located between two lateral torsion boxes; the frame structure connects to the two lateral torsion boxes. The frame structure includes a front spar, a rear spar, and two ribs extending or spanning between the front and rear spars. Each rib is adjacent to a lateral torsion box, i.e., not far away or very far from it. Therefore, the frame structure is a parallelogram, i.e., it includes four sides. The frame structure is hollow and surrounds a portion of the vertical tail fin (VTP) along its wingspan. Thus, the frame structure of the horizontal tail fin (HTP) surrounds the longitudinal section of the vertical tail fin (VTP). The cross-section of the vertical tail fin (VTP) is surrounded or enclosed by a parallelogram formed by the two spars and the two ribs. In this way, the vertical tail fin (VTP) spans the horizontal tail fin (HTP), specifically through the opening formed by the frame structure.

[0046] As is well known, in a horizontal stabilizer (HTP), the spars extend along the wingspan to the HTP, and the ribs extend along the chord direction. Therefore, the front and rear spars of the frame structure are located in the wingspan direction of the HTP, and the two ribs are located in the chord direction of the HTP.

[0047] The tail section of the aircraft includes an attachment assembly that attaches the frame structure to the aft fuselage section. The attachment assembly extends between the internal reinforcing member of the aft fuselage section and the frame structure, thus spanning the skin of the aft fuselage section. In one embodiment, the attachment assembly may be attached to the frame of the aft fuselage section.

[0048] In one embodiment, the attachment assembly for attaching the frame structure to the rear fuselage section includes:

[0049] - A rear attachment that extends between the internal reinforcing member of the aft fuselage section and the aft wing spars of the frame structure and across the skin. For example, the rear attachment may protrude from the skin toward the frame structure of the aft fuselage section.

[0050] - The forward attachment extends between the internal reinforcing member of the aft fuselage section and the forward wing spars of the frame structure, and also crosses the skin.

[0051] One advantage of this invention is that, in embodiments, it allows the horizontal tail fin (HTP) to be positioned at the root region of the vertical tail fin (VTP) to allow both of the following:

[0052] - This ensures that the horizontal stabilizer (HTP) is completely outside the rear fuselage section.

[0053] - Avoid the influence of the horizontal tail (HTP) structure and load on the vertical tail (VTP).

[0054] The root region is the section of the vertical tail (VTP) closest to the rear fuselage. The end of the vertical tail (VTP) opposite the root is the tip.

[0055] The root region of the vertical tail covers up to 10% or 15% of the wingspan of the vertical tail (VTP) as measured from the skin of the rear fuselage section.

[0056] In this embodiment, the frame structure of the horizontal stabilizer is located near the skin of the aft fuselage section, relative to the vertical direction of the aircraft's tail section. "Near" means it is located not far from the skin. The distance between the two elements can vary from when they are in contact to when there is a gap between them.

[0057] The interfaces between the horizontal stabilizer (HTP) and vertical stabilizer (VTP) and the rear fuselage section are achieved through a frame structure to avoid any conflict between the two components.

[0058] Furthermore, the horizontal tail (HTP) and vertical tail (VTP) attachments to the aft fuselage section are located in a single area, thereby minimizing the structural reinforcements required and reducing overall weight and cost.

[0059] More specifically, the above technical features are defined as follows: horizontal tail (HTP) - vertical tail (VTP) - rear fuselage section interface.

[0060] Horizontal tail (HTP) - Aft fuselage section interface

[0061] The horizontal tail (HTP) structure includes two lateral torsion boxes, which are integrated into a frame structure located between the two lateral torsion boxes. This frame structure is connected to the aft fuselage section via attachment components.

[0062] In one embodiment, the horizontal stabilizer (HTP) may be truncate. The connection between the rear attachment of the attachment assembly and the frame structure is configured as a pivot of the truncate horizontal stabilizer, and the front attachment is configured to move the truncate horizontal stabilizer about the pivot to control the rotation angle of the horizontal stabilizer.

[0063] In one embodiment, the front attachment is a worm gear. In another embodiment, the rear attachment includes two lugs. The worm gear is connected to a truncate horizontal stabilizer actuator (THSA) to control the rotation angle.

[0064] Horizontal tail fin (HTP) - Vertical tail fin (VTP) interface

[0065] Once the horizontal stabilizer (HTP) is attached to the aft fuselage section, the vertical stabilizer (VTP) is housed within the frame structure. The VTP maintains the same interface design for attachment to aft fuselage sections known in the prior art.

[0066] In the case of a truncation horizontal stabilizer (HTP), because the HTP moves relative to the vertical stabilizer (VTP) and the rear fuselage, a standard clearance is maintained between the frame structure and the other two structures to avoid any interference.

[0067] In embodiments where the horizontal stabilizer (HTP) is trimmable and located in the root region of the vertical stabilizer (VTP), the distance between the horizontal stabilizer (HTP) in a straight position and the skin of the aft fuselage section is determined by the maximum trim angle of the horizontal stabilizer (HTP). This maximum angle defines the necessary distance from the skin based on the fixed point and the dimensions of the horizontal stabilizer (HTP).

[0068] Horizontal tail fin (HTP) frame structure

[0069] The horizontal tail (HTP) frame structure includes two spars (front and rear spars) and two ribs (left and right ribs).

[0070] In one embodiment, in order to attach the horizontal tail fin (HTP) side box to the frame structure, the front spar of the side box is connected to the front spar of the frame structure, and the rear spar of the side box is connected to the rear spar of the frame structure.

[0071] Compared to known solutions in the prior art, this invention achieves several advantages. Most importantly, it offers savings in drag, weight, and industrial costs, and also includes several configuration opportunities, detailed below:

[0072] Because the horizontal stabilizer (HTP) is located outside the rear fuselage section, its entire surface is wet. This makes it possible to have a smaller HTP with the same handling mass, thereby reducing drag, weight, and cost.

[0073] The configuration requiring protection offers better structural efficiency than cruciform and T-tail configurations. The horizontal stabilizer (HTP) structure and loads do not affect the vertical stabilizer (VTP). There is no need to stiffen the VTP to support loads from the horizontal stabilizer (FTP). There is no need to interrupt the VTP load path.

[0074] Because the horizontal stabilizer (HTP) is located outside the aft fuselage section, fuselage weight and cost are optimized due to improved structural efficiency (standard closed frame, no cutouts, etc.) and the removal of reinforcements from the cutout structure. Furthermore, the aft fuselage profile is not affected by the cutouts or their local hyperbolic curvature. Therefore, manufacturing and assembling the aft fuselage structure is relatively simple. Consequently, reducing the time and materials required on the production line is feasible.

[0075] Since the structural attachments for both the vertical tail (VTP) and horizontal tail (HTP) are confined to the same location, only the upper fuselage shell needs reinforcement. Therefore, it optimizes structural efficiency and achieves cost savings compared to other configurations, which require several localized reinforcements throughout the aft fuselage section due to different load introduction locations.

[0076] • Maintainability is similar to the conventional and cruciform tail configurations, and is even better than the T-tail configuration because the horizontal stabilizer (HTP) is located in the root region of the vertical stabilizer (VTP). This location is less susceptible to accidental damage than the conventional configuration due to its greater distance from the ground.

[0077] Because there is more usable space in the aft fuselage section, it can be used for various purposes, such as auxiliary power unit (APU) location, passenger boarding, and system allocation. This allows for a reduction in overall fuselage length, thereby lowering weight, cost, and drag.

[0078] Due to the required high rigidity and the use of a frame structure instead of a single center joint, there is an increase in weight associated with the horizontal tail (HTP) frame structure. Nevertheless, this weight loss is fully compensated or offset by the weight savings achieved by removing the rear fuselage cutout reinforcement and the overall reduction in the size of the horizontal tail (HTP), resulting in overall weight savings. Attached Figure Description

[0079] To complete the description and provide a better understanding of the invention, a set of accompanying drawings is provided. These drawings form an integral part of the specification and illustrate preferred embodiments of the invention. These drawings include the following figures.

[0080] Figure 1 A perspective view of the tail section of an aircraft, which is known in the prior art as a conventional tail, is shown.

[0081] Figure 2 A side view of the tail section of an aircraft, which is known in the prior art as a T-tail, is shown.

[0082] Figure 3 A side view of the tail section of an aircraft, which is known in the prior art as a cross-shaped tail, is shown.

[0083] Figure 4 A perspective view of the upper shell of the rear fuselage section is shown, which reveals the structural attachments of the vertical tail (VTP) and horizontal tail (HTP).

[0084] Figure 5 A perspective view of the tail section of an aircraft according to an embodiment of the present invention is shown.

[0085] Figure 6A schematic side view of an embodiment of the present invention is shown, illustrating the interface between the rear fuselage section, the vertical tail (VTP), and the horizontal tail (HTP).

[0086] Figure 7 A schematic plan view of the horizontal tail (HTP) and vertical tail (VTP) is shown.

[0087] Figure 8 A perspective view shows an embodiment of the frame structure, as well as the front and rear attachments of the rear fuselage section.

[0088] Figure 9 A schematic plan view of an embodiment of the frame structure with a front spar and a dorsal fin that covers the gap between the frame structure and the vertical tail fin (VTP) is shown. Detailed Implementation

[0089] Figure 1 A conventional tail section known in the prior art is disclosed. This tail section includes a vertical tail (VTP) (2) attached to the upper region of the aft fuselage section (1), and a horizontal tail (HTP) (3) spanning and attached to the internal structure of the aft fuselage section (1).

[0090] Figure 2 A T-tail configuration known in the prior art is disclosed. In this configuration, the horizontal tail fin (HTP)(3) is attached to the vertical tail fin above the vertical tail fin (VTP)(2).

[0091] Figure 3 A cross-shaped tail configuration known in the prior art is disclosed. In this configuration, the horizontal tail fin (HTP)(3) intersects with the vertical tail fin (VTP)(2) near the middle.

[0092] Figure 4 The upper shell of the aft fuselage section (1) is disclosed, showing the structural attachments of the vertical tail (VTP) (2). The aft fuselage section (1) includes a skin (1.1) and internal reinforcing members, particularly the frame (1.3). The attachments to the vertical tail (VTP) (2) include vertical tail attachments (1.2) that are integrated into the frame (1.3) and extend across the skin (1.1), thus projecting from the skin (1.1) toward the vertical tail (VTP) (2). The attachments shown include multiple pairs of lugs, each pair located between two consecutive frames (1.3).

[0093] Figure 4 An embodiment of attaching the frame structure (33) to the aft fuselage section (1) is also disclosed. The attachment assembly spans the skin (1.1) and extends between the frame (1.3) of the aft fuselage section (1) and the frame structure (33).

[0094] Figure 4 The attachment components shown include:

[0095] - The rear attachment (4), particularly the two lugs, extends between the frame (1.3) and the frame structure (33) of the rear fuselage section (1).

[0096] - The front attachment (5) extends between the frame (1.3) and the frame structure (33) of the rear fuselage section (1).

[0097] Figure 4 An attachment assembly further including a fitting (4.2) configured to bear the lateral loads of the horizontal stabilizer (HTP) (3) was also shown. The fitting (4.2) for bearing the lateral loads extends between two lugs of the rear attachment (4) and is aligned with the pivot (4.1).

[0098] Figure 5 A perspective view of an embodiment of the present invention is disclosed. The tail section of an aircraft is shown, in which:

[0099] - Rear fuselage section (1),

[0100] - The vertical tail fin (VTP) (2) attached to the rear fuselage section (1), and

[0101] - The horizontal tail (HTP) (3) is located at the root region of the vertical tail (2).

[0102] Figure 6 The rear fuselage section (1) is disclosed, which includes a vertical tail attachment (1.2) that protrudes from the skin (1.1) and is attached to the vertical tail (VTP) (2).

[0103] The vertical tail fin attachment (1.2) shown includes three lugs. Alternatively, instead of having several separate lugs, a continuous attachment can be implemented.

[0104] It also shows that the horizontal stabilizer (HTP) (3) is located below the vertical stabilizer (VTP) (2), that is, it is located near the skin (1.1) of the rear fuselage section (1) at the root region of the vertical stabilizer (VTP) (2). The horizontal stabilizer (HTP) (3) is trimmable.

[0105] Figure 6 It also shows:

[0106] -Attached connector (4), and

[0107] - Front attachment (5).

[0108] Figure 7Embodiments of the present invention are disclosed, showing a truncation-compatible horizontal stabilizer (HTP) (3), the truncation-compatible horizontal stabilizer comprising:

[0109] - Two lateral torsion boxes (31, 32).

[0110] - A frame structure (33) is located between the two lateral torsion boxes (31, 32). The frame structure (33) is connected to the two lateral torsion boxes (31, 32). The frame structure (33) includes a front spar (34), a rear spar (35), and two ribs (36, 37). Each rib (36, 37) is located near the lateral torsion boxes (31, 32). Furthermore, the frame structure (33) surrounds the cross-section of the vertical tail fin (VTP)(2) such that the longitudinal portion of the vertical tail fin (VTP)(2) is surrounded by the frame structure (33).

[0111] The aft attachment (4) is attached to the rear wing spars (35) of the frame structure (33). The aft attachment (4) is also attached to the rear fuselage section (1), such as... Figure 6 As shown. The junction of the rear attachment (4) and the rear wing spars (35) is configured as a pivot (4.1) of the jacking horizontal tail fin (HTP) (3), as shown. Figure 6 As shown in the image.

[0112] Figure 7 A plan view of a fitting (4.2) for bearing the lateral loads of the horizontal stabilizer (HTP) (3) is also disclosed, which extends between the two lugs of the rear attachment (4) and is aligned with the pivot (4.1). For clarity, Figure 8 The aforementioned accessory (4.2) is not shown in order to better show the rear wing spars (35).

[0113] The forward attachment (5) is connected to the forward wing spars (34) of the frame structure (33). The forward attachment (5) is also connected to the aft fuselage section (1), such as Figure 6 As shown in the diagram. The front attachment (5) is configured to move the pliable horizontal tail fin (HTP) (3) about a pivot (4.1) to control the rotation angle of the horizontal tail fin (HTP) (3).

[0114] exist Figure 6 In the embodiment shown, the front attachment (5) includes a worm gear. Furthermore, the front attachment (5) includes an actuator (6) and a trimmable horizontal stabilizer actuator (THSA) configured to control the rotation angle of the horizontal tail fin (HTP) (3). The actuator (6) is connected to the worm gear. The worm gear is attached to the front attachment (5).

[0115] In the illustrated embodiment, the actuator (6) is placed within the rear fuselage section (1), specifically on the skin side facing the midplane of the fuselage section. For this purpose, the skin (1.1) of the rear fuselage section (1) includes an opening to allow the worm gear to pass through the skin.

[0116] Furthermore, since the trimable horizontal stabilizer actuator (THSA) (6) is kept within the rear fuselage section (1), the vertical tail (VTP) (2) design is not affected by the trim actuation of the horizontal tail (HTP) (3), just as in the case of T-tail and cross-tail configurations where the internal structure of the vertical tail (VTP) (2) is impacted.

[0117] In the illustrated embodiment, the rear attachment (4) includes lugs, specifically two lugs. Each lug is attached to the rear wing spar (35). Furthermore, the two lugs are positioned aligned longitudinally with the frame structure ribs (36, 37) to minimize the load effect on the rear wing spar (35). The attachment of these lugs to the frame structure (33) is implemented by bolts.

[0118] The front attachment (5) is positioned near the longitudinal center of the front spar (34) to minimize momentum by reducing the distance to the worm. More specifically, as Figure 8 As shown, the front attachment (5) includes two fittings (55).

[0119] In the truncation horizontal stabilizer (HTP)(3), because the horizontal stabilizer (HTP)(3) moves relative to the vertical stabilizer (VTP)(2) and the rear fuselage section (1), a standard clearance is maintained between the frame structure (33) and the other two structures to avoid any collisions, such as Figure 6 and Figure 7 As shown in the image.

[0120] As previously described, the frame structure (33) includes two spars (front spar (34) and rear spar (35)) and two ribs (left rib (36) and right rib (37)). To attach the horizontal stabilizer (HTP) (3) side box to the frame structure (33), the front spar (31.1, 32.1) and rear spar (31.2, 32.2) of the horizontal stabilizer (HTP) (2) side box (31, 32) are respectively attached to the front spar (34) and rear spar (35) of the frame structure (33). Specifically, a single lap shear joint is used.

[0121] Furthermore, an additional high-load frame will be required on top of the high-load frame (1.3) defined in the aft fuselage section (1) to attach the vertical tail (VTP) (2) in order to bear the load from the aft support fittings. This additional high-load frame can be an intermediate frame or a closed aft fuselage frame as in a conventional tail configuration.

[0122] In the case of horizontal tail fin (HTP)(2) side covers, these side covers can be connected to the frame structure (33) through different structural schemes (such as a single shear joint or a tension joint).

[0123] Figure 5 and Figure 6 A horizontal tail (HTP) (3) is shown in the root region of the vertical tail (VTP) (2). The vertical tail (VTP) (2) includes a rudder (2.1). In the illustrated embodiment, the rudder (2.1) includes a lower edge (2.2) located near the rear attachment (4) of the horizontal tail (HTP) (3) relative to the vertical direction of the aircraft tail section.

[0124] In an alternative embodiment, the horizontal tail fin (HTP) (3) may be located above the vertical tail fin (VTP) (2).

[0125] Since the horizontal tail (HTP) (3) frame structure (33) is rectangular in shape and the load points from the horizontal tail (HTP) (3) are located at the edge of the frame structure (33), it is necessary to strengthen the frame structure (33) in order to withstand the momentum generated by these loads.

[0126] Since the internal area of ​​the frame structure (33) is used to distribute the vertical tail fin (VTP) (2), the frame structure (33) is reinforced by corner fittings to ensure that it does not conflict with the structure around the vertical tail fin (VTP) (2).

[0127] The corner fittings and lugs allow these components to be attached to the rear wing beam of the frame (35) using the same bolts.

[0128] Two possibilities are depicted for manufacturing the frame structure (33). The entire frame structure (33) can be mechanized using high-performance metals. The frame structure (33) can be manufactured as a single piece. Another possibility is to have composite spars (34, 35) and ribs (36, 37) as well as metal corner fittings to join these elements together. In embodiments, the frame structure (33) can be manufactured together with one of the lateral torsion boxes (31, 32), or even the lateral torsion boxes (31, 32) and the frame structure (33) can be manufactured as a single component.

[0129] The frame structure (33) can be covered by a fairing.

[0130] To allow for the placement of the horizontal tail (HTP)(3) and the frame structure (33), the front and rear fairings of the vertical tail (VTP)(2) must have cutouts at which the frame structure (33) spans their surfaces. These cutouts must be large enough to allow the horizontal tail (HTP)(3) to rotate, for example, +1° upward and +15° downward.

[0131] In addition, the tail section includes, for example Figure 9 The dorsal fin (60) is shown in the diagram. The dorsal fin (60) closes the gap between the frame structure (33) and the vertical tail fin (VTP) (2) to minimize aerodynamic drag. The surface of the dorsal fin (60) includes at least two flat sections, one on the port side and one on the starboard side, in which the horizontal tail fin (HTP) (3) fairing contacts the dorsal fin (60) to allow the HTP (3) to move up and down.

Claims

1. A tail section of an aircraft, comprising: Vertical tail fin (2). The rear fuselage section (1) includes a skin (1.1) and internal reinforcing members, and the vertical tail (2) is attached to the rear fuselage section (1). The horizontal tail fin (3) includes two lateral anti-torsion boxes (31, 32). The horizontal tail fin (3) is characterized in that it further comprises: A frame structure (33) is located between and connected to the two lateral torsion boxes (31, 32). The frame structure (33) includes a front spar (34), a rear spar (35), and two ribs (36, 37) extending between the front spar (34) and the rear spar (35), each rib (36, 37) being adjacent to the lateral torsion box (31, 32). The frame structure (33) surrounds a portion of the vertical tail fin (2) along its wingspan. The tail section of the aircraft includes an attachment assembly that attaches the frame structure (33) to the rear fuselage section (1), the attachment assembly spanning the skin (1.1) and extending between the internal reinforcing member of the rear fuselage section (1) and the frame structure (33).

2. The tail section of the aircraft according to claim 1, wherein, The attachment assembly for attaching the frame structure (33) to the rear fuselage section (1) includes: A rear attachment (4) extends between the internal reinforcing member of the rear fuselage section (1) and the rear wing spars (35) of the frame structure (33). The front attachment (5) extends between the internal reinforcing member of the rear fuselage section (1) and the front wing spars (34) of the frame structure (33).

3. The tail section of the aircraft according to claim 2, wherein, The horizontal tail fin (3) is truncate, the connection between the rear attachment (4) and the frame structure (33) is configured as a pivot (4.1) of the truncate horizontal tail fin (3), and the front attachment (5) is configured to move the truncate horizontal tail fin (3) about the pivot (4.1) to control the rotation angle of the horizontal tail fin (3).

4. The tail section of the aircraft according to claim 3, wherein, The front attachment (5) includes a worm gear.

5. The tail section of the aircraft according to claim 4, wherein, The front attachment (5) includes an actuator (6) connected to the worm gear and configured to move the pliable horizontal tail fin (3) about the pivot (4.1) to control the rotation angle of the horizontal tail fin (3).

6. The tail section of the aircraft according to claim 5, wherein, The actuator (6) is placed inside the rear fuselage section (1).

7. The aircraft tail section according to claim 6, wherein, The skin (1.1) of the rear fuselage section (1) includes an opening that allows the worm gear to pass through.

8. The tail section of an aircraft according to any one of claims 1 to 7, wherein, The frame structure (33) is located at the root region of the vertical tail fin (2).

9. The tail section of an aircraft according to claim 8, wherein, The frame structure (33) of the horizontal tail (3) is located near the skin (1.1) of the rear fuselage section (1) in the wingspan direction relative to the vertical tail (2).

10. The aircraft tail section according to any one of claims 1 to 7, wherein, The vertical tail fin (2) includes a rudder (2.1) with a lower edge (2.2) located near the rear attachment (4) of the horizontal tail fin (3) in the wingspan direction of the vertical tail fin (2).

11. The tail section of an aircraft according to any one of claims 1 to 7, wherein, The two lateral torsion boxes (31, 32) include a front wing beam (31.1, 32.1) and a rear wing beam (31.2, 32.2), the front wing beam (34) of the frame structure (33) is connected to the front wing beam (31.1, 32.1) of the lateral torsion box (31, 32), and the rear wing beam (35) of the frame structure (33) is connected to the rear wing beam (31.2, 32.2) of the lateral torsion box (31, 32).

12. The aircraft tail section according to any one of claims 2 to 7, wherein, The front attachment (5) is attached to the frame structure (33) near the longitudinal center of the front wing beam (34).

13. The aircraft tail section according to any one of claims 2 to 7, wherein, The rear attachment (4) includes two lugs, each lug engaging with the rear wing beam (35) of the frame structure (33) and aligned longitudinally with each rib (36, 37).

14. The tail section of an aircraft according to any one of claims 1 to 7, wherein, The wing beams (34, 35) and ribs (36, 37) of the frame structure (33) are metal.

15. The tail section of an aircraft according to any one of claims 1 to 7, wherein, The spars (34, 35) and the ribs (36, 37) are made of composite materials.

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