CFRP fuselage frame fixed to vertical tail fin

Abstract

To meet the need to reduce aircraft production costs related to corrosion protection measures being taken with use of different materials such as aluminum for frames and CFRP for the outer skin of an aircraft, and to reduce thermal fatigue resulting from thermal expansion effects on interconnected structures in an aircraft that are constructed of different materials having different thermal expansion coefficients respectively, and to meet the need to shorten production time with respect to the time imparted to production using metallic frames.SOLUTION: A fixing assembly for fixing a vertical tail fin assembly to an aircraft includes a first lug member which is fixed to the vertical tail fin assembly. The fixing assembly further includes a first U-shaped clevis member. In the first U-shaped clevis member, a first end of the first U-shaped clevis member is engaged with the first lug member. A second end of the first U-shaped clevis member is fixed to a first fuselage frame constructed of a composite material, with a first fastener extending through the second end and the first fuselage frame in a first direction crossing the first fuselage frame.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to fastening an aerospace vehicle vertical fin assembly to an aerospace vehicle, and more particularly to fastening a vertical fin assembly to an aircraft fuselage frame. [Background technology]

[0002] Corrosion is a concern for aluminum fuselage frames, where the aluminum frame is attached to an aircraft's composite fiber-reinforced polymer ("CFRP") skin. Furthermore, constructing an aircraft using, for example, an aluminum frame with a CFRP skin creates fatigue issues due to differences in the materials and their differing thermal expansion effects. For example, aluminum has a thermal expansion coefficient greater than that of CFRP. Aluminum contracts at low temperatures and expands at high temperatures, relative to the relatively thermally neutral CFRP material. As a result of using different materials for the frame structure and the skin structure, these structures are subjected to different temperatures during aircraft operation, resulting in compressive and tensile forces. Furthermore, with regard to manufacturing, metal frames, such as aluminum fuselage frames, require deburring after drilling to prevent fatigue cracking and joint sealing before installation to prevent corrosion, resulting in increased manufacturing time demands. Summary of the Invention [Problem to be solved by the invention]

[0003] As a result, there is a need to reduce the costs of aircraft manufacturing associated with corrosion protection measures implemented using different materials, such as aluminum for the frame and CFRP for the aircraft skin, reduce thermal fatigue as a result of thermal expansion effects on interconnecting structures within the aircraft constructed of different materials, each with different thermal expansion coefficients, and reduce manufacturing time relative to the time provided for manufacturing using metal frames. [Means for solving the problem]

[0004] One example includes a fastening assembly for fastening a vertical fin assembly to an aircraft, the fastening assembly including a first lug member fastened to the vertical fin assembly, a first U-shaped hook member, a first end of the first U-shaped hook member engaging the first lug member, and a second end of the first U-shaped hook member fastened to a first fuselage frame constructed of composite material with a first fastener extending through the second end and the first fuselage frame in a first direction across the first fuselage frame.

[0005] One example includes a method for securing a vertical fin assembly to an aircraft, the method including securing a first lug member secured to the vertical fin assembly to a first end of a first U-shaped hook member, the method further including securing the second end of the first U-shaped hook member to a first fuselage frame constructed of composite material with a first fastener extending through the second end of the first U-shaped hook member and the first fuselage frame in a first direction across the first fuselage frame.

[0006] The described features, functions, and advantages can be achieved independently in various embodiments or can be combined in yet further embodiments, further details of which can be seen with reference to the following description and drawings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of an aircraft. [Figure 2] 2 is a partial perspective view, looking toward the front of the aircraft of FIG. 1, of a composite fuselage frame secured to a portion of the aircraft vertical tail assembly, without the composite fuselage skin shown. [Figure 3] 3 is a partial perspective view of a composite fuselage frame secured to a portion of the aircraft vertical tail assembly of FIG. 2, looking toward the rear of the aircraft of FIG. 1. FIG. [Figure 4] 3 is a partial end view, looking toward the front of the aircraft of FIG. 1, of a composite fuselage frame secured to a portion of the aircraft vertical tail assembly of FIG. 2. [Figure 5] FIG. 3 is a top partial plan view of the two composite fuselage frames of FIG. 2, each having two U-shaped hook members spaced apart from one another along each of the two composite fuselage frames, without the presence of either a vertical tail assembly or lug members. [Figure 6] 6 is a cross-sectional view taken along line 6-6 as seen in FIG. 5, including a lug member secured to a U-shaped hook member extending through a composite fuselage skin. [Figure 7] 7 is a cross-sectional view taken along line 7-7 shown in FIG. 5, including a lug member secured to a U-shaped hook member. [Figure 8] 8 is a schematic diagram of fiber arrangement within a composite material of a fuselage frame, as typically seen at the circle identified in FIG. 4 as "See FIG. 8." [Figure 9] 2 is a schematic cross-sectional view of the aircraft fuselage and vertical tail fin assembly of FIG. 1 illustrating the reaction forces experienced by a fastening assembly that applies a lateral force to the vertical tail fin assembly and secures the fuselage frame to the aircraft vertical tail fin assembly. [Figure 10] 1 is a flowchart of a method for securing a vertical tail fin assembly to an aircraft. DETAILED DESCRIPTION OF THE INVENTION

[0008] Referring to FIG. 1 , an aircraft 10 includes a fuselage assembly 12, a wing assembly 14, and a vertical tail fin assembly 16. During the manufacture of the aircraft 10, the vertical tail fin assembly 16 includes a spar and rib support structure (not shown) to which an outer skin 18 of the aircraft 10 is secured. The vertical tail fin assembly 16 is further secured to the fuselage assembly 12 of the aircraft 10 while connected to a fuselage frame. In the construction of the aircraft 10, as previously described, manufacturers have utilized metals such as aluminum to construct the fuselage frame. The metal fuselage frame has been similar in configuration to fuselage frames, such as first, second, third, and fourth fuselage frames 20a, 20b, 20c, and 20d, as seen in FIGS. 2-4 . The number of fuselage frames to which the vertical tail fin assembly 16 is secured may vary depending on the design of the particular aircraft 10.

[0009] In the present disclosure, the first through fourth fuselage frames 20a-20d are constructed of CFRP material instead of metal, thereby avoiding the drawbacks previously described with respect to metal fuselage frames. By utilizing CFRP to construct the fuselage frames, corrosion resistance precautions are no longer required for metal fuselage frames. Additionally, with fuselage frames constructed of CFRP, there is no longer a need for material fatigue-related inspections for the first through fourth fuselage frames 20a-20d and the fuselage skin 22. Both the first through fourth fuselage frames 20a-20d and the skin 18 of the aircraft 10 are constructed of similar CFRP material, and as a result, the first through fourth fuselage frames 20a-20d and the skin 18 have similar thermal expansion coefficient characteristics. Furthermore, the extended production time for the aircraft 10 is reduced by eliminating the forging sequence delay associated with the manufacture of the metal fuselage frames, which is removed from the production schedule.

[0010] These drawbacks are overcome in this example by the first through fourth fuselage frames 20a-20d and fuselage skin 22, both of which are constructed of CFRP material. Due to the advantages provided by the use of CFRP material for fuselage frames such as 20a-20d, a fastening assembly 24, as discussed herein, is required to fasten the vertical tail fin assembly 16 to the aircraft 10 via the first through fourth fuselage frames 20a-20d of the fuselage assembly 12. The fastening assembly 24 provides the necessary transfer of shear loads from the vertical tail fin assembly 16 to the first through fourth fuselage frames 20a-20d of this example, which are constructed of CFRP material.

[0011] The fastening of the vertical tail fin assembly 16 to the fuselage frame, which is constructed of metal, was achieved by bolting the vertical tail fin assembly 16 in a generally perpendicular orientation relative to the vertical tail fin assembly 16 and the metal fuselage frame. However, this fastening configuration does not provide optimal shear resistance to shear loads transferred from the vertical tail fin assembly 16 to the first through fourth fuselage frames 20a-20d, which are constructed of CFRP material, in this example, as a result of movement of the aircraft 10. As a result, the fastening assemblies 24, as seen in Figures 2-7 and described herein, optimally fasten the vertical tail fin assembly 16 to the first through fourth fuselage frames 20a-20d, which are constructed of CFRP, in this example, for resistance to shear loads resulting from the vertical tail fin assembly 16.

[0012] In this example of securing the vertical tail fin assembly 16 to four first through fourth fuselage frames 20a-20d herein, each of the first through fourth fuselage frames 20a-20d has a pair of spaced-apart fastening assemblies 24 that secure the vertical tail fin assembly 16 to the first through fourth fuselage frames 20a-20d, respectively. Referring to Figure 2, a perspective view of the first through fourth fuselage frames 20a-20d on a starboard side 26 of the aircraft 10 is seen, and Figure 3 shows a perspective view of the first through fourth fuselage frames 20a-20d on a port side 28 of the aircraft 10. These two figures provide a view of each pair of fastening assemblies 24 for each of the first through fourth fuselage frames 20a-20d. A first pair 30 of fastening assemblies 24 is disposed on the first fuselage frame 20a, a second pair 32 of fastening assemblies 24 is disposed on the second fuselage frame 20b, a third pair 34 of fastening assemblies 24 is disposed on the third fuselage frame 20c, and a fourth pair 36 of fastening assemblies 24 is disposed on the fourth fuselage frame 20d.

[0013] In this example, the first pair 30 and the fourth pair 36 of the fastening assemblies 24 are similarly configured and are optimally suited to resist shear forces transmitted from the vertical tail fin assembly 16, with the resulting shear loads directed in a forward direction 38 and an aft direction 40, as seen in Figures 2 and 3. In contrast, in this example, the second pair 32 and the third pair 34 of the fastening assemblies 24 are similarly configured and are optimally suited to resist shear forces transmitted from the vertical tail fin assembly 16, with the resulting shear loads directed in either a starboard direction 42 or a port direction 44. The difference between the first pair 30 and the fourth pair 36 of the fastening assemblies 24, on the one hand, and the second pair 32 and the third pair 34 of the fastening assemblies 24, on the other hand, is the orientation of the pins used in the fastening assemblies 24 to the lug members, which will be discussed. In the first pair 30 and the fourth pair 36 of fastener assemblies 24, the pins for each fastener assembly 24 are positioned to extend along the first fuselage frame 20a and the fourth fuselage frame 20d, respectively. In the second pair 32 and the third pair 34 of fastener assemblies 24, the pins for each fastener assembly 24 are positioned to extend across the second fuselage frame 20b and the third fuselage frame 20c, respectively.

[0014] 2 and 3, the first pair 30 of fastening assemblies 24 is disposed on the first fuselage frame 20a, and the second pair 32 of fastening assemblies 24 is disposed on the second fuselage frame 20b. It should be understood that the location of the first fuselage frame 20a supporting the first pair 30 of fastening assemblies 24 is not limited to being disposed at the aft-most position 48 of the first through fourth fuselage frames 20a through 20d fixed to the vertical tail fin assembly 16, and that the location of the fourth fuselage frame 20d supporting the fourth pair 36 of fastening assemblies 24 is not limited to being disposed at the forward-most position 50 of the first through fourth fuselage frames 20a through 20d fixed to the vertical tail fin assembly 16. Similarly, the second pair 32 of fastening assemblies 24 is not limited to being disposed on the second fuselage frame 20b disposed between the first pair 30 and the fourth pair 36 of fastening assemblies 24, which are disposed on the first fuselage frame 20a and the fourth fuselage frame 20d, respectively. Similarly, the third pair 34 of fastening assemblies 24 is not limited to being disposed on the third fuselage frame 20c disposed between the first pair 30 and the fourth pair 36 of fastening assemblies 24, which are disposed on the first fuselage frame 20a and the fourth fuselage frame 20d, respectively. In the present example described herein, the first pair 30 and the fourth pair 36 of fastening assemblies 24 are disposed on the first fuselage frame 20a and the fourth fuselage frame 20d, which are disposed at the aft-most position 48 and the forward-most position 50 of the aircraft 10, respectively, for fastening to the vertical tail fin assembly 16. The second pair 32 and the third pair 34 are disposed on the second fuselage frame 20b and the third fuselage frame 20c, respectively, which are disposed between the first fuselage frame 20a and the fourth fuselage frame 20d, for securing the vertical tail fin assembly 16.

[0015] 2-7, the fastening assembly 24 for fastening the vertical tail fin assembly 16 to the aircraft 10 by fastening to the first through fourth fuselage frames 20a-20d in this example includes a first lug member 46 that is fastened (not shown) to the vertical tail fin assembly 16, for example, by bolting the first lug member 46 (not shown) to a framework of spars and ribs (not shown) of the vertical tail fin assembly 16. A first U-shaped hook member 52 disposed on the first fuselage frame 20a has a first end 54 of the first U-shaped hook member 52 that engages with the first lug member 46, as seen in FIG. 6, which will be described in further detail. The first U-shaped hook member 52 further includes a second end 56 of the first U-shaped hook member 52 that is fastened to the first fuselage frame 20a constructed of a composite material, CFRP. The first fasteners 58 extend through the second end 56 and the first fuselage frame 20a in a first direction 60 across the first fuselage frame 20a, as will be further described. In this example, the first fasteners 58 include bolt and nut assemblies.

[0016] 6 , the first U-shaped hook member 52 has a first prong 62 that defines a first opening 64 at the first end 54 of the first U-shaped hook member 52 and a second prong 66 that defines a second opening 68 at the first end 54 of the first U-shaped hook member 52. The first lug member 46 is disposed between the first prong 62 and the second prong 66 of the first U-shaped hook member 52. The first pin 70 extends through a first lug opening 72 defined by and extending through the first lug member 46 that engages the first U-shaped hook member 52 with the first lug member 46, passing through the first opening 64 of the first prong 62, the second opening 68 of the second prong 66, and the first pin 70 extending in a first direction 60 across the first fuselage frame 20a. The second end 56 of the first U-shaped hook member 52 includes a first locking flange 74 that extends along a forward side 76 of the first fuselage frame 20a with a first fastener 58 extending through the first locking flange 74 and the first fuselage frame 20a. As can be seen in Figures 4 and 6, by arranging the first fastener 58 extending in a first direction 60 across the first fuselage frame 20a, the first U-shaped hook member 52 is fixed to the first fuselage frame 20a constructed of CFRP, and the first fixing flange 74 is optimally fixed to the first fuselage frame 20a to optimally resist the shear load received from the vertical tail fin assembly 16.

[0017] 5, the first pair of U-shaped hook members 35 includes a first U-shaped hook member 52 and a second U-shaped hook member 78 fixed to the first fuselage frame 20a, the first U-shaped hook member 52 and the second U-shaped hook member 78 being spaced apart from each other in a second direction 80 along the first fuselage frame 20a. The first U-shaped hook member 52 has a first prong 62 that defines a first opening 64 at a first end 54 of the first U-shaped hook member 52, and the second U-shaped hook member 78 has a first prong 82 that defines a first opening 84 at a first end 89 of the second U-shaped hook member 78, similar to the first end 54 of the first U-shaped hook member 52, as seen in FIG. The first U-shaped hook member 52 has a second prong 66 defining a second opening 68 at a first end 54 of the first U-shaped hook member 52, and the second U-shaped hook member 78 has a second prong 86 defining a second opening 88 at a first end 89 shown in FIG. 4 of the second U-shaped hook member 78, which is similar to the first end 54 of the first U-shaped hook member 52, as seen in FIG. 6, as seen in FIG. 5.

[0018] The first lug member 46 is disposed between the first prong 62 and the second prong 66 of the first U-shaped hook member 52 of the first pair 35 of the first U-shaped hook member 52 and the second U-shaped hook member 78, as seen in FIG. 4. The second lug member 90 is disposed between the first prong 82 and the second prong 86 of FIG. 5 of the second U-shaped hook member 78 of the first pair 35 of the first U-shaped hook member 52 and the second U-shaped hook member 78, as seen in FIG. The first pin 70 extends through a first opening 64 in the first prong 62 of the first U-shaped hook member 52, a second opening 68 in the second prong 66 of the first U-shaped hook member 52, and through a first lug opening 72 defined by and extending through the first lug member 46 such that the first pin 70 extends in a first direction 60 across the first fuselage frame 20a, as seen in FIG. A second pin (not shown) extends through a first opening 84 in a first prong 82 of the second U-shaped hook member 78, a second opening 88 in a second prong 86 of the second U-shaped hook member 78, and a second lug opening (not shown) defined by and extending through a second lug member 90 such that the second pin (not shown) extends in a first direction 60 across the first fuselage frame 20a, as seen in Figure 4. The configuration of the second U-shaped hook member 78 engaged with the second lug member 90 is similar to that shown in Figure 6 for the first U-shaped hook member 52 secured to the first lug member 46.

[0019] The second end 56 of the first U-shaped hook member 52 includes a first locking flange 74, as seen in Figure 6, and the second end 91 of the second U-shaped hook member 78 includes a second locking flange 92, as seen in Figure 4. The first locking flange 74 extends along a forward side 76 of the first fuselage frame 20a, with first fasteners 58, Figure 6, extending through the first locking flange 74 and the first fuselage frame 20a in a first direction 60 across the first fuselage frame 20a. The second fixing flange 92 extends along the forward side 76 of the first fuselage frame 20a, as seen in FIG. 4, with second fasteners 94 extending through the second fixing flange 92 and the first fuselage frame 20a in the first direction 60 across the first fuselage frame 20a, similar to the configuration of the first fixing flange 74 seen in FIG. 6.

[0020] 5 and 7 , the third U-shaped hook member 96 is fixed to a second fuselage frame 20b, in this example constructed of composite carbon fiber reinforced plastic (CFRP), spaced from the first U-shaped hook member 52 along the length L of the aircraft 10, and has a first prong 98 that defines a first opening 100 at a first end 102 of the third U-shaped hook member 96, and a second prong 104 that defines a second opening 106 at the first end 102 of the third U-shaped hook member 96. A third lug member 108 is disposed between the first prong 98 and the second prong 104 of the third U-shaped hook member 96. The third pin 110 passes through the first opening 100 in the first prong 98 of the third U-shaped hook member 96, the second opening 106 in the second prong 104, and extends through a third lug opening (not shown) defined by and extending through the third lug member 108 engaging the third U-shaped hook member 96 with the third lug member 108 such that the third pin 110 extends in a third direction 112 along the second fuselage frame 20b, as seen in FIG. 5 . As seen in FIG. 7 , the second end 114 of the third U-shaped hook member 96 includes a third fixing flange 116 extending along a forward side 118 of the second fuselage frame 20b with a third fastener 120, such as a bolt with a nut, extending through the third fixing flange 116 and the second fuselage frame 20b in a fourth direction 122 transverse to the second fuselage frame 20b.

[0021] 5, this example further includes a second pair of U-shaped hook members 37 including a third U-shaped hook member 96 as described above and a fourth U-shaped hook member 124 fixed to a second fuselage frame 20b, also constructed of a carbon fiber reinforced plastic (CFRP) composite material. The third U-shaped hook member 96 and the fourth U-shaped hook member 124 are spaced apart from each other in a third direction 112 along the second fuselage frame 20b. As described above, the third U-shaped hook member 96 has a first prong 98 that defines a first opening 100 at a first end 102 of the third U-shaped hook member 96, and the fourth U-shaped hook member 124 has a first prong 126 that defines a first opening 127 at a first end (not shown) of the fourth U-shaped hook member 124. A first end (not shown) of the fourth U-shaped hook member 124 is similar to the first end 102 of the third U-shaped hook member 96 shown in Figure 7. The third U-shaped hook member 96 seen in Figure 5 above has a second prong 104 that defines a second opening 106 at the first end 102 of the third U-shaped hook member 96. The fourth U-shaped hook member 124 has a second prong 128 that defines a second opening 130 at the first end (not shown) of the fourth U-shaped hook member 124.

[0022] The third lug member 108 is disposed between the first prong 98 and the second prong 104 of the third U-shaped hook member 96. The fourth lug member 132 is disposed between the first prong 126 and the second prong 128 of the fourth U-shaped hook member 124 of FIG. 5, as seen in FIG. 3. The third pin 110 passes through the first opening 100 of the first prong 98 of the third U-shaped hook member 96, the second opening 106 of the second prong 104 of the third U-shaped hook member 96, as seen in FIG. 7, and extends through a third lug opening (not shown) defined by and extending through the third lug member 108 such that the third pin 110 extends in a third direction 112 along the second fuselage frame 20b, as shown in FIG. 5. A fourth pin (not shown), similar to the third pin 110 seen in FIG. 7, extends through a first opening 127 in the first prong 126 of the fourth U-shaped hook member 124 of FIG. 5, a second opening 130 in the second prong 128 of the fourth U-shaped hook member 124, and a fourth lug opening (not shown) defined by and extending through the fourth lug member 132, as seen in FIG. 3, such that the fourth pin (not shown) extends in the third direction 112 along the second fuselage frame 20b, as seen in FIG. 5.

[0023] The second end 114 of the third U-shaped hook member 96 includes a third fixing flange 116, as seen in FIG. 7, and the second end (not shown) of the fourth U-shaped hook member 124 includes a fourth fixing flange 134, as seen in FIG. 2. The second end (not shown) and fourth fixing flange 134 of the fourth U-shaped hook member 124 are similar to the second end 114 and third fixing flange 116 of the third U-shaped hook member 96, as shown in FIG. 7. The third fixing flange 116 extends along a forward side 118 of the second fuselage frame 20b with a third fastener 120, as seen in FIGS. 2 and 7, that extends through the third fixing flange 116 and the second fuselage frame 20b in a fourth direction 122 transverse to the second fuselage frame 20b. The fourth fixing flange 134 extends along the forward side 118 of the second fuselage frame 20b with a fourth fastener (not shown) as seen in FIG. 2, similar to the fastening arrangement of the third fixing flange 116 seen in FIG. 7, which extends through the fourth fixing flange 134 and the second fuselage frame 20b in a fourth direction 122 across the second fuselage frame 20b, similar to the third fastener 120 of FIG. 7.

[0024] The first through fourth fuselage frames 20a through 20d are constructed of a composite material, such as CFRP, in this example. In this example, the composite material has a five-ply configuration for each layer of composite material used in constructing the first through fourth fuselage frames 20a through 20d, and in this example, multiple layers of composite material are used. Referring to FIG. 8 , one ply has a nonlinear fiber configuration 136 of fibers. In constructing each layer of composite material, one ply of composite material includes a nonlinear fiber configuration 136 of fibers that comprises 20% of the plies in that layer. In this example, the nonlinear fiber configuration 136 of fibers extends in a curved direction having a radial axis R. Two plies of composite material have a first linear fiber configuration of fibers 138 that extend within an angular range including plus or minus 5 degrees of plus or minus 30 degrees angularly displaced from the radial axis R. The angular displacement is represented as an angle "A." Two plies of composite material have a first linear fiber configuration of fibers 138 that comprises approximately 40% of the plies in that layer. The other two plies of composite material for the layer include a second straight fiber configuration of fibers 140 extending within an angular range including minus 30 degrees plus or minus 5 degrees angularly displaced from the radial axis R. The angular displacement is represented as angle "B." This example fiber configuration in composite material provides a construction that is lighter than a metal counterpart fuselage frame and provides the necessary resistance to shear loads resulting from the vertical tail fin assembly 16 as a result of the movement of the aircraft 10.

[0025] Referring to FIG. 9 , a schematic cross-sectional view of the aircraft 10, as viewed toward a position 48 aft of the aircraft 10, is shown, along with the fuselage assembly 12 and vertical tail fin assembly 16. An example of reactive shear forces on the first through fourth fuselage frames 20a-20d during operation of the aircraft 10 is illustrated. In operation of the aircraft 10, as in this example, an aerodynamic operating force F can be applied from the starboard side 26 of the aircraft 10. The resultant load of the aerodynamic operating force F is transferred through the vertical tail fin assembly 16, such that the fuselage frames 20a-20d, in opposing the aerodynamic operating force F, provide a reaction force of a force F1 directed toward the vertical tail fin assembly 16 on the port side 28 of the vertical tail fin assembly 16 of the aircraft 10 and a force F2 directed away from the vertical tail fin assembly 16 on the starboard side 26 of the vertical tail fin assembly 16 of the aircraft 10. When the direction of the aerodynamic operating force F is reversed, the directions of the reaction forces F1 and F2 are reversed. In the example of the fastener assemblies 24 described herein, the second pair 32 and the third pair 34 of fastener assemblies 24 located on the fuselage frames 20b and 20c, respectively, provide optimal load transfer between the fuselage frames 20b and 20c when dealing with the aerodynamic operating force F from the starboard side 26 or the port side 28 of the aircraft 10. The first pair 30 and the fourth pair 36 of fastener assemblies 24 located on the fuselage frames 20a and 20d, respectively, provide optimal load transfer between the fuselage frames 20a and 20d and the vertical tail fin assembly 16 when dealing with longitudinal operating forces on the vertical tail fin assembly 16 along the length L of the aircraft 10.

[0026] 10 , a method 142 for securing a vertical tail fin assembly 16 to an aircraft 10 includes a step 144 of securing a first lug member 46 secured to the vertical tail fin assembly 16 to a first end 54 of a first U-shaped hook member 52. The method 142 further includes a step 146 of securing the second end 56 of the first U-shaped hook member 52 to a first fuselage frame 20a constructed of a composite material with a first fastener 58 extending through the second end 56 of the first U-shaped hook member 52 and the first fuselage frame 20a in a first direction 60 transverse to the first fuselage frame 20a.

[0027] Securing the first lug member 46 to the first end 54 of the first U-shaped hook member 52, step 144, includes the first U-shaped hook member 52 having a first prong 62 defining a first opening 64 at the first end 54 of the first U-shaped hook member 52 and a second prong 66 defining a second opening 68 at the first end 54 of the first U-shaped hook member 52, as seen in FIG. 5. The first lug member 46 is disposed between the first prong 62 and the second prong 66 of the first U-shaped hook member 52, as seen in FIG. 6, to define a first lug opening 72 therethrough. The first pin 70 extends through the first opening 64 in the first prong 62, the second opening 68 in the second prong 66, and through a first lug opening 72 in the first lug member 46 such that the first pin 70 extends in a first direction 60 across the first fuselage frame 20a.

[0028] 5 , the method for securing 142 further includes a first pair 35 of U-shaped hook members including a first U-shaped hook member 52 and a second U-shaped hook member 78, the second U-shaped hook member 78 being secured to the first fuselage frame 20a spaced apart from the first U-shaped hook member 52 in a second direction 80 along the first fuselage frame 20a. A second pin (not shown) extends through a first opening 84 in a first prong 82 of a first portion of the second U-shaped hook member 78, a second opening 88 in a second prong 86 of a first end 89 of the second U-shaped hook member 78, and through a second lug opening (not shown) in a second lug member 90 such that the second pin (not shown) extends in the first direction 60 across the first fuselage frame 20a. The second fastener 94 passes through the second end 91 of the second U-shaped hook member 78 and extends through the first fuselage frame 20a in the first direction 60 across the first fuselage frame 20a, as seen in FIG. 4, to secure the second U-shaped hook member 78 to the first fuselage frame 20a.

[0029] 7, the method 142 further includes securing a third lug member 108 to the first end 102 of the third U-shaped hook member 96, wherein a third fixing flange 116 at a second end 114 of the third U-shaped hook member 96 is secured to a second fuselage frame 20b spaced apart from the first fuselage frame 20a. The third U-shaped hook member 96 includes a first prong 98 that defines a first opening 100 at the first end 102 of the third U-shaped hook member 96, and has a second prong 104 that defines a second opening 106 at the first end 102 of the third U-shaped hook member 96, as seen in FIG. The third lug member 108 is disposed between the first prong 98 and the second prong 104 of the third U-shaped hook member 96 and defines a third lug opening (not shown) therethrough. The third pin 110 extends through the first opening 100 of the first prong 98, the second opening 106 of the second prong 104, and through the third lug opening (not shown) of the third lug member 108 such that the third pin 110 extends in a third direction 112 along the second fuselage frame 20b. The third fastener 120 extends through the third fixing flange 116 of the second end 114 of the third U-shaped hook member 96 and the second fuselage frame 20b in a fourth direction 122 transverse to the second fuselage frame 20b, as seen in FIG. 7 .

[0030] 5 , the second pair of U-shaped hook members 37 includes a third U-shaped hook member 96 and a fourth U-shaped hook member 124, with the fourth U-shaped hook member 124 secured to the second fuselage frame 20b spaced apart from the third U-shaped hook member 96 in the third direction 112 along the second fuselage frame 20b. The fourth U-shaped hook member 124 has a first prong 126 defining a first opening 127 at a first end (not shown) of the fourth U-shaped hook member 124, and a second prong 128 defining a second opening 130 at a first end (not shown) of the fourth U-shaped hook member 124. A first end (not shown) of the fourth U-shaped hook member 124 is similar to the first end 102 of the third U-shaped hook member 96 shown in FIG. 7. The fourth lug member 132 is disposed between the first prong 126 and the second prong 128 of the fourth U-shaped hook member 124, as seen in FIG. 3, and defines a fourth lug opening (not shown) therethrough. A fourth pin (not shown) extends through the first opening 127 of the first prong 126, the second opening 130 of the second prong 128, and the fourth lug opening (not shown) of the fourth lug member 132, similar to the third pin 110 seen in FIG. 7, such that the fourth pin (not shown) extends in the third direction 112 along the second fuselage frame 20b. A fourth fastener (not shown), similar to the third fastener 120 of FIG. 7, passes through the fourth fixing flange 134 of the second end (not shown) of the fourth U-shaped hook member 124 and the second fuselage frame 20b as seen in FIG. 2, and extends in a fourth direction 122 across the second fuselage frame 20b, similar to the fixing arrangement of the third fixing flange 116 as seen in FIG. 7.

[0031] The composite material used to construct the first through fourth fuselage frames 20a through 20d includes a five-ply configuration for the layers, and multiple layers are used in this example, including one ply having a nonlinear fiber configuration 136 of fibers, as seen in FIG. 8, as previously described. Two plies have a first linear fiber configuration of fibers 138 extending within an angular range including plus or minus 5 degrees of a plus 30-degree angular displacement from the radial axis R of the nonlinear fiber configuration 136 of the fibers. Another two plies have a second linear fiber configuration of fibers 140 extending within an angular range including plus or minus 5 degrees of a minus 30-degree angular displacement from the radial axis R of the nonlinear fiber configuration 136 of the fibers.

[0032] While various embodiments have been described above, the present disclosure is not limited thereto, and modifications may be made to the disclosed embodiments that fall within the scope of the appended claims. [Explanation of symbols]

[0033] 10 aircraft 12 Fuselage Assembly 14 Wing Assembly 16 Vertical Tail Fin Assembly 18 Outer Panel 20a, 20b, 20c, 20d Fuselage frame 22 fuselage skin 24 Fixing Assembly 26 starboard side 28 port side 30 First Pair 32 Second pair 34 Third pair 35 First pair 36 Fourth Pair 37 Second pair of U-shaped hook members 38 Forward direction 40 backward direction 42 starboard direction 44 port direction 46 First lug member 48 Rear position 50 forward position 52 First U-shaped hook member 54 first end 56 Second end 58 First fastener 60 First Direction 62 First Prong 64 First Opening 66 Second Prong 68 Second Opening 70 First Pin 72 First lug opening 74 First fixed flange 76 Front 78 Second U-shaped hook member 80 Second Direction 82 First Prong 84 First Opening 86 Second Prong 88 Second Opening 89 First end 90 Second lug member 91 Second end 92 Second fixed flange 94 Second Fastener 96 Third U-shaped hook member 98 First Prong 100 First opening 102 first end 104 Second Prong 106 Second Opening 108 Third lug member 110 Third Pin 112 The Third Direction 114 Second end 116 Third fixed flange 118 Front 120 Third Fastener 122 The Fourth Direction 124 Fourth U-shaped hook member 126 First Prong 127 First Opening 128 Second Prong 130 Second Opening 132 Fourth lug member 134 Fourth fixed flange

Claims

1. a fastening assembly for fastening the vertical tail fin assembly to the aircraft, a first lug member secured to the vertical tail fin assembly; a first U-shaped hook member; Equipped with a first end of the first U-shaped hook member engaged with the first lug member; a second end of the first U-shaped hook member is secured to the first fuselage frame constructed of composite material with a first fastener extending through the second end and the first fuselage frame in a first direction across the first fuselage frame; the first U-shaped hook member has a first prong defining a first opening at the first end of the first U-shaped hook member and a second prong defining a second opening at the first end of the first U-shaped hook member; the first lug member is disposed between the first prong and the second prong of the first U-shaped hook member; the fastening assembly further includes a first pin extending through a first lug opening defined by and extending through the first lug member, the first pin passing through the first opening of the first prong, the second opening of the second prong, and engaging the first U-shaped hook member with the first lug member such that the first pin extends in the first direction across the first fuselage frame. Fixing assembly.

2. 2. The anchoring assembly of claim 1, wherein the second end of the first U-shaped hook member includes a first anchoring flange extending along a forward side of the first fuselage frame, and the first fastener extends through the first anchoring flange and the first fuselage frame.

3. a first pair of U-shaped hook members including the first U-shaped hook member and a second U-shaped hook member fixed to the first fuselage frame, the first U-shaped hook member and the second U-shaped hook member being spaced apart from each other in a second direction along the first fuselage frame; the first U-shaped hook member has a first prong defining a first opening at the first end of the first U-shaped hook member, and the second U-shaped hook member has a first prong defining a first opening at the first end of the second U-shaped hook member; the first U-shaped hook member has a second prong defining a second opening at the first end of the first U-shaped hook member, and the second U-shaped hook member has a second prong defining a second opening at the first end of the second U-shaped hook member; the first lug member is disposed between the first prong and the second prong of the first U-shaped hook member of the first pair of U-shaped hook members; a second lug member disposed between the first prong and the second prong of the second U-shaped hook member of the first pair of U-shaped hook members; 3. A fastening assembly according to claim 1 or 2.

4. a first pin extends through the first opening in the first prong of the first U-shaped hook member, the second opening in the second prong of the first U-shaped hook member, and through a first lug opening defined by and extending through the first lug member such that the first pin extends in the first direction across the first fuselage frame; a second pin extends through the first opening in the first prong of the second U-shaped hook member, the second opening in the second prong of the second U-shaped hook member, and through a second lug opening defined by and extending through the second lug member such that the second pin extends in the first direction across the first fuselage frame; The fastening assembly of claim 3 .

5. the second end of the first U-shaped hook member includes a first fixing flange, and the second end of the second U-shaped hook member includes a second fixing flange; the first fastening flange extends along a forward side of the first fuselage frame, with the first fastener extending through the first fastening flange and the first fuselage frame in the first direction across the first fuselage frame; the second fastening flange extends along the front side of the first fuselage frame, and a second fastener extends through the second fastening flange and the first fuselage frame in the first direction across the first fuselage frame.

5. A fastening assembly according to claim 3 or 4.

6. a third U-shaped hook member secured to a second fuselage frame constructed of composite material spaced from the first U-shaped hook member along the length of the aircraft, the third U-shaped hook member having a first prong defining a first opening at a first end of the third U-shaped hook member and a second prong defining a second opening at the first end of the third U-shaped hook member; a third lug member disposed between the first prong and the second prong of the third U-shaped hook member; A fastening assembly according to any one of claims 1 to 5.

7. 7. The anchoring assembly of claim 6, further comprising a third pin extending through a third lug opening defined by and extending through the third lug member, the third pin passing through the first opening in the first prong, the second opening in the second prong of the third U-shaped hook member, and engaging the third U-shaped hook member with the third lug member such that the third pin extends in a third direction along the second fuselage frame.

8. 8. The anchoring assembly according to claim 6 or 7, wherein a second end of the third U-shaped hook member includes a third anchoring flange extending along a forward side of the second fuselage frame, and a third fastener extends through the third anchoring flange and the second fuselage frame in a fourth direction transverse to the second fuselage frame.

9. 9. The anchoring assembly according to claim 6, further comprising a second pair of U-shaped hook members comprising the third U-shaped hook member and a fourth U-shaped hook member secured to the second fuselage frame spaced apart from each other in a third direction along the second fuselage frame.

10. the third U-shaped hook member has a first prong defining a first opening at the first end of the third U-shaped hook member, and the fourth U-shaped hook member has a first prong defining a first opening at the first end of the fourth U-shaped hook member; the third U-shaped hook member has a second prong defining a second opening at the first end of the third U-shaped hook member, and the fourth U-shaped hook member has a second prong defining a second opening at the first end of the fourth U-shaped hook member; the third lug member is disposed between the first prong and the second prong of the third U-shaped hook member; a fourth lug member disposed between the first prong and the second prong of the fourth U-shaped hook member; The fastening assembly of claim 9.

11. a third pin extends through the first opening in the first prong of the third U-shaped hook member, the second opening in the second prong of the third U-shaped hook member, and through a third lug opening defined by and extending through the third lug member such that the third pin extends in the third direction along the second fuselage frame; a fourth pin extends through the first opening in the first prong of the fourth U-shaped hook member, the second opening in the second prong of the fourth U-shaped hook member, and through a fourth lug opening defined by and extending through the fourth lug member such that the fourth pin extends in the third direction along the second fuselage frame; The fastening assembly of claim 10.

12. the second end of the third U-shaped hook member includes a third fixing flange, and the second end of the fourth U-shaped hook member includes a fourth fixing flange; the third fixing flange extends along a forward side of the second fuselage frame, and a third fastener extends through the third fixing flange and the second fuselage frame in a fourth direction transverse to the second fuselage frame; The fourth fixing flange extends along the front side of the second fuselage frame, and a fourth fastener extends through the fourth fixing flange and the second fuselage frame in the fourth direction across the second fuselage frame.

12. A fastening assembly according to claim 10 or 11.

13. The composite material includes a five-ply construction, the five-ply construction comprising: one ply having a nonlinear fiber configuration; two plies having a first linear fiber configuration extending within an angular range including plus or minus 5 degrees of an angular displacement of plus 30 degrees from a radial axis of the nonlinear fiber configuration; two other plies having a second linear fiber configuration extending within an angular range including plus or minus 5 degrees of an angular displacement of minus 30 degrees from the radial axis of the nonlinear fiber configuration; Including, A fastening assembly according to any one of claims 1 to 12.

14. 1. A method for securing a vertical tail fin assembly to an aircraft, comprising: securing a first lug member secured to the vertical tail fin assembly to a first end of a first U-shaped hook member; securing the second end of the first U-shaped hook member to the first fuselage frame constructed of composite material with a first fastener extending through the second end of the first U-shaped hook member and the first fuselage frame in a first direction across the first fuselage frame; Including, The step of securing the first lug member to the first end of the first U-shaped hook member includes: the first U-shaped hook member has a first prong defining a first opening at the first end of the first U-shaped hook member and a second prong defining a second opening at the first end of the first U-shaped hook member; the first lug member is disposed between the first prong and the second prong of the first U-shaped hook member and defines a first lug opening therethrough; a first pin extends through the first opening in the first prong, the second opening in the second prong, and through the first lug opening in the first lug member such that the first pin extends in the first direction across the first fuselage frame; A method for fastening.

15. a first pair of U-shaped hook members comprising the first U-shaped hook member and a second U-shaped hook member, the second U-shaped hook member being secured to the first fuselage frame at a distance from the first U-shaped hook member in a second direction along the first fuselage frame; further comprising a second pin extends through a first opening in a first prong at a first end of the second U-shaped hook member, a second opening in a second prong at the first end of the second U-shaped hook member, and through a second lug opening in a second lug member such that the second pin extends in the first direction across the first fuselage frame; a second fastener passes through a second end of the second U-shaped hook member and extends across the first fuselage frame in the first direction through the first fuselage frame to secure the second U-shaped hook member to the first fuselage frame; 15. The method for fixing according to claim 14.

16. further comprising the step of securing a third lug member to a first end of a third U-shaped hook member by a third fixing flange at a second end of the third U-shaped hook member secured to a second fuselage frame spaced from the first fuselage frame; the third U-shaped hook member has a first prong defining a first opening at the first end of the third U-shaped hook member and a second prong defining a second opening at the first end of the third U-shaped hook member; the third lug member is disposed between the first prong and the second prong of the third U-shaped hook member and defines a third lug opening therethrough; a third pin extends through the first opening in the first prong, the second opening in the second prong, and through the third lug opening in the third lug member such that the third pin extends in a third direction along the second fuselage frame; a third fastener extends through the third fixing flange at the second end of the third U-shaped hook member and the second fuselage frame in a fourth direction transverse to the second fuselage frame; a second pair of U-shaped hook members including the third U-shaped hook member and a fourth U-shaped hook member, the fourth U-shaped hook member being fixed to the second fuselage frame spaced apart from the third U-shaped hook member in the third direction along the second fuselage frame; the fourth U-shaped hook member has a first prong defining a first opening at the first end of the fourth U-shaped hook member and a second prong defining a second opening at the first end of the fourth U-shaped hook member; a fourth lug member disposed between the first prong and the second prong of the fourth U-shaped hook member and defining a fourth lug opening therethrough; a fourth pin passes through the first opening in the first prong, the second opening in the second prong, and extends through the fourth lug opening in the fourth lug member such that the fourth pin extends in the third direction along the second fuselage frame; a fourth fastener extends in the fourth direction across the second fuselage frame through a fourth fastening flange at the second end of the fourth U-shaped hook member and the second fuselage frame; 16. A method for fixing according to claim 14 or 15.

17. The composite material includes a plurality of groups of five-ply constructions, the five-ply constructions comprising: one ply having a nonlinear fiber configuration; two plies having a first linear fiber configuration extending within an angular range including plus or minus 5 degrees of an angular displacement of plus 30 degrees from a radial axis of the nonlinear fiber configuration; two other plies having a second linear fiber configuration extending within an angular range including plus or minus 5 degrees of an angular displacement of minus 30 degrees from the radial axis of the nonlinear fiber configuration; Including, A method for fixation according to any one of claims 14 to 16.

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