Fuselage barrel assemblies and methods of assembling fuselage barrel assemblies

Fuselage barrel assemblies and methods of assembling fuselage barrel assemblies are disclosed herein. The fuselage barrel assemblies include a first barrel section and a second barrel section, which is interfaced with the first barrel section to define a barrel joint between the first barrel section and the second barrel section. The fuselage barrel assemblies also include a split longeron, which extends across the barrel joint and is attached to both the first barrel section and the second barrel section. The split longeron includes a first longeron section, which is attached to the first barrel section, and a second longeron section, which is attached to the second barrel section. The split longeron also includes a longeron joint that attaches the first longeron section to the second longeron section. The methods include methods of assembling the fuselage barrel assemblies.

FIELD

The present disclosure relates generally to fuselage barrel assemblies and to methods of assembling fuselage barrel assemblies and more particularly to fuselage barrel assemblies and methods that utilize a split longeron.

BACKGROUND

During manufacturing of an aircraft, a fuselage barrel assembly may be assembled from a plurality of barrel sections. In certain regions of the fuselage barrel assembly, a longeron may extend between, may interconnect, may provide structural support for two adjacent barrel sections, and/or may reinforce a joint between the two adjacent barrel sections. Such longerons conventionally have been single-piece structures. While effective, installation of such single-piece longerons may be time consuming and/or may require that additional assembly steps be performed subsequent to installation of the single-piece longerons within the fuselage barrel assembly. This adds to the overall time and cost associated with an already cost and space-intensive step of the manufacturing process. Thus, there exists a need for improved fuselage barrel assemblies and/or for improved methods of assembling the improved fuselage barrel assemblies.

SUMMARY

Fuselage barrel assemblies and methods of assembling fuselage barrel assemblies are disclosed herein. The fuselage barrel assemblies include a first barrel section and a second barrel section, which is interfaced with the first barrel section to define a barrel joint between the first barrel section and the second barrel section. The fuselage barrel assemblies also include a split longeron, which extends across the barrel joint and is attached to both the first barrel section and the second barrel section. The split longeron includes a first longeron section, which is attached to the first barrel section via a first plurality of section fasteners, and a second longeron section, which is attached to the second barrel section via a second plurality of section fasteners. The split longeron also includes a longeron joint that attaches the first longeron section to the second longeron section via a plurality of joint fasteners.

The methods include attaching a first longeron section to a first barrel section of a fuselage barrel assembly utilizing a first plurality of section fasteners. The methods also include assembling the first barrel section and a second barrel section to define a barrel joint between the first barrel section and the second barrel section. The methods further include attaching a second longeron section to the second barrel section utilizing a second plurality of section fasteners and attaching the first longeron section to the second longeron section utilizing a plurality of joint fasteners.

DESCRIPTION

FIGS.1-17provide illustrative, non-exclusive examples of aircraft10, fuselage barrel assemblies20, split longerons100, and/or methods200, according to the present disclosure. Elements that serve a similar, or at least substantially similar, purpose are labeled with like numbers in each ofFIGS.1-17, and these elements may not be discussed in detail herein with reference to each ofFIGS.1-17. Similarly, all elements may not be labeled in each ofFIGS.1-17, but reference numerals associated therewith may be utilized herein for consistency. Elements, components, and/or features that are discussed herein with reference to one or more ofFIGS.1-17may be included in and/or utilized with any ofFIGS.1-17without departing from the scope of the present disclosure.

In general, elements that are likely to be included in a given (i.e., a particular) embodiment are illustrated in solid lines, while elements that are optional to a given embodiment are illustrated in dashed lines. However, elements that are shown in solid lines are not essential to all embodiments, and an element shown in solid lines may be omitted from a particular embodiment without departing from the scope of the present disclosure.

FIG.1is a schematic illustration of an example of an aircraft10that includes a fuselage barrel assembly20, according to the present disclosure.FIG.2is a schematic illustration of an example of a first internal frame assembly38that may form a portion of aircraft10ofFIG.1.FIGS.3-5are schematic illustrations of examples of regions of fuselage barrel assembly20ofFIG.1.FIGS.7-15are schematic illustrations of examples of components of a fuselage barrel assembly20that may be assembled utilizing the methods200ofFIG.6.

As collectively illustrated byFIGS.1-5andFIGS.7-17, fuselage barrel assemblies20include a first barrel section30and a second barrel section40. As perhaps best illustrated inFIGS.1,12, and15, first barrel section30and second barrel section40define a barrel joint50therebetween.

As perhaps best illustrated inFIGS.1-5and8-17, fuselage barrel assemblies20also include a split longeron100. Split longeron100extends across barrel joint50and is attached to both first barrel section30and second barrel section40, as perhaps best illustrated inFIGS.1,3,8,12, and15. Split longeron100includes a first longeron section110, a second longeron section130, and a longeron joint150.

As perhaps best illustrated inFIGS.3-5, first longeron section110is attached, or operatively attached, to first barrel section30via a first plurality of section fasteners112. Similarly, second longeron section130is attached, or operatively attached, to second barrel section40via a second plurality of section fasteners132. In addition, longeron joint150attaches, or operatively attaches, first longeron section110to second longeron section130via a plurality of joint fasteners160.

Split longeron100may include any suitable structure that includes first longeron section110, that includes second longeron section130, and/or that includes and/or defines longeron joint150. Additionally or alternatively, split longeron100may include any suitable structure that extends across barrel joint50and/or that is operatively attached to both first barrel section30and second barrel section40. As discussed in more detail herein with reference to methods200, utilization of split longeron100, which includes both first longeron section110and second longeron section130, may permit and/or facilitate improved efficiency during assembly of fuselage barrel assembly20and/or may provide additional clearance for assembly of fuselage barrel assembly20.

First longeron section110may be forward and/or may be in a forward direction14relative to second longeron section130. In some examples, first longeron section110may include a first barrel-contacting region114that interfaces with, contacts, directly contacts, and/or indirectly contacts first barrel section30, as perhaps best illustrated inFIG.3. In some such examples, first barrel-contacting region114may be referred to herein as and/or may be a planar first barrel-contacting region114and/or an at least substantially planar first barrel-contacting region114.

In some examples, first longeron section110may include and/or may be operatively attached to a landing gear fitting116, or a plurality of landing gear fittings116, as perhaps best illustrated inFIGS.2-3. Landing gear fitting116, when present, may be configured to at least partially support a landing gear assembly118of aircraft10. In some such examples, landing gear assembly118may be attached to first longeron section110via landing gear fitting116. In some such examples, first longeron section110may at least partially define a landing gear bay34of aircraft10and/or may at least partially bound landing gear bay34, as illustrated inFIGS.1-3.

As discussed in more detail herein with reference to methods200, utilization of split longerons100that include first longeron section110may permit and/or facilitate improved efficiency during assembly of fuselage barrel assembly20. As an example, first longeron section110may be operatively attached to first barrel section30prior to assembly of first barrel section30with second barrel section40. As another example, and when first longeron section110includes and/or is operatively attached to a plurality of landing gear fittings116, the plurality of landing gear fittings116may be line bored prior to assembly of first barrel section30with second barrel section40. As yet another example, landing gear assembly118may be installed within landing gear bay34prior to assembly of first barrel section30with second barrel section40.

Each of the above benefits may decrease the time required to assemble first barrel section30and second barrel section40. Because fuselage barrel assembly20of aircraft10is large, assembly of fuselage barrel sections, including first barrel section30and second barrel section40, is costly and requires a large amount of space within a factory that manufactures aircraft10. As such, performing any of the above steps prior to assembly of first barrel section30and second barrel section40may provide significant cost savings within the context of the overall manufacturing process for aircraft10.

Second longeron section130may be aft and/or may be in an aft direction16relative to first longeron section110. In some examples, second longeron section130may include a second barrel-contacting region134that interfaces with, contacts, directly contacts, and/or indirectly contacts second barrel section40, as perhaps best illustrated inFIG.3. In some such examples, second barrel-contacting region134may be referred to herein as and/or may be a non-planar, or a curved, second barrel-contacting region134.

Longeron joint150may include any suitable structure that operatively attaches first longeron section110to second longeron section130, such as via plurality of joint fasteners160. In some examples, longeron joint150includes and/or is a lap joint and/or an overlap joint. In some such examples, longeron joint150defines an overlap region156between first longeron section110and second longeron section130, as perhaps best illustrated inFIGS.3-5. In some such examples, first longeron section110may include and/or define a first overlap region120and second longeron section130may include and/or define a second overlap region140. In some such examples, first overlap region120and second overlap region140may overlap with one another, such as along a longitudinal length104of split longeron100, to define longeron joint150.

In some examples, longeron joint150may define a first joint region151, a second joint region152, and a third joint region153, as perhaps best illustrated inFIGS.3-5and16-17. In some such examples, first longeron section110and second longeron section130overlap with one another within first joint region151, within second joint region152, and/or within third joint region153. In some such examples, first joint region151, second joint region152, and third joint region153are oriented at skew angles relative to one another. In some such examples, first joint region151may include and/or be a planar, or at least substantially planar, first joint region151. Additionally or alternatively, second joint region152may include and/or be a planar, or at least substantially planar, second joint region152. Additionally or alternatively, third joint region153may include and/or be a planar, or at least substantially planar, third joint region153.

In some such examples, first joint region151, second joint region152, and third joint region153together may define a Z-shaped splice between first longeron section110and second longeron section130. Such a configuration may permit split longeron100to support and/or to resist compression loads, tension loads, and/or torsional loads applied perpendicular to the elongate axis of split longeron100, and/or torsional loads applied around the elongate axis of split longeron100.

In some examples, longeron joint150may be proximate barrel joint50. As an example, a transverse cross-section of fuselage barrel assembly20, which extends at least partially through barrel joint50, may extend within at least a region of longeron joint150and/or may be within a threshold distance of longeron joint150. Examples of the threshold distance include threshold distances of at most 0.01 meter (m), at most 0.05 m, at most 0.1 m, at most 0.2 m, at most 0.3 m, at most 0.4 m, and at most 0.5 m.

In some examples, split longerons100may include a joint shim170, as illustrated inFIG.3. Joint shim170, when present, may extend and/or may be positioned within longeron joint150. In some examples, joint shim170may be positioned and/or may be compressed between first longeron section110and second longeron section130.

Inclusion of joint shim170within longeron joint150may permit and/or facilitate assembly of fuselage barrel assembly20without a need to include corresponding shim(s) between first barrel section30and first longeron section110and/or between second barrel section40and second longeron section130. In general, longeron joint150may be more accessible than a region that extends between first barrel section30and first longeron section110and/or than a region that extends between second barrel section40and second longeron section130. As such, fuselage barrel assemblies20with split longerons100that include longeron joint150that may receive joint shim170, according to the present disclosure, may be less time-consuming to assemble when compared to conventional fuselage barrel assemblies that include single-piece longerons.

With the above in mind, fuselage barrel assembly20may be free of a shim that extends between first longeron section110and first barrel section30. Stated another way, first longeron section110may be in contact, or in direct physical contact, with first barrel section30. Additionally or alternatively, fuselage barrel assembly20may be free of a shim that extends between second longeron section130and second barrel section40. Stated another way, second longeron section130may be in contact, or in direct physical contact, with second barrel section40.

First barrel section30may include any suitable structure that may be interfaced with second barrel section40to define barrel joint50. As examples, first barrel section may include a first skin31, as illustrated inFIG.1, and/or first internal frame assembly38, as collectively illustrated byFIGS.1-2. In some examples, first barrel section30may be forward, or in forward direction14, relative to second barrel section40. In some examples, first barrel section30may bound, or at least partially bound, landing gear bay34of aircraft10. In some such examples, and as perhaps best illustrated inFIG.2, first internal frame assembly38may bound, may at least partially bound, may support, may at least partially support, may define, and/or may at least partially define landing gear bay34. In some examples, and as perhaps best illustrated inFIG.1, first barrel section30may be attached, or operatively attached, to at least a region of a wing12of aircraft10. In some examples, first barrel section30may define a first edge32that may at least partially define barrel joint50.

In some examples, and as perhaps best illustrated inFIG.3, first barrel section30may define and/or include a first longeron-contacting region36. First longeron-contacting region36may be configured to interface with first longeron section110and/or with first barrel-contacting region114thereof. In some such examples, first longeron-contacting region36may be a planar first longeron-contacting region36or an at least substantially planar first longeron-contacting region36.

Second barrel section40may include any suitable structure that may be interfaced with first barrel section30to define barrel joint50. As examples, second barrel section40may include a second skin41as illustrated inFIG.1. In some examples, second barrel section40may be aft, or in aft direction16, relative to first barrel section30. In some examples, second barrel section40may define a second edge42that may at least partially define barrel joint50.

In some examples, and as perhaps best illustrated inFIG.3, second barrel section40may define and/or include a second longeron-contacting region46. Second longeron-contacting region46may be configured to interface with second longeron section130and/or with second barrel-contacting region134thereof. In some such examples, second longeron-contacting region46may be a non-planar second longeron-contacting region46.

First plurality of section fasteners112, which also may be referred to herein as fasteners112, may differ from, be distinct from, and/or be spaced-apart from second plurality of section fasteners132and/or plurality of joint fasteners160. Additionally or alternatively, first plurality of section fasteners112may be spaced-apart from second barrel section40and/or from second longeron section130.

Second plurality of section fasteners132, which also may be referred to herein as fasteners132, may differ from, be distinct from, and/or be spaced-apart from first plurality of section fasteners112and/or plurality of joint fasteners160. Additionally or alternatively, second plurality of section fasteners132may be spaced-apart from first barrel section30and/or from first longeron section110.

At least a subset of the plurality of joint fasteners160, which also may be referred to herein as fasteners160, may differ from, may be distinct from, and/or may be spaced-apart from first plurality of section fasteners112and/or second plurality of section fasteners132. In some examples, a first subset161of the plurality of joint fasteners160may be spaced-apart from first barrel section30. Additionally or alternatively, a second subset162of the plurality of joint fasteners160may be spaced-apart from second barrel section40. Additionally or alternatively, a third subset163of the plurality of joint fasteners160may attach, or operatively attach, split longeron100to first barrel section30. Additionally or alternatively, a fourth subset164of the plurality of joint fasteners160may attach, or operatively attach, split longeron100to second barrel section40.

Turning toFIG.1, aircraft10and/or fuselage barrel assembly20thereof may have and/or define a first side21and a second side22, which may be opposed to first side21. In some such examples, aircraft10and/or fuselage barrel assembly20thereof may include a first split longeron101, which may be positioned on first side21and a second split longeron102, which may be positioned on second side22.

FIG.6is a flowchart depicting examples of methods200of assembling a fuselage barrel assembly, according to the present disclosure, such as fuselage barrel assembly20ofFIGS.1-5.FIGS.7-17illustrate regions and/or components of a fuselage barrel assembly20during various steps of the methods ofFIG.6, withFIG.7illustrating a partially assembled fuselage barrel assembly prior to performing the methods ofFIG.6.

Methods200include attaching a first longeron section to a first barrel section at210and may include attaching a landing gear fitting at220, line boring the landing gear fitting at230, and/or attaching a landing gear assembly at240. Methods200also include assembling the first barrel section and a second barrel section at250and attaching a second longeron section to the second barrel section at260. Methods200also may include positioning a joint shim at270and include attaching the first longeron section to the second longeron section at280.

Attaching the first longeron section to the first barrel section at210may include attaching the first longeron section to the first barrel section with, via, and/or utilizing a first plurality of section fasteners. Examples of the first longeron section are disclosed herein with reference to first longeron section110of split longeron100. Examples of the first barrel section are disclosed herein with reference to first barrel section30of fuselage barrel assembly20. Examples of the first plurality of section fasteners are disclosed herein with reference to first plurality of section fasteners112.

FIGS.8-17illustrate regions of a fuselage barrel assembly20subsequent to performing the attaching at210. More specifically,FIGS.8-17illustrate first longeron section110attached to first barrel section30. This attachment is via the first plurality of section fasteners112, as illustrated inFIG.8.

In some examples, the attaching at210may include extending each first fastener of the first plurality of section fasteners through a corresponding first fastener hole, which extends through both the first longeron section and the first barrel section. In some such examples, the attaching at210includes urging a corresponding first region of the first longeron section and the first barrel section toward one another utilizing each first section fastener.

In some examples, the attaching at210includes establishing direct physical contact between the first longeron section and the first barrel section. In some examples, the attaching at210includes attaching the first longeron section to the first barrel section without positioning a first shim between the first longeron section and the first barrel section. Stated another way, the attaching at210may include attaching the first longeron section and the first barrel section to one another without, or without a need to, shim a first interface between the first longeron section and the first barrel section.

The attaching at210may be performed with any suitable timing and/or sequence during methods200. As examples, the attaching at210may be performed prior to the line boring at230and/or the attaching at240. As additional examples, the attaching at210may be performed prior to, subsequent to, and/or at least partially concurrently with the attaching at220, the assembling at250, the attaching at260, the positioning at270, and/or the attaching at280.

Attaching the landing gear fitting at220may include attaching the landing gear fitting to the first longeron section. Examples of the landing gear fitting are disclosed herein with reference to landing gear fitting116. The attaching at220may include attaching such that the landing gear supports, or is configured to support, the landing gear assembly and/or such that the landing gear fitting permits and/or facilitates selective deployment and/or stowage of the landing gear assembly. In some examples, and as discussed, the aircraft may include a plurality of landing gear fittings, which may be distinct and/or spaced-apart from one another. In some such examples, the attaching at220may include attaching the plurality of landing gear fittings to corresponding locations on the first longeron section. In some examples, one or more landing gear fittings may be pre-attached to and/or integral with the first longeron section. In such examples, the one or more landing gear fittings already may be present and/or the attaching at220may not be utilized.

The attaching at220may be performed with any suitable timing and/or sequence during methods200. As examples, the attaching at220may be performed subsequent to the attaching at210, prior to the attaching at210, at least partially concurrently with the attaching at210, and/or prior to the line boring at230. As additional examples, the attaching at220may be performed prior to, subsequent to, and/or at least partially concurrently with the attaching at240the assembling at250, the attaching at260, the positioning at270, and/or the attaching at280. As discussed, it may be beneficial to perform the attaching at220prior to the assembling at250; however, this is not required.

It may be beneficial for the landing gear fitting to be precisely aligned with a remainder of the fuselage barrel assembly and/or with at least one other landing gear fitting of the plurality of landing gear fittings. With this in mind, and in some examples, methods200include line boring the landing gear fitting at230. The line boring may be utilized to establish a precise alignment between a bore of the landing gear fitting and the remainder of the fuselage barrel assembly and/or may be utilized to establish a precise alignment among two or more bores of two or more spaced-apart landing gear fittings.

The line boring at230may be performed with any suitable timing and/or sequence during methods200. As examples, the line boring at230may be performed subsequent to the attaching at210, subsequent to the attaching at220, and/or prior to the attaching at240. As additional examples, the line boring at230may be performed prior to, subsequent to, and/or at least partially concurrently with the assembling at250, the attaching at260, the positioning at270, and/or the attaching at280. As discussed, it may be beneficial to perform the line boring at230prior to the assembling at250; however, this is not required.

Attaching the landing gear assembly at240may include attaching the landing gear assembly to the landing gear fitting. The attaching at240may be performed with any suitable timing and/or sequence during methods200. As examples, the attaching at240may be performed subsequent to the attaching at210, subsequent to the attaching at220, and/or subsequent to the line boring at230. As additional examples, the attaching at240may be performed prior to, subsequent to, and/or at least partially concurrently with the assembling at250, the attaching at260, the positioning at270, and/or the attaching at280. As discussed, it may be beneficial to perform the attaching at240prior to the assembling at250; however, this is not required.

Assembling the first barrel section and the second barrel section at250may include assembling the first barrel section and the second barrel section to form and/or to define a barrel joint between the first barrel section and the second barrel section. Examples of the second barrel section are disclosed herein with reference to second barrel section40of fuselage barrel assembly20. Examples of the barrel joint are disclosed herein with reference to barrel joint50.

In some examples, the assembling at250may include aligning a first edge of the first barrel section with a second edge of the second barrel section. Examples of the first edge are disclosed herein with reference to first edge32. Examples of the second edge are disclosed herein with reference to second edge42. In some such examples, the assembling at250further may include moving the first barrel section and/or the second barrel section. The moving may be such that the first edge and the second edge are proximate one another, such that the first edge and the second edge contact one another, and/or such that the first edge and the second edge define a barrel interface region between the first barrel section and the second barrel section.

In some examples, the first barrel section includes a first skin and a first internal frame assembly. Examples of the first skin are disclosed herein with reference to first skin31. Examples of the first internal frame assembly are disclosed herein with reference to first internal frame assembly38. In some such examples, the first skin may extend between an attached region of the first longeron section and the first internal frame assembly. In some such examples, a gap may separate an unattached region of the first longeron section and the first internal frame assembly. In some such examples, the assembling at250may include positioning a corresponding region of the second barrel section within the gap.

The assembling at250may be performed with any suitable timing and/or sequence during methods200. As examples, the assembling at250may be performed prior to, subsequent to, and/or at least partially concurrently with the attaching at210, the attaching at220, the line boring at230, the attaching at240, the attaching at260, the positioning at270, and/or the attaching at280.

Attaching the second longeron section to the second barrel section at260may include attaching the second longeron section to the second barrel section with, via, and/or utilizing a second plurality of section fasteners. Examples of the second longeron section are disclosed herein with reference to second longeron section130. Examples of the second plurality of section fasteners are disclosed herein with reference to second plurality of section fasteners132.

In some examples, the attaching at260may include extending each second section fastener of the second plurality of section fasteners through a corresponding second fastener hole, which extends through both the second longeron section and the second barrel section. In some such examples, the attaching at260includes urging a corresponding second region of the second longeron section and the second barrel section toward one another utilizing each second section fastener.

In some examples, the attaching at260includes establishing direct physical contact between the second longeron section and the second barrel section. In some examples, the attaching at260includes attaching the second longeron section to the second barrel section without positioning a second shim between the second longeron section and the second barrel section. Stated another way, the attaching at260may include attaching the second longeron section and the second barrel section to one another without, or without a need to, shim a second interface between the second longeron section and the second barrel section.

The attaching at260may be performed with any suitable timing and/or sequence during methods200. As examples, the attaching at260may be performed prior to, subsequent to, and/or at least partially concurrently with the attaching at210, the attaching at220, the line boring at230, the attaching at240, the assembling at250, the positioning at270, and/or the attaching at280.

In a specific example, and as illustrated inFIGS.9-12, the assembling at250may be performed subsequent to the attaching at210and prior to the attaching at260. In some such examples, and as also illustrated inFIGS.9-12, a gap60may separate an unattached region122of first longeron section110from first internal frame assembly38of first barrel section30. In such examples, and as illustrated by the progression fromFIG.9toFIG.10toFIG.11, the assembling at250may include positioning a corresponding region of second barrel section40within gap60. Subsequently, and as illustrated inFIG.12, the attaching at260may be performed to attach second longeron section130to second barrel section40. As illustrated, this attachment process may include insertion of a region of second longeron section130, such as second overlap region140, within gap60.

Because both the corresponding region of second barrel section40and the region of second longeron section130ultimately are positioned within gap60, gap60is sized to accommodate the thickness of both the corresponding region of second barrel section40and the thickness of the region of second longeron section130. As such, gap60provides additional clearance for the corresponding region of second barrel section40during the assembling at250. This clearance is illustrated inFIGS.10-11and indicated at62.

Gap60and clearance62also are illustrated inFIGS.16-17, which are examples of transverse cross-sectional views of longeron joint150. As illustrated inFIG.16, and subsequent to the attaching at210and the assembling at250but prior to the attaching at260, the corresponding region of second barrel section40may be positioned within gap60. As illustrated, gap60is wider than a thickness of the corresponding region of second barrel section40, thereby providing clearance62, which may facilitate the assembling at250and/or may provide additional clearance for the corresponding region of second barrel section40during the assembling at250. Subsequently, and as illustrated inFIG.17, the attaching at260may be performed to attach second longeron section130to second barrel section40. As illustrated, this attachment process may include insertion of a region of second longeron section130within gap60.

In another specific example, and as illustrated inFIGS.13-15, the assembling at250may be performed subsequent to both the attaching at210and the attaching at260. With this in mind,FIG.13illustrates first barrel section30with first longeron section110attached thereto and also illustrates second barrel section40with second longeron section130attached thereto. Similar to the configuration that is illustrated inFIGS.9-12, gap60separates unattached region122of first longeron section110from first internal frame assembly38of first barrel section30. In such examples, and as illustrated by the progression fromFIG.13toFIG.14toFIG.15, the assembling at250may include simultaneously positioning the corresponding region of second barrel section40and the region of second longeron section130within gap60. In such a configuration, clearance62ofFIGS.9-12may not be present, or may have a smaller magnitude when compared to the configuration ofFIGS.13-15. However, an insertion distance64for second barrel section40and second longeron section130, within gap60may be relatively short. In addition, attachment of second longeron section130to second barrel section40may provide additional support for second barrel section40, thereby facilitating the assembling at250.

In some examples of methods200, design and/or build tolerances of one or more components of the fuselage barrel assembly may be such that the first barrel section and the second barrel section misaligned subsequent to the assembling at250. In addition, and as discussed, utilization of split longerons that include the first longeron section and the second longeron section, according to the present disclosure, may decrease, or even eliminate, a need to correct for this misalignment by shimming between the first longeron section and the first barrel section and/or between the second longeron section and the second barrel section.

Instead, and when this misalignment occurs, methods200may include positioning the joint shim at270. The positioning at270may include positioning the joint shim between the first longeron section and the second longeron section, such as to permit and/or facilitate adjustment of the relative orientation between the first barrel section and the second barrel section and/or alignment of the first barrel section and the second barrel section to one another.

The positioning at270may be performed with any suitable timing and/or sequence during methods200. As examples, the positioning at270may be performed subsequent to the attaching at210, subsequent to the assembling at250, subsequent to the attaching at260, and/or prior to the attaching at280. As additional examples, the positioning at270may be performed prior to, subsequent to, and/or at least partially concurrently with the attaching at220, the line boring at230, and/or the attaching at240.

Attaching the first longeron section to the second longeron section at280may include attaching the first longeron section to the second longeron section with, via, and/or utilizing a plurality of joint fasteners. Examples of the plurality of joint fasteners are disclosed herein with reference to the plurality of joint fasteners160.

In some examples, the attaching at280may include extending each joint fastener of the plurality of joint fasteners through a corresponding joint fastener hole, which extends through both the first longeron section and the second longeron section. In some such examples, the attaching at280includes urging a corresponding first region of the first longeron section and a second region of the second longeron section toward one another utilizing each joint section fastener.

The attaching at280may be performed with any suitable timing and/or sequence during methods200. As examples, the attaching at280may be performed prior to, subsequent to, or at least partially concurrently with the attaching at210, the attaching at220, the line boring at230, the attaching at240, the assembling at250, and/or the attaching at260. As another example, the attaching at280may be performed subsequent to the positioning at270.

Illustrative, non-exclusive examples of inventive subject matter according to the present disclosure are described in the following enumerated paragraphs:A1. A fuselage barrel assembly (20) for an aircraft (10), the fuselage barrel assembly (20) comprising:a first barrel section (30);a second barrel section (40) interfaced with the first barrel section (30) to define a barrel joint (50) between the first barrel section (30) and the second barrel section (40); anda split longeron (100) that extends across the barrel joint (50) and is attached to both the first barrel section (30) and the second barrel section (40), the split longeron (100) including:(i) a first longeron section (110) that is attached to the first barrel section (30), optionally via a first plurality of section fasteners (112);(ii) a second longeron section (130) that is attached to the second barrel section (40), optionally via a second plurality of section fasteners (132); and(iii) a longeron joint (150) that attaches the first longeron section (110) to the second longeron section (130) via a plurality of joint fasteners (160).A2. The fuselage barrel assembly (20) of paragraph A1, wherein the first longeron section (110) is forward of the second longeron section (130).A3. The fuselage barrel assembly (20) of any of paragraphs A1-A2, wherein the first longeron section (110) includes a first barrel-contacting region (114), a planar first barrel-contacting region (114), or at an at least substantially planar first barrel-contacting region (114) that interfaces with the first barrel section (30).A4. The fuselage barrel assembly (20) of any of paragraphs A1-A3, wherein the first longeron section (110) further includes a landing gear fitting (116) configured to at least partially support a landing gear assembly (118) of the aircraft (10).A5. The fuselage barrel assembly (20) of paragraph A4, wherein the fuselage barrel assembly (20) further includes the landing gear assembly (118), wherein the landing gear assembly (118) is attached to the first longeron section (110) via the landing gear fitting (116).A6. The fuselage barrel assembly (20) of any of paragraphs A1-A5, wherein the first longeron section (110) at least one of:(i) at least partially defines a landing gear bay (34) of the aircraft (10); and(ii) at least partially bounds the landing gear bay (34) of the aircraft (10).A7. The fuselage barrel assembly (20) of any of paragraphs A1-A6, wherein the second longeron section (130) is aft of the first longeron section (110).A8. The fuselage barrel assembly (20) of any of paragraphs A1-A7, wherein the second longeron section (130) includes a second barrel-contacting region (134) or a non-planar second barrel-contacting region (134) that interfaces with the second barrel section (40).A9. The fuselage barrel assembly (20) of any of paragraphs A1-A8, wherein the longeron joint (150) at least one of:(i) includes a lap joint;(ii) is the lap joint; and(iii) defines an overlap region (156) between the first longeron section (110) and the second longeron section (130).A10. The fuselage barrel assembly (20) of any of paragraphs A1-A9, wherein the first longeron section (110) includes a first overlap region (120), wherein the second longeron section (130) includes a second overlap region (140), and further wherein the first overlap region (120) and the second overlap region (140) overlap with one another, along a longitudinal length of the split longeron (100), to define the longeron joint (150).A11. The fuselage barrel assembly (20) of any of paragraphs A1-A10, wherein the longeron joint (150) includes a first joint region (151), a second joint region (152), and a third joint region (153), and further wherein the first longeron section (110) and the second longeron section (130) overlap with one another within the first joint region (151), within the second joint region (152), and within the third joint region (153).A12. The fuselage barrel assembly (20) of paragraph A11, wherein the first joint region (151), the second joint region (152), and the third joint region (153) are oriented at skew angles relative to one another.A13. The fuselage barrel assembly (20) of any of paragraphs A11-A12, wherein at least one of:(i) the first joint region (151) is a first planar, or at least substantially planar, joint region (151);(ii) the second joint region (152) is a second planar, or at least substantially planar, joint region (152); and(iii) the third joint region (153) is a third planar, or at least substantially planar, joint region (153).A14. The fuselage barrel assembly (20) of any of paragraphs A11-A13, wherein the first joint region (151), the second joint region (152), and the third joint region (153) together define a Z-shaped splice between the first longeron section (110) and the second longeron section (130).A15. The fuselage barrel assembly (20) of any of paragraphs A1-A14, wherein a transverse cross-section of the fuselage barrel assembly (20), which extends at least partially through the barrel joint (50), at least one of:(i) extends within at least a region of the longeron joint (150); and(ii) is within a threshold distance of the longeron joint (150), optionally wherein the threshold distance is one of at most 0.01 meter (m), at most 0.05 m, at most 0.1 m, at most 0.2 m, at most 0.3 m, at most 0.4 m, and at most 0.5 m.A16. The fuselage barrel assembly (20) of any of paragraphs A1-A15, wherein the split longeron (100) further includes a joint shim (170) positioned within the longeron joint (150) and compressed between the first longeron section (110) and the second longeron section (130).A17. The fuselage barrel assembly (20) of any of paragraphs A1-A16, wherein the first barrel section (30) is forward of the second barrel section (40).A18. The fuselage barrel assembly (20) of any of paragraphs A1-A17, wherein the first barrel section (30) at least partially bounds a/the landing gear bay (34) of the aircraft (10).A19. The fuselage barrel assembly (20) of any of paragraphs A1-A18, wherein the first barrel section (30) is attached to at least a region of a wing (12) of the aircraft (10).A20. The fuselage barrel assembly (20) of any of paragraphs A1-A19, wherein the first barrel section (30) includes a first longeron-contacting region (36), a planar first longeron-contacting region (36), or an at least substantially planar first longeron-contacting region (36) that interfaces with the first longeron section (110).A21. The fuselage barrel assembly (20) of any of paragraphs A1-A20, wherein the second barrel section (40) is aft of the first barrel section (30).A22. The fuselage barrel assembly (20) of any of paragraphs A1-A21, wherein the second barrel section (40) includes a second longeron-contacting region (46) or a non-planar second longeron-contacting region (46) that interfaces with the second longeron section (130).A23. The fuselage barrel assembly (20) of any of paragraphs A1-A22, wherein the first plurality of section fasteners (112) at least one of:(i) is spaced-apart from the second barrel section (40);(ii) is spaced-apart from the second longeron section (130); and(iii) is spaced-apart from the second plurality of section fasteners (132).A24. The fuselage barrel assembly (20) of any of paragraphs A1-A23, wherein the second plurality of section fasteners (132) at least one of:(i) is spaced-apart from the first barrel section (30);(ii) is spaced-apart from the first longeron section (110); and(iii) is spaced-apart from the first plurality of section fasteners (112).A25. The fuselage barrel assembly (20) of any of paragraphs A1-A24, wherein at least one of:(i) a first subset (161) of the plurality of joint fasteners (160) is spaced-apart from the first barrel section (30);(ii) a second subset (162) of the plurality of joint fasteners (160) is spaced-apart from the second barrel section (40);(iii) a third subset (163) of the plurality of joint fasteners (160) attaches the split longeron (100) to the first barrel section (30); and(iv) a fourth subset (164) of the plurality of joint fasteners (160) attaches the split longeron (100) to the second barrel section (40).A26. The fuselage barrel assembly (20) of any of paragraphs A1-A25, wherein the split longeron (100) is a first split longeron (101) and is positioned on a first side (21) of the fuselage barrel assembly (20), and further wherein the fuselage barrel assembly (20) includes a second split longeron (102) positioned on an opposed second side (22) of the fuselage barrel assembly (20).A27. The fuselage barrel assembly (20) of any of paragraphs A1-A26, wherein at least one of:(i) the fuselage barrel assembly (20) is free of a first shim that extends between the first longeron section (110) and the first barrel section (30);(ii) the first longeron section (110) is in direct physical contact with the first barrel section (30);(iii) the fuselage barrel assembly (20) is free of a second shim that extends between the second longeron section (130) and the second barrel section (40); and(iv) the second longeron section (130) is in direct physical contact with the second barrel section (40).B1. A method (200) of assembling a fuselage barrel assembly (20) of an aircraft (10), the method (200) comprising:attaching (210) a first longeron section (110) to a first barrel section (30) of the fuselage barrel assembly (20) utilizing a first plurality of section fasteners (112);assembling (250) the first barrel section (30) and a second barrel section (40) to define a barrel joint (50) between the first barrel section (30) and the second barrel section (40);attaching (260) a second longeron section (130) to the second barrel section (40) utilizing a second plurality of section fasteners (132); andattaching (280) the first longeron section (110) to the second longeron section (130) utilizing a plurality of joint fasteners (160).B2. The method (200) of paragraph B1, wherein, prior to the assembling (250) the first barrel section (30) and the second barrel section (40), the method (200) further includes attaching (220) a landing gear fitting (116) to the first longeron section (110).B3. The method (200) of paragraph B2, wherein, subsequent to the attaching (220) the landing gear fitting (116) to the first longeron section (110), the method (200) further includes line boring (230) the landing gear fitting (116), optionally wherein the line boring (230) is performed prior to the assembling (250) the first barrel section (30) and the second barrel section (40).B4. The method (200) of any of paragraphs B2-B3, wherein, subsequent to the attaching (220) the landing gear fitting (116) to the first longeron section (110), the method (200) further includes attaching (240) a landing gear assembly (118) to the landing gear fitting (116), optionally wherein the attaching (240) the landing gear assembly (118) is performed prior to the assembling (250) the first barrel section (30) and the second barrel section (40), and further optionally wherein the attaching (240) the landing gear assembly (118) is performed subsequent to a/the line boring (230) the landing gear fitting (116).B5. The method (200) of any of paragraphs B1-B4, wherein the attaching (210) the first longeron section (110) to the first barrel section (30) is performed prior to the assembling (250) the first barrel section (30) and the second barrel section (40).B6. The method (200) of any of paragraphs B1-B5, wherein the attaching (210) the first longeron section (110) to the first barrel section (30) includes extending each first section fastener of the first plurality of section fasteners (112) through a corresponding first fastener hole, which extends through both the first longeron section (110) and the first barrel section (30), and subsequently urging a corresponding first region of the first longeron section (110) and the first barrel section (30) toward one another utilizing the each first section fastener.B7. The method (200) of any of paragraphs B1-B6, wherein the attaching (210) the first longeron section (110) to the first barrel section (30) includes at least one of:(i) establishing direct physical contact between the first longeron section (110) and the first barrel section (30); and(ii) attaching without positioning a first shim between the first longeron section (110) and the first barrel section (30).B8. The method (200) of any of paragraphs B1-B7, wherein the assembling (250) the first barrel section (30) and the second barrel section (40) is one of:(i) prior to the attaching (260) the second longeron section (130) to the second barrel section (40); and(ii) subsequent to the attaching (260) the second longeron section (130) to the second barrel section (40).B9. The method (200) of any of paragraphs B1-B8, wherein the assembling (250) the first barrel section (30) and the second barrel section (40) includes aligning a first edge (32) of the first barrel section (30) with a second edge (42) of the second barrel section (40) and moving at least one of the first barrel section (30) and the second barrel section (40) at least one of:(i) such that the first edge (32) and the second edge (42) are proximate one another;(ii) such that the first edge (32) and the second edge (42) contact one another; and(iii) such that the first edge (32) and the second edge (42) define a barrel interface region between the first barrel section (30) and the second barrel section (40).B10. The method (200) of any of paragraphs B1-B9, wherein the first barrel section (30) includes a first skin (31) and a first internal frame assembly (38), wherein the first skin (31) extends between an attached region of the first longeron section (110) and the first internal frame assembly (38), wherein a gap (60) separates an unattached region (122) of the first longeron section (110) and the first internal frame assembly (38), and further wherein the assembling (250) the first barrel section (30) and the second barrel section (40) includes positioning a corresponding region of the second barrel section (40) within the gap (60).B11. The method (200) of paragraph B10, wherein the attaching (260) the second longeron section (130) to the second barrel section (40) includes positioning a corresponding region of the second longeron section (130) within the gap (60).B12. The method (200) of any of paragraphs B1-B11, wherein the attaching (260) the second longeron section (130) to the second barrel section (40) includes extending each second section fastener of the second plurality of section fasteners (132) through a corresponding second fastener hole, which extends through both the second longeron section (130) and the second barrel section (40), and subsequently urging a corresponding second region of the second longeron section (130) and the second barrel section (40) toward one another utilizing the each second section fastener.B13. The method (200) of any of paragraphs B1-B12, wherein the attaching (260) the second longeron section (130) to the second barrel section (40) includes at least one of:(i) establishing direct physical contact between the second longeron section (130) and the second barrel section (40); and(ii) attaching without positioning a second shim between the second longeron section (130) and the second barrel section (40).B14. The method (200) of any of paragraphs B1-B13, wherein the attaching (280) the first longeron section (110) to the second longeron section (130) is performed subsequent to the assembling (250) the first barrel section (30) and the second barrel section (40).B15. The method (200) of any of paragraphs B1-B14, wherein the attaching (280) the first longeron section (110) to the second longeron section (130) includes extending each joint fastener of the plurality of joint fasteners (160) through a corresponding joint fastener hole, which extends through both the first longeron section (110) and the second longeron section (130), and subsequently urging a corresponding first region of the first longeron section (110) and a second region of the second longeron section (130) toward one another utilizing the each joint section fastener.B16. The method (200) of any of paragraphs B1-B15, wherein, prior to the attaching (280) the first longeron section (110) to the second longeron section (130), the method (200) further includes positioning (270) a joint shim (170) between the first longeron section (110) and the second longeron section (130), and optionally wherein the attaching (280) the first longeron section (110) to the second longeron section (130) includes compressing the joint shim (170) between the first longeron section (110) and the second longeron section (130).B17. The method (200) of any of paragraphs B1-B16, wherein the fuselage barrel assembly (20) includes any suitable structure of any of the fuselage barrel assemblies of any of paragraphs A1-A27.C1. The use of a split longeron (100) to operatively support an interface between a first barrel section (30) and a second barrel section (40) within a fuselage barrel assembly (20) of an aircraft (10).C2. The use of any of the fuselage barrel assemblies of any of paragraphs A1-A27 with any of the methods (200) of any of paragraphs B1-B17.C3. The use of any of the methods (200) of any of paragraphs B1-B17 with any of the fuselage barrel assemblies of any of paragraphs A1-A27.

As used herein, the terms “selective” and “selectively,” when modifying an action, movement, configuration, or other activity of one or more components or characteristics of an apparatus, mean that the specific action, movement, configuration, or other activity is a direct or indirect result of user manipulation of an aspect of, or one or more components of, the apparatus.

As used herein, “at least substantially,” when modifying a degree or relationship, may include not only the recited “substantial” degree or relationship, but also the full extent of the recited degree or relationship. A substantial amount of a recited degree or relationship may include at least 75% of the recited degree or relationship. For example, an object that is at least substantially formed from a material includes objects for which at least 75% of the objects are formed from the material and also includes objects that are completely formed from the material. As another example, a first length that is at least substantially as long as a second length includes first lengths that are within 75% of the second length and also includes first lengths that are as long as the second length.