Construction method for constructing at least two fleets and aircraft fleet

Abstract

The present invention relates to a construction method and a fleet of aircraft for constructing at least two fleets, wherein each aircraft has a front part (12), the front part including windows (30, 32), frame members (34) of the windows, and a front windshield (36), characterized in that, for each aircraft, the method comprises: ● a step of constructing a module (16), the module being composed of all the frame members (34) of the windows and the front windshield (36) allowing observation from the cockpit, the form of the module being completely identical and consistent for all aircraft of the fleets and not depending on the form of the fuselage of the aircraft; ● a step of constructing an adjacent section (20) of the fuselage, the form of at least a part of the edge (28) of the section being completely identical to the edge of the module (16) so that the module (16) can be directly assembled with the adjacent section (20), regardless of the aircraft of the fleets.

Description

[0001] The present invention relates to the field of methods for building fuselages of aircraft, in particular dedicated to passenger and / or cargo transport, and in particular for building the front part thereof. More specifically, the invention proposes a method for building fuselages for a plurality of fleets of aircraft of different series and the fleet thus obtained. Technical Field

[0002] Aircraft dedicated to passenger and / or cargo transport are classified by series. For each series, the aircraft have common features in terms of the number of passengers, the size of the aircraft or the size of some of its elements (and for example the diameter of the fuselage, the wingspan, etc.), the range in terms of the flight distance (especially for short, medium, or long-distance flights), the number of corridors in the cabin, and / or any other significant feature. These features result in a different configuration from one series to another. Therefore, depending on the series, the aircraft provides different front part forms. The form of the fuselage dedicated to each series of aircraft (especially in the area of ​​windows and windshield front deflector) is generated according to each series. Background Art

[0003] Patent FR 2933377 filed by the applicant on July 1, 2008 relates to a Figure 1 . It describes the idea that a first section 2 comprising a cockpit 4 and an electronics compartment 6 dedicated to technical applications has a high degree of commonality between different aircraft. The method therefore consists in providing a second connecting section 8 with a tapered section for assembling the first section 2 with the rest of the fuselage, which for its part has a different form depending on the aircraft.

[0004] Therefore, in order to carry out the assembly with the fuselage, it is necessary to provide an intermediate section 8 allowing adaptation to the different forms of fuselage depending on the aircraft model.

[0005] The purpose of the present invention is to improve the construction of the front part of an aircraft by avoiding reliance on a middle section and also proposing to construct only the areas of the windows and the windshield, which are complex to construct. Summary of the invention

[0006] To this end, the invention relates to a method for building a fleet of at least two aircraft of different series, wherein each aircraft has a front part comprising a window, a frame for said window, and a front wind deflector, and wherein the general form of said front part differs from one series to another, characterized in that, for each aircraft, said method comprises:

[0007] a step of constructing a module consisting of the frame elements of all the windows allowing viewing from the cockpit and the windshield, the form of which is identical and consistent for all the aircraft of the fleet and is independent of the form of the fuselage of the aircraft;

[0008] • A step of building a section of the fuselage, at least part of the edge of which has a form identical to that of the edge of the module so that the module can be assembled directly with the adjacent section, whatever the aircraft of the fleet.

[0009] The construction method may have at least one of the following optional features alone or in combination.

[0010] The step of constructing the module consists in producing the module as a complete panel comprising a single piece and a single block.

[0011] The complete panel produced is formed from the frame elements and the wind deflector, and the module is reinforced in that the reinforcements are arranged differently from the reinforcements of the adjoining sections.

[0012] The reinforcements are at least partially arranged in an isogrid pattern on the modules and at least partially circumferentially on the adjacent sections.

[0013] The module is produced so that, when assembled, its bottom edge abuts against the sealed front bottom side of the aircraft.

[0014] The module is produced such that, when assembled, its top edge at least partially abuts against the circumferential frame closest to the most upstream edge of the landing gear compartment.

[0015] The invention also relates to an aircraft fleet having aircraft of different series, wherein each aircraft comprises window frame elements, windows, and windshield front fairings, and wherein the overall form of the front part differs from one series to another, characterised in that, for each aircraft, all said window frame elements and said windshield front fairings form a one-piece module, the form of said module being exactly the same and consistent for all aircraft of the same series of said fleet and not depending on the form of the fuselage of said aircraft, the edges of said module forming a profile that is exactly the same as the profile of the edges of an adjacent section to which said module is directly assembled, regardless of the aircraft of the same series of said fleet.

[0016] The aircraft fleet may have at least one of the following optional features, either alone or in combination.

[0017] The module comprises a one-piece and monolithic complete panel.

[0018] The frame element and the wind deflector form a reinforced integral panel, wherein the reinforcements are arranged differently from the reinforcements of the adjoining sections.

[0019] The reinforcements are at least partially arranged in an isogrid pattern on the modules and at least partially circumferentially on the adjacent sections.

[0020] The bottom edge of the module abuts the front bottom side of the seal.

[0021] The top edge of the module at least partially abuts against the circumferential frame closest to the most upstream edge of the landing gear compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other objects, advantages and characteristics of the invention will become apparent on reading the following description of the invention, which is given by way of non-limiting example and with reference to the accompanying drawings, in which:

[0023] ● Figure 1 represents a schematic and simplified external side view of the front part of an aircraft according to the prior art;

[0024] ● Figure 2 A schematic and simplified lateral internal view showing the front part of an aircraft according to the invention, cut along a vertical longitudinal median plane;

[0025] ● Figure 3 According to the present invention Figure 2 Schematic and simplified lateral external views of the front part of three different series of aircraft of different embodiments of the embodiment represented in;

[0026] ● Figure 4 Indicates based on Figure 3 A schematic and simplified perspective view of a module of an embodiment of the present invention;

[0027] ● Figure 5 express Figure 4 A schematic and simplified side perspective view of a module of;

[0028] ● Figure 6 Indicates based on Figures 3 to 5 Schematic and simplified lateral interior view of the front part of the aircraft of an embodiment of the invention, cut along the vertical longitudinal mid-plane. DETAILED DESCRIPTION

[0029] The present invention relates to the construction of aircraft fuselages and more particularly to the construction of Figure 2 , Figure 3 ,and Figure 6The illustrated embodiment relates to the construction of the front part 12 of the fuselage. The terms front and rear refer to the displacement direction of the aircraft in flight ( Figure 2 In the following description, it is assumed that the aircraft is on a horizontal ground, so any plane at right angles to the ground is vertical.

[0030] Aircraft of known type are divided into sectors, each sector being formed by a portion of the fuselage delimited by two parallel transverse planes, which are vertical and parallel to the longitudinal direction of the aircraft (corresponding to the longitudinal direction of the aircraft). Figure 2 The segments are assembled to one another at two connecting segments which are located in the above-mentioned delimiting plane at the two free ends of the segment, with the exception of the front and rear parts which are provided with only one connecting segment.

[0031] The front part and the rear part have different forms that give the fuselage a gradual reduction in size until a zero-point section corresponding to the front and rear ends of the fuselage. In most cases, the middle part of the aircraft between the front part and the rear part has a substantially non-tapered form, for example in the form of an elliptical or cylindrical section. In some series, the middle part of the aircraft also has one or more parts with tapered sections. Thus, for example, in a sail wing or an aircraft with an integrated fuselage, the middle part is tapered. It should be noted that in the present description, for reasons of simplicity, the term aircraft covers sail wings and aircraft with an integrated fuselage. The front part and the rear part of the aircraft may also include one or more parts with substantially non-tapered sections.

[0032] During flight, at altitudes where the external pressure differs greatly from the pressure required by the people on board, it is necessary to maintain a determined pressure inside the aircraft. It is also important to protect the pilot and co-pilot from being hit by birds, stones or a variety of other types of objects. As a result, different stresses are applied to the front part of the aircraft, which complicate the design of the front part of the aircraft in order to ensure strength, rigidity and solidity while allowing a certain flexibility to absorb impacts. In addition, the openings formed in the fuselage for the insertion of the windows add additional difficulties. hereinafter throughout this description, the term window indicates the window of the cockpit. In most aircraft, a central window and a plurality of side windows are provided to ensure the viewing ability of the pilot and co-pilot from the cockpit. According to Figure 1In the example of an aircraft of , four side windows 14 are provided (only two windows are visible due to the side view). Due to the in-flight pressurization, the openings weaken the structure and the loads applied to the windows are significant. It is necessary to strengthen the structure at the periphery of the windows using specific frame members and reinforcements, the location and placement of which are conceived to optimize their number and weight. The design and construction of the area around the windows and the windshield are complex due to the stresses and forces present.

[0033] In aeronautics, a windshield is a generally accepted term that designates a panel extending from the window to the structural frame of the aircraft. The windshield exhibits a dome form to ensure good aerodynamic flow. The windshield (due to its positioning) must withstand the various stresses and forces stated above (such as, for example, bird strikes or various types of weather stresses) to protect the cockpit, and because of this, the windshield has a reinforced structure to resist the ingress of foreign objects.

[0034] The window frame provides the interface between the window and the fuselage of the cockpit, ie the link with the panels situated at the periphery of the window, which ensures its fixation in the face of all the stresses and forces mentioned above, such as for example all types of compression and impacts.

[0035] The present invention is to modularize this area of ​​the frame of the windshield and the window. By showing a single design form, the resulting module 16 is used for several aircraft and more widely for at least two fleets of aircraft of different series. In the description below, the term fleet indicates a group of at least two aircraft; this group is distinguished, for example, by the fact that it belongs to the same airline, or according to another example, this group is distinguished by being registered in the same country or any other feature that distinguishes it from another group. The term series has been defined above. Regardless of the aircraft of the fleet under consideration, the module 16 is exactly the same. The module forms a first section, the profile 18 of which corresponds to the profile of the second section 20, for direct assembly without any intermediate connecting section. The second section of each aircraft in the aircraft of the fleet under consideration has a form in which the profile of one of its free ends matches the module of the first section.

[0036] Figure 3Three nose cones 22, 24, 26 of different series of aircraft are shown. The outline 18 of the module 16 is shown, highlighting the modular aspect regardless of the series. It is clearly visible that the module 16 is identical among the three series of aircraft. On the other hand, the general form of the front part 22, 24, 26 is different from one series to another and is adapted to the outline 18 of the module. The outline 18 of the module corresponds to the outline 28 of the adjacent section for direct assembly with each other.

[0037] The modularity of the most structurally complex area to produce in the front part of the fuselage makes it possible to reduce development costs and maintenance costs. It also makes it possible to simplify the training of pilots, the modularity allowing them to find the same environment at least in part (and above all in terms of the windows that ensure the ability to see outside). Ultimately, this ensures the external visual signature of the aircraft for all the multiple fleets of the airline.

[0038] Figure 4 and Figure 5 Module 16 is shown separately. Module 16 surrounds the set of windows 30, 32, their frame members 34, and the wind deflector 36. To improve the outward viewing capability, only three windows are provided: the middle window 30 and two side windows (only one side window 32 is shown due to the side view).

[0039] exist Figure 2 and Figure 6 In the embodiment shown in FIG. 8 , the intermediate window 30 has a height such that the frame member 34 of the bottom edge 38 of the window 30 abuts the top portion of the sealed front bottom side 40 .

[0040] The aircraft has a generally vertical median plane of symmetry P (at Figure 4 ). A symmetry plane P divides the module into two parts. The front window is symmetrical with respect to plane P. The side windows (of which only window 32 is visible) are symmetrical with respect to plane P. The form of the actual module is symmetrical with respect to plane P.

[0041] exist Figures 2 to 6In the embodiment shown in the figure, the module 16 is produced by a single piece, a single complete panel 42. The panel 42 can be constructed by methods of known type by explosive forming or rolling. The reinforcement 44 is machined or added to the produced panel 42. The reinforcement 44 of the panel 42 can exhibit any type of geometry. In the embodiment shown, these reinforcements are arranged relative to each other according to a geometry different from the geometry of the reinforcement 46 used for the adjacent section: the reinforcement 44 of the module 16 has an at least partially isogrid structure, while the reinforcement 46 of the adjacent section 20 is positioned circumferentially. However, it is possible that the reinforcement of the adjacent section is positioned in any other way. The panel 42 is a complete panel, and the specific forces applied are as seen above, and the isogrid structure makes it possible to provide the desired strength and flexibility.

[0042] exist Figure 2 and Figure 4 In the embodiment shown in FIG. 1 , the module 16 has a top edge 48 in the form of an arc: the edge 48 follows the contour of the windshield front deflector 36. The top edge 48 of the module 16 is at least partially adjacent to the circumferential frame 54 closest to the most upstream edge of the landing gear compartment 56. The module 16 also comprises a bottom edge 50 in the form of an arc, which in the embodiment shown follows the contour of the front bottom side 40 of the seal. The end of the top edge 48 is connected to the end of the bottom edge 50 by a lateral straight edge 52, which provides the contour of the frame element of the aircraft window. The lateral edges 52 of the module are not horizontal, but inclined relative to the horizontal plane: relative to the horizontal plane, the edge descends from one end to the other end in the direction of the arrow V. In the embodiment shown, the lateral edges of the module start from the front bottom side 40 of the seal and rise in the example shown at least as far as the circumferential frame 54 closest to the most upstream edge of the landing gear compartment 56.

[0043] exist Figures 3 to 6In the embodiment shown in FIG. 1 , the front part 12 includes a cockpit escape hatch 58 in the top part of the fuselage above the front wind deflector 36. In this configuration, the form of the module 16 varies slightly. Likewise, the module 16 has a top edge 48 in the form of an arc: the edge 48 follows the contour of the front wind deflector 36. The module 16 also includes a bottom edge 50 in the form of an arc, which, in the embodiment shown, follows the contour of the front bottom side 40 of the seal. The end of the top edge 48 is connected to the end of the bottom edge 50 by a lateral straight edge 52, which provides the contour of the frame member of the aircraft window. The lateral edges 52 of the module are not horizontal, but are inclined relative to the horizontal plane: the lateral edges of the module start from the front bottom side 40 of the seal and rise at least in the example shown until the circumferential frame 54 closest to the most upstream edge of the landing gear compartment 56. A quadrilateral attachment 60 is provided symmetrically relative to the plane P on each side of the module 16. Each attachment 60 extends the module 16 from the top edge 48 to a frame 62 closest to the downstream edge of the top escape hatch 58. The lateral edges 52 of the module 16 are straight until the downstream end of the attachment 60: the bottom side of the attachment 60 forms part of the lateral edges 52 of the module 16. The top edge 48 of the attachment 60 is located above the windows 30, 32. The attachment 60 is located at Figure 3 and provide a single external characteristic marking for all aircraft of the family under consideration.

[0044] The example of the attachment 60 is given by way of illustration to show that the geometry of the windshield spoiler can be modified.

Claims

1. A method for constructing at least two fleets, said fleets having aircraft of different series, wherein: Each aircraft has a front part (12), said front part comprising windows (30, 32), frame members (34) of said windows, and a front windshield (36), and the general form of said front part differs from one series to another, characterised in that, for each aircraft, said method comprises: a step of constructing a module (16) consisting of the frame elements (34) of all the windows (30, 32) allowing viewing from the cockpit and the windshield (36), the form of the module being identical and consistent for all aircraft of different series in the fleet and not depending on the form of the fuselage of the aircraft, the module (16) being applicable to all aircraft of different series in the at least two fleets and being identical regardless of the aircraft of the at least two fleets; a step of constructing a contiguous section (20) of the fuselage, at least a portion of the edge (28) of said contiguous section being adapted to the contour of said module (16) and having a form identical to that of the edge of said module (16) so as to enable said module (16) to be directly assembled with said contiguous section (20) regardless of the aircraft of said at least two fleets, The module (16) includes an arc-shaped top edge (48) and an arc-shaped bottom edge (50), wherein the arc-shaped top edge (48) follows the contour of the windshield front fairing (36), and the arc-shaped bottom edge (50) follows the contour of the sealed front bottom side (40) of the aircraft, and when assembled, the arc-shaped top edge (48) is at least partially adjacent to the circumferential frame (54) closest to the upstream edge of the landing gear compartment (56) of the aircraft, and the arc-shaped bottom edge (50) is adjacent to the front bottom side (40).

2. The construction method according to claim 1, characterized in that: The step of constructing the module consists in producing the module as a complete panel (42) comprising a single piece and a single block.

3. The construction method according to claim 2, characterized in that: The complete panel (42) produced is formed by the frame members (34) and the wind deflector (36), and the module is reinforced in that the reinforcements (44) of the module (16) are arranged differently from the reinforcements (46) of the adjacent section (20).

4. The construction method according to claim 3, characterized in that: The reinforcements (44) of the modules (16) are arranged at least partially in an iso-grid manner on the modules (16) and at least partially circumferentially on the adjacent sections (20).

5. An aircraft fleet having aircraft of different series, wherein each aircraft has a front section including a window frame (34), windows (30, 32), and a windshield front deflector (36), and wherein: The general form of the front part varies from one series to another, characterised in that, for each aircraft, all the window frame elements (34) and the windshield front deflector (36) form a single-piece module (16), the form of the module being identical and consistent for all aircraft of the different series of the aircraft fleet and not dependent on the form of the fuselage of the aircraft, the module (16) being suitable for all aircraft of the different series of the aircraft fleet and being identical regardless of the aircraft of the aircraft fleet, the edge (18) of the module (16) forming a profile identical to the profile of the edge of the adjacent section to which the module is directly assembled, regardless of the aircraft of the different series of the aircraft fleet, The module (16) comprises an arc-shaped top edge (48) and an arc-shaped bottom edge (50), wherein the arc-shaped top edge (48) follows the contour of the windshield front fairing (36) and is at least partially adjacent to a circumferential frame (54) closest to the most upstream edge of a landing gear compartment (56) of the aircraft, and the arc-shaped bottom edge follows the contour of the sealed front bottom side (40) of the aircraft and is adjacent to the front bottom side (40).

6. The aircraft fleet according to claim 5, characterized in that: The module (16) comprises a one-piece and monolithic integral panel (42).

7. The aircraft fleet according to claim 6, characterized in that: The frame member (34) and the wind deflector (36) form a reinforced integral panel (42), wherein the reinforcements (44) of the module (16) are arranged differently from the reinforcements (46) of the adjacent section (20).

8. The aircraft fleet according to claim 7, characterized in that: The reinforcements (44) of the modules (16) are arranged at least partially in an iso-grid manner on the modules (16) and at least partially circumferentially on the adjacent sections (20).

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