FR3109365A1 - One-piece frame door architecture - Google Patents

Abstract

Aircraft door comprising an outer skin (1) and an inner frame (2) which is in one piece and which comprises in one piece: - a peripheral frame (3) consisting continuously of a hollow section (16) which has a longitudinal opening which comprises an internal bearing tab (9) and an external bearing tab (8), extending along a surface conforming to the outer skin (1), on either side of the opening longitudinal (17), the outer skin (1) being fixed to the support legs (8,9) and closing the longitudinal opening of the peripheral frame (3); - reinforcing ribs (10) arranged in the peripheral frame (3) and each extending between two sections (5) of the peripheral frame (3). Figure for the abstract: Fig. 2

Description

One-piece frame door architecture

The invention relates to the field of aeronautics and relates to aircraft doors and their manufacturing methods. These doors are, for example, passenger boarding doors, emergency exit doors, cargo doors or any other opening intended to close the fuselage of an aircraft.

PRIOR ART

The manufacture of aircraft doors is generally complex and expensive given the constraints specific to the field of aeronautics. Passenger boarding doors, for example, are intended to close large openings in the aircraft fuselage. These doors must guarantee adequate mechanical strength at the level of the closed opening, as an extension of the structure of the aircraft. These doors must also guarantee a certain airtightness to maintain a high differential pressure during flight between the interior of the cabin and the exterior of the aircraft. These doors also embed many elements such as safety devices, control, guidance and locking mechanisms, or even finishing elements, which makes them heavy and complex assemblies.

A large majority of aircraft doors currently in service are manufactured by assembling many separate parts. Structural beams and reinforcing frames are assembled and fixed to an outer skin made from sheet metal or sheet material. Other functional elements are added to this set, such as stops for locking the door. Each element of the door is produced and checked separately and the assembly is then subject to meticulous assembly by the installation of fasteners such as rivets or screws.

For example, an airliner passenger boarding door is typically made of an assembly of around 150 parts and 1,500 fasteners.

These conventional manufacturing processes for aircraft doors make it possible to meet the safety criteria specific to aeronautics, in particular by the possibility of checking each of the parts and by the rigorous monitoring which is allowed in this type of industry during such a complex assembly. This is the reason why this type of assembly process and the corresponding doors are currently widely used in aeronautics.

However, these methods have the following disadvantages in particular:
- they require demanding means of implementation, in particular for positioning and wedging the parts for assembly with fasteners;
- the large number of operations involved in preparing for the installation of fasteners (drilling, countersinking, etc.) leads to as many possibilities of obtaining a non-conformity, which increases the scrap rate of a production;
- the installation of fasteners such as rivets is long and tedious, especially for internal parts and hard-to-reach corners;
- the mechanical connections at the level of the fixings are critical points for the mechanical properties of the assembly. In statics, phenomena of shearing of the fasteners and caulking of the fastening holes, relating to the passage of the forces at the level of these critical points, must be mitigated. In addition, the presence of the fixing holes has an adverse impact on the fatigue strength, which is linked to the presence of over-stresses which can initiate cracks. Aircraft doors having to meet high safety criteria, they are therefore subject to dimensioning, in particular at the level of the fixings, which increases the mass of the door.

These methods of the prior art are therefore long, expensive, and lead to aircraft doors whose mass would benefit from being reduced.

There are many attempts to improve the manufacture of aircraft doors although none have really taken hold so far.

For example, patent application US6817574 proposes casting a door in an aluminum or magnesium alloy in one piece, using a sand casting process. The forms of the door, and in particular its frame, have been adapted to such a process, in particular to allow the removal of the molding cores. The method described in this document solves a certain number of drawbacks mentioned above but nevertheless imposes a method which remains long and delicate by the number of operations which it imposes and which leads to aircraft doors which could be optimized from the point of view of mechanical characteristics and mass.

Furthermore, patent application US2007/0007390 describes an aircraft door made of a single piece which is entirely machined from a forged stock. Likewise, this document describes a method of manufacturing an aircraft door which solves a certain number of the drawbacks listed above but which however leads to an expensive method by the quantity of machining operations which it requires and leads to the production of a door requiring a large number of reinforcements at the level of its chord to have adequate rigidity.

The object of the invention is to improve the aircraft doors of the prior art.

To this end, the invention relates to an aircraft door comprising an outer skin and an inner chord, the chord being one-piece and comprising in one piece:
- a peripheral frame consisting continuously of a hollow profile which has a longitudinal opening and which comprises an internal support leg and an external support leg, the internal support leg and the external support leg extending on either side of the longitudinal opening, along a surface matching the outer skin, the outer skin being fixed to the support tabs and closing the longitudinal opening of the peripheral frame;
- Reinforcing ribs arranged in the peripheral frame and each extending between two sections of the peripheral frame.

According to another object, the invention relates to a method of manufacturing an aircraft door as described above, comprising the following steps:
- production of a forged blank of substantially constant thickness, from a stampable metal alloy;
- production of the one-piece chord by stamping the forged blank between a lower die and an upper die, the lower die comprising a punch for forming the hollow space of the hollow profile, and the upper die comprising an imprint for forming the external shape of the hollow profile;
- assembly of the one-piece chord with the outer skin by fixing the internal support leg and the outer support leg of the peripheral frame of the chord to the outer skin.

Such an aircraft door has a new architecture allowing greatly simplified manufacturing compared to the methods of the prior art, while guaranteeing the mechanical properties required for an aeronautical application.

The functions of maintaining a high differential pressure, rigidity, lightness, and reliability (relating in particular to fatigue resistance and crack propagation) are ensured in an optimal manner. However, this aircraft door only requires the assembly of two main elements: a one-piece frame and an outer skin.

The method according to the invention drastically reduces the number of operations necessary for the production of an aircraft door. Even compared to the alternative methods relating to the patent applications mentioned above, the method according to the invention also reduces the number of operations and leads to a manufacture at a lower cost.

In addition, the method according to the invention produces an aircraft door whose mechanical characteristics are improved. The static and fatigue behavior, as well as the rigidity of the door, are reinforced by the design in a single block forged for the chord. Die forging techniques allow an orientation of the fibers of the alloy which combine with this conformation.

The sizing of the elements of the aircraft door can thus be revised downwards, by limiting oversizing and by applying lower safety coefficients during the design.

In addition to the improved mechanical characteristics, the aircraft door is also lighter in a context where the reduction of the mass of the aircraft is strongly sought for fuel economy and the reduction of emissions.

Furthermore, the method according to the invention makes it possible to modulate the mechanical characteristics resulting from the forging, as precisely as needed.

The aircraft door according to the invention may comprise the following additional characteristics, alone or in combination:

- the hollow profile forms a loop around the periphery of the chord;

- the longitudinal opening of the peripheral frame extends continuously along the path of the hollow profile;

- The peripheral frame comprises door locking stops, projecting from the outer sides of the hollow profile;

- the locking stops each extend along a plane orthogonal to the hollow profile;

- Reinforcing ribs are extended, at each of their ends, in the hollow section by a web attached to a locking abutment;

- the internal support leg extends continuously over the entire internal circumference of the peripheral frame and the external support leg extends continuously over the entire external perimeter of the peripheral frame;

- each reinforcing rib has two attachment feet each arranged at one end of the reinforcing rib, each attachment foot being attached to the hollow section;

- the reinforcing ribs have a thinned central section between the two attachment feet;

- the reinforcing ribs are each shaped as a sheet of material extending along a plane orthogonal to the hollow section;

- the peripheral frame is shaped according to a substantially rectangular path, comprising two lateral end sections and two upper and lower end sections;

- the reinforcing ribs each extend from one lateral end section to the other lateral end section;

- the reinforcing ribs comprise plinths extending in continuity with the internal support leg, following a surface matching the outer skin;

- the frame further comprises intermediate ribs each extending between two reinforcing ribs;

- the intermediate ribs each comprise a base extending in continuity with the bases of the reinforcing ribs, following a surface matching the outer skin;

- the chord comprises through-openings between the reinforcing ribs, these through-openings being closed off by the outer skin;

- the chord has blanking panels between the reinforcing ribs, these blanking panels being placed against the outer skin.

The manufacturing process according to the invention may comprise the following additional characteristics, alone or in combination:

- the forged blank is substantially flat and is curved during the stamping step, according to the same curvature as the outer skin;

- the forged blank is pre-bent to the same curvature as the outer skin, before the stamping stage;

- the stamping step is carried out in several stamping operations carried out on different portions of the forged blank, by modifying the inclination of the forged blank between the stamping operations;

- during the stamping step, locking stops are formed on the outer contour of the peripheral frame, together with the hollow section.

PRESENTATION OF FIGURES

Other characteristics and advantages of the invention will emerge from the non-limiting description which follows, with reference to the appended drawings in which:

- FIG. 1 represents in perspective an aircraft door according to the invention;

- FIG. 2 represents the aircraft door of FIG. 1 in an exploded view;

- Figure 3 is a perspective and sectional view of the aircraft door of Figure 1;

- Figure 4 is a cross-sectional view of the door of Figure 1;

- Figure 5 is a partial view in vertical section of the door of Figure 1;

- Figure 6 is a schematic view of a stamping step of the method of manufacturing the door of Figure 1, in side view;

- Figure 7 is a schematic view of the stage of Figure 6, cross-sectional view;

- FIG. 8 represents in perspective the lower matrix of the method of FIGS. 6 and 7;

- Figure 9 illustrates the chord obtained by the methods of Figures 6 and 7;

- FIG. 10 illustrates a variant of the matrixing step;

- FIG. 11 schematically represents the stamped part obtained by the operation of FIG. 10;

- Figure 12 illustrates the chord obtained by the method of Figure 10;

- FIG. 13 is an exploded view of an aircraft door according to a second embodiment;

- Figure 14 is a perspective and sectional view of the door of Figure 13;

- Figure 15 is a cross-sectional view of the door of Figures 13 and 14.

DETAILED DESCRIPTION

FIG. 1 represents in perspective an aircraft door according to the invention, seen from its interior face, that is to say the face which is intended to be turned towards the cabin of the aircraft.

The expression “aircraft door” refers, throughout the description and the claims, to the assembly formed by an outer skin 1 and a chord 2. In addition to these elements, a conventional aircraft door comprises many other items of equipment attached to the frame 2 (locking and control mechanisms, safety and finishing elements, etc.) or to the outer skin 1 (hatch and portholes, for example). These additional elements are in accordance with the prior art and will not be described in more detail here.

The aircraft door consists of two main elements: a one-piece chord 2 (made from a single piece), and an outer panel forming the skin 1. In this example, the aircraft door is curved to fit the fuselage of the aircraft. The elements 1, 2 are assembled surface against surface along a curved joint surface.

Figure 2 illustrates the aircraft door in exploded view, showing the one-piece frame 2 and the skin 1 separated.

The skin 1 consists of a sheet of material whose thickness is generally of the order of half a centimeter. The skin 1 can be formed by any sheet of material suitable for aeronautics, such as a metal alloy sheet, or a panel made of composite material.

The frame 2 is a one-piece part which can also be made of any material suitable for aeronautics, such as a metal alloy or a composite material. The skin 1 and the frame 2 can be made from the same material, or from different materials. For example, the chord 2 can be made by stamping a metal alloy, while the skin 1 can be made of a composite material reinforced with carbon fibers.

The chord 2 comprises a peripheral frame 3 forming a continuous border around the entire periphery of the chord 2. The peripheral frame 3 is continuous, that is to say it surrounds the periphery of the chord 2 without interruptions, forming a closed loop. The shape of the peripheral frame 3, while remaining continuous, however, has changes in direction and shape. In this example, peripheral frame 3 defines four distinct sections:

- two sections of upper and lower ends 4 whose section is shown in Figure 5;

- two sections of lateral ends 5 whose section is illustrated in Figure 4.

The peripheral frame 3 defines a mechanical connection interface of the door with the structure of the fuselage of the aircraft. The two lateral end sections 5 are intended to cooperate with two lateral uprights of a door frame (not shown) fixed to the structure of the aircraft. Similarly, the two upper and lower end sections 4 come opposite horizontal rails of the door frame.

To ensure the locking of the aircraft door in the closed position, the door comprises locking stops 6 also made in one piece with the peripheral frame 3. In the present example, the door comprises twelve stops 6 distributed over the sections of side ends 5.

In this example, the locking abutments 6 include fixing holes 7 possibly making it possible to attach additional elements participating in the locking function, such as axles, locking shafts, or pads. These locking stops 6 allow the locking of the door in a conventional manner, by cooperating with complementary locking means provided on the door frame.

The peripheral frame 3 further comprises two support lugs 8, 9 extending on either side of the peripheral frame 3 over the entire circumference of the chord 2. The chord 2 is assembled on the skin 1 thanks to the fixing of these support tabs 8, 9 on the skin 1. The external support tab 8 and the internal support tab 9 extend along the same curved surface which follows the curvature of the skin 1 so that, when the frame 2 is assembled to the skin 1, the support legs 8, 9 are in surface contact over their entire length with the skin 1.

One of these support tabs is an external support tab 8 forming a continuous rim extending radially outwards from the frame 3 along a surface matching the surface of the skin 1. In the present example, the stops lock 6 are connected both to the profile of the peripheral frame 3 and to the external support leg 8.

The other support tab is an internal support tab 9 which forms an internal rim to the peripheral frame 3 and extends continuously over the internal periphery of the peripheral frame 3 by marrying the curved surface of the skin 1.

The frame 2 further comprises reinforcing ribs 10. These reinforcing ribs 10 extend transversely to the door, that is to say horizontally when the door is in its normal operating position (see Figure 1) and s extend perpendicularly to the two lateral end sections 5. Each reinforcing rib 10 directly connects one of the sections 5 to the other section 5.

The reinforcing ribs 10 are preferably arranged to connect two lateral end sections 5 at the level of a pair of locking stops 6 so that a force absorption is achieved by the arrangement of each stop 6 on either side the other with a reinforcing rib 10.

The reinforcing ribs 10 also have an optimized mass/rigidity ratio thanks to a shape having:
- An attachment foot 11 of maximum height, projecting from the peripheral frame 3 over its entire height, facing an abutment 6;
- a refined central portion 12, of less height, extending between the two attachment feet 11.

The reinforcing ribs 10 are shaped in the form of a sheet of material, that is to say their thickness is much less than their other dimensions, which in particular favors the manufacture by stamping described below. In the present example, the reinforcing ribs 10 have a thickness of the order of a centimeter for a width of the order of a meter.

Each reinforcing rib 10 is provided with a base 13 formed by a projecting fold perpendicular to the rib 10 at the same level as the internal support lug 9. The chord 2 is fixed to the skin 1 both by the lugs d support 8, 9 only by the bases 13 of the ribs 10. The bases 13 are attached in continuity of material with the internal support leg 9.

The fineness of the reinforcing ribs, the presence of the attachment feet, and their transverse attachment between two locking stops 6 guarantee mechanical characteristics in accordance with the use of the aircraft door, despite a low mass and the little elements required, further allowing optimized manufacturing.

In the present example, the aircraft door comprises a set of three reinforcing ribs 10 on the lower part of the door (with reference to the position of Figure 1) and a set of three reinforcing ribs 10 on its upper part. . Between these two sets of ribs 10, the door includes a central space for housing a porthole or other equipment. This central space is equipped, in this example, with two intermediate ribs 14 extending perpendicularly to two reinforcing ribs 10, and parallel to the two lateral end sections 5.

The intermediate ribs 14 are also shaped in the form of a sheet of material and also each comprise a base 15 projecting perpendicularly to the intermediate rib 14. The intermediate ribs 14 and their base 15 extend along a curved surface which follows the curvature of the the skin 1, at the same level as the bases 13 of the reinforcing ribs 10 and the internal support lug 9. The bases 15 are connected in continuity of material with the bases 13, at the same level.

When the frame 2 is assembled to the skin 1, all the contact surfaces on the two support legs 8, 9, the bases 13 and the bases 15 are located in a plane matching the shape of the outer panel and are therefore in contact surface with the skin 1.

Figures 3, 4 and 5, illustrate the different sections of the peripheral frame 3. Figure 3 is a cross-sectional view of the door of Figure 1, and Figure 4 is a two-dimensional view of the same section, illustrating the section of the peripheral frame 3 at the level of the lateral end sections 5. FIG. 5 is a view according to section V-V of FIG. 3 and illustrates the section of the peripheral frame 3 at the level of the upper end section 4 (the section end having the same section in this example).

Referring to Figures 4 and 5, the peripheral frame 3 is made over its entire path of a hollow profile 16 provided with an opening 17. The hollow profile 16 changes shape depending on the different sections 4, 5 but forms a frame continued. the locking stops 6 each extend along a plane orthogonal to the side of the hollow section 16. Each reinforcing rib 10 also extends along a plane orthogonal to the hollow section 16.

The opening 17 of the hollow profile 16 is seen in section in Figures 4 and 5, it being understood that this opening extends over the entire contour delimited by the peripheral frame 3. The interior of the hollow profile 16 is thus accessible by the opening 17 over the entire peripheral frame 3. The opening 17 extends longitudinally all along the peripheral frame 3, between the internal support tab 9 and the external support tab 8.

Referring to Figures 3 to 5, the skin 1 and the frame 2 are assembled so that the skin 1 closes the opening 17 over the entire peripheral frame 3.

According to an advantageous variant from the point of view of absorbing forces, each reinforcing rib 10 is extended inside the hollow part of the peripheral frame 3, until it is fixed against a stop 6. The ribs of reinforcement 10 are thus extended, at each of their ends, in the hollow profile 16 by a web attached to a locking abutment 6.

An example of a method for manufacturing the aircraft door of FIGS. 1 to 5 will now be described with reference to FIGS. 6 to 12. According to a particularly advantageous embodiment, the method comprises very few operations with in particular a step of manufacture of the chord 2 by stamping a metal alloy. Any forgeable alloy suitable for aeronautics can be used, for example aluminum alloys 7050, 7010, or 2050.

A first step of the method consists in obtaining by forging a blank 18 whose shape is substantially parallelepipedic. The forged blank 18 has a substantially constant thickness, that is to say it does not present sudden variations in thickness, although it can be prepared with a distribution of material adapted to the future forged part, with more thick in some areas.

Figures 6 and 7 schematically illustrate a second step of the process in which the forged blank 18 is stamped between an upper die 19 and a lower die 20. Figure 6 is a side view of the stamping operation (the blank 18 being seen in profile), while Figure 7 is a view corresponding to the section of Figure 4.

The stamping process makes it possible to obtain all the shapes constituting the chord 2 from the forged blank 18 in a single stamping step, which is permitted by the door architecture described above.

The upper die 19 includes indentations 21 intended to form the locking stops 6 (visible in figure 6), as well as an indentation 22 intended to form the external surface of the hollow profile 16 (visible in figure 7). The imprint 22 forms a closed loop in the matrix 19, following the shape of the peripheral frame 3.

In the view of Figure 6, the upper die 19 is seen in section along a plane passing through the six indentations 21 intended to form the locking stops 6 of one of the lateral end sections 5 of the door.

The side surfaces of the cavities 21 are preferably inclined, with respect to the stamping direction 25, by a draft angle, for example 7° (not visible in the schematic principle view of FIG. 6). The recess 22 can be dispensed with a clearance angle thanks to the shape of the profile 16 chosen here.

The lower die 20 also comprises a punch 23 intended for the formation of the cavity relating to the hollow character of the peripheral frame 3. The punch 23 is therefore a projecting form of the lower die 20 and forms a closed loop having, in this example, a substantially rectangular shape (although rounded at the corners) to define the hollow shape which extends continuously throughout the peripheral frame 3. Figure 8 illustrates in perspective the lower die 20 with the punch 23 protruding.

Figure 7 also shows recesses 24 located on either side of the recess 22, and intended to form the support legs 8, 9.

Indentations internal to the upper die 19 (not visible in the figures) are also intended to form the reinforcing ribs 10 and the intermediate ribs 14 with their respective bases 13, 15. The shape of the indentations hollowed out in the die 19 thus corresponds to all of the outer shapes of the chord 2 (as shown in Figure 2), in negative.

Referring to Figures 6 and 8, the upper and lower dies 19, 20 also have a curved shape along the same curvature as the finished door. In this simplified example, the door has a single curvature. Alternatively, the door may have two orthogonal curvatures.

Thus, the forged blank 18 is stamped in a single operation which results in a finished chord 2, including all of its shapes and its bending. The finished chord is shown schematically in Figure 9 in profile view. According to this embodiment, the locking abutments 6 extend in a direction parallel to the stamping direction 25, as do the reinforcing ribs 10 whose profile is visible in dotted lines.

As a variant, the cavities of the upper die 19, and in particular the cavities 21, can be dimensioned to form blocks of material amply encompassing the shapes to be produced, so that these shapes can be produced by complementary machining operations. This variant adds machining steps to the process but makes it possible to obtain shapes with an orientation independent of the stamping direction 25.

Once the chord 2 thus obtained by stamping, it can be assembled to the outer skin 1 which has been prepared by bending a sheet of material by any suitable means, or by producing it directly bent in the case for example of an embodiment in composite material.

FIGS. 10 to 12 illustrate a second embodiment of the stamping process in which the chord 2 is produced according to several stamping operations (two operations, in this example) on different portions of the forged blank 18. In FIGS. 10 to 12, elements similar to the first embodiment bear the same reference numbers in the figures.

According to this second embodiment, the forged blank 18 is produced and is then bent according to the curvature desired for the door. The stamping step then takes place in two stamping operations, separately for the upper half and for the lower half of chord 2 (in this example). The upper and lower qualifiers refer to the position of the door once mounted in the fuselage.

FIG. 10 illustrates a first stamping operation in which a first half of the forged blank 18 is stamped in a stamping direction 25 and which results in the part illustrated in FIG. 11. This part comprises a first forged half 26 which has all members of chord 2 on this half.

This first operation is then completed by a second stamping operation carried out in the same way but tilting and moving the forged blank 18, so as to present the other half to be forged between the dies 19, 20.

Figure 12 illustrates the chord obtained by this die-stamping in several die-stamping operations. The orientation of the elements such as the stops 6 or the reinforcing ribs 10 no longer depend on a single stamping direction 25 so that different sets of elements, stamped together, have a common orientation which may be different from other sets of elements that are matrixed in another matrixing operation. In this example, the locking stops 6 and the reinforcing ribs 10 extend perpendicular to a plane tangential to the chord, without requiring any machining operations.

As many stamping operations as necessary can be provided according to this second embodiment depending on the different orientations of the locking stops 6 and the reinforcing ribs 10 desired on different portions of the blank, stamped separately.

Figures 13 to 15 illustrate a second embodiment of the aircraft door architecture according to the invention. Referring to Figure 13, the door according to this second embodiment comprises an outer skin 1 having a central opening 27. The elements similar to the first and second embodiment of the aircraft door bear the same reference numbers to the figures.

Figures 14 and 15 illustrate the profile and arrangement of the assembly of the outer skin 1 and the chord 2, seen in section. The chord 2 comprises blanking panels 28 (shown schematically by cross-hatching in Figures 13 and 14) instead of the through openings 29 of the first embodiment (see Figure 1) which were closed by the outer skin 1.

The dimensions of the central opening 27 of the outer skin 1 are smaller are smaller than the dimensions of the space delimited by the inner contour of the inner support tab 9. The chord 2 is fixed to the outer skin 1 so that the support tabs 8, 9, and specifically the internal support tab 9, rest well on the outer skin 1, outside the central opening 27.

The central opening 27 is thus closed by the closing panels 28 of the frame 2 on the assembled door.

The exterior face of the aircraft door is therefore composed of a peripheral part formed of the outer skin 1 and of a central part formed of the closing panels 28 of the frame 2.

The aircraft door according to this second embodiment can also advantageously be produced by the manufacturing method described with reference to FIGS. 6 to 12, by simply adapting the imprints of the dies.

Alternative embodiments of the aircraft door and of its manufacturing method can be implemented without departing from the scope of the invention. In particular, the frame 2 and the outer skin 1 can be assembled by any means suitable for the materials used, such as gluing, welding, riveting.

Furthermore, the external 8 and internal 9 tabs can be discontinuous by being formed for example of tongues aligned along the path of the hollow section.

The die-stamping step can include, for the same die-stamping operation, one or more passes that are refined as you go.

Moreover, despite the possibility of producing the chord 2 in very few operations, the process can be supplemented by any machining operation making it possible to obtain specific final shapes or a desired surface condition.

Claims (22)

Aircraft door comprising an outer skin (1) and an inner chord (2), characterized in that the chord (2) is in one piece and comprises in one piece:
- a peripheral frame (3) consisting continuously of a hollow profile (16) which has a longitudinal opening (17) and which comprises an internal support leg (9) and an external support leg (8), the internal support tab (9) and the external support tab (8) extending on either side of the longitudinal opening (17), along a surface matching the outer skin (1), the outer skin (1) being fixed on the support tabs (8,9) and closing the longitudinal opening (17) of the peripheral frame (3);
- reinforcing ribs (10) arranged in the peripheral frame (3) and each extending between two sections (5) of the peripheral frame (3). Aircraft door according to Claim 1, characterized in that the hollow profile (16) forms a loop around the periphery of the frame (2). Aircraft door according to one of the preceding claims, characterized in that the longitudinal opening (17) of the peripheral frame (3) extends continuously along the path of the hollow section (16). Aircraft door according to one of the preceding claims, characterized in that the peripheral frame (3) comprises locking stops (6) of the door, projecting from the outer sides of the hollow section (16). Aircraft door according to Claim 4, characterized in that the locking stops (6) each extend along a plane orthogonal to the hollow section (16). Aircraft door according to one of Claims 4 or 5, characterized in that reinforcing ribs (10) are extended, at each of their ends, in the hollow profile (16) by a web attached to a locking abutment (6). Aircraft door according to one of the preceding claims, characterized in that the internal support lug (9) extends continuously over the entire internal periphery of the peripheral frame (3) and the external support lug (8 ) extends continuously over the entire outer circumference of the peripheral frame (3). Aircraft door according to one of the preceding claims, characterized in that each reinforcing rib (10) comprises two attachment legs (11) each disposed at one end of the reinforcing rib (10), each clip (11) being attached to the hollow section (16). Aircraft door according to Claim 8, characterized in that the reinforcing ribs (10) comprise a thinned central section (12) between the two attachment feet (11). Aircraft door according to one of the preceding claims, characterized in that the reinforcing ribs (10) are each shaped as a sheet of material extending along a plane orthogonal to the hollow section (16). Aircraft door according to one of the preceding claims, characterized in that the peripheral frame (3) is shaped according to a substantially rectangular path, comprising two lateral end sections (5) and two upper and lower end sections ( 4). Aircraft door according to Claim 11, characterized in that the reinforcing ribs each extend from one lateral end section (5) to the other lateral end section (5). Aircraft door according to one of the preceding claims, characterized in that the reinforcing ribs (10) comprise bases (13) extending in continuity with the internal support lug (9), along a surface hugging the skin exterior (1). Aircraft door according to one of the preceding claims, characterized in that the chord (2) further comprises intermediate ribs (14) each extending between two reinforcing ribs (10). Aircraft door according to Claim 14 when dependent on Claim 13, characterized in that the intermediate ribs (14) each comprise a base (15) extending in continuity with the bases (13) of the reinforcing ribs ( 10), following a surface matching the outer skin (1). Aircraft door according to one of the preceding claims, characterized in that the chord (2) comprises through-openings (29) between the reinforcing ribs (10), these through-openings (29) being closed off by the outer skin ( 1). Aircraft door according to one of Claims 1 to 15, characterized in that the chord (2) comprises blanking panels (28) between the reinforcing ribs (10), these blanking panels (28) being arranged against the outer skin (1). Method of manufacturing an aircraft door according to claims 1 to 17, characterized in that it comprises the following operations:
- Production of a forged blank (18) of substantially constant thickness, from a forging metal alloy;
- production of the one-piece chord (2) by stamping the forged blank (18) between a lower die (20) and an upper die (19), the lower die (20) comprising a punch (23) for forming the hollow space of the hollow profile (16), and the upper die (19) comprising an indentation (22) for forming the external shape of the hollow profile (16);
- assembly of the one-piece frame (2) with the outer skin (1) by fixing on the outer skin (1) the internal support leg (9) and the external support leg (8) of the peripheral frame (3) of the chord (2). Method according to Claim 18, characterized in that the forged blank (18) is substantially flat and is curved during the stamping step, according to the same curvature as the outer skin (1). Method according to Claim 18, characterized in that the forged blank (18) is pre-bent according to the same curvature as the outer skin (1), before the stamping step. Method according to Claim 20, characterized in that the stamping step is carried out in several stamping operations carried out on different portions of the forged blank (18), by modifying the inclination of the forged blank (18) between the matrixing operations. Method according to one of Claims 18 to 21, characterized in that, during the stamping step, locking stops (6) are formed on the outer contour of the peripheral frame (3), together with the hollow profile (16) .