阅读说明：本技术 可打开引擎罩组件和展开机构 (Openable hood assembly and deployment mechanism ) 是由 安托万·伊利·海勒瓜奇 昆廷·马蒂亚斯·艾曼纽尔·加诺德 马克·帕特里克·特斯尼尔 于 2018-12-18 设计创作，主要内容包括：本发明涉及飞行器推进单元整流罩的领域,更具体地说,涉及一种组件,其包括纵梁(31),所述纵梁(31)设置为安装在旁通涡轮喷气发动机(7)气体发生器(11)的横向构件上,所述纵梁平行于旁通涡轮喷气发动机(7)的纵向轴线(X),气体发生器(11)的整流罩(18)的可打开引擎罩(50),以及安装在纵梁(31)上从而在打开位置与关闭位置之间移动可打开引擎罩(50)的展开机构(60)。(The invention relates to the field of aircraft propulsion unit cowlings, and more particularly to an assembly comprising a longitudinal beam (31), said longitudinal beam (31) being arranged to be mounted on a cross member of a gas generator (11) of a bypass turbojet engine (7), said longitudinal beam being parallel to a longitudinal axis (X) of the bypass turbojet engine (7), an openable cowl (50) of a cowl (18) of the gas generator (11), and a deployment mechanism (60) mounted on the longitudinal beam (31) so as to move the openable cowl (50) between an open position and a closed position.)

1. An assembly, comprising:

longitudinal beam (31) arranged to be mounted transversely on the engine core (11) of a turbofan engine (7), parallel to the longitudinal axis (X) of said turbofan engine (7),

an openable hood (50) for a fairing (18) of the engine core (11), and

a deployment mechanism (60) mounted on the longitudinal beam (31) for moving the openable hood (50) between an open position and a closed position.

2. The assembly of claim 1, wherein the deployment mechanism (60) comprises a first pivot arm (61) extending between a first end (611) connected to the longitudinal beam (31) by a first hinge (612) and a second end (613) connected to the openable hood (50) by a second hinge (614).

3. The assembly of claim 2, wherein the deployment mechanism (60) further comprises a fixed rod (62) extending between a first end (621) and a second end (623), the first end (621) being connected to the pivot arm (61) between the first and second ends (611, 613) of the pivot arm (61) by a first joint (622), the second end (623) being connected to the openable hood (50) by a second joint (624).

4. The assembly as claimed in claim 3, wherein the first joint (622) and/or the second joint (624) of the fixation rod (62) is/are sliding.

5. Assembly according to claim 3 or 4, wherein the fixing rod (62) is telescopic.

6. Assembly according to any one of claims 2 to 5, further comprising a second pivoting arm (61), said second pivoting arm (61) being parallel to said first pivoting arm (61) and also extending between a first end (611) connected to said longitudinal beam (31) by a first hinge (612) and a second end (613) connected to said openable hood (50) by a second hinge (614) so as to form, together with said first pivoting arm (61), said longitudinal beam (31) and said openable hood (50), a deformable parallelogram.

7. An assembly according to any one of claims 2 to 6, further comprising a hood stay (63) releasably securable between the longitudinal beam (31) and the openable hood (50) in the open position.

8. Assembly according to any one of claims 2 to 7, wherein the first hinge (611) is slidably mounted on the longitudinal beam (31).

9. The assembly of claim 1, wherein the openable hood (50) is slidably mounted on the longitudinal beam (31).

10. The assembly according to claim 9, wherein the openable hood (50) slides parallel to a longitudinal axis of the turbofan engine (7).

Technical Field

The present invention relates to the field of cowlings for aircraft propulsion units, and more particularly to an assembly comprising an openable cowl of an engine core of a turbofan engine, and a deployment mechanism for moving the openable cowl between an open position and a closed position.

Background

In the prior art, deployment mechanisms mounted directly on the engine core casing have been proposed, for example in the publication of french patent application FR 2926790 a 1. However, this subjects the housing to additional mechanical forces that are preferably avoided.

To this end, among other assemblies, it has been proposed to connect the deployment mechanism to a suspension bracket supporting the propulsion unit, as disclosed for example in the publication of international patent application WO 2014/0911162a1, and in the publication of french patent application FR 2622930 a 1. However, this imposes additional constraints on the geometry, bulk, and in particular kinematics of the deployment mechanism, to avoid mechanical interference with the suspension pylon or with another openable hood.

Disclosure of Invention

The present invention aims to remedy these drawbacks by proposing an assembly comprising an openable hood for the cowling of the engine core of a turbofan engine and a deployment mechanism for moving said openable hood between an open position and a closed position, wherein said deployment mechanism can be simplified and risks mechanical interference with other elements of the nacelle of the turbofan engine.

According to a first aspect of the invention, to achieve this object, the assembly may further comprise a longitudinal beam configured to be mounted transversely on the engine core of the turbofan engine, oriented parallel to the longitudinal axis of the turbofan engine, and the deployment mechanism is configured to be mounted on the longitudinal beam.

Thanks to these arrangements, the deployment mechanism can be mounted in a stable manner on one side of the engine core, thus having the benefit of more space close to the support pylon of the turbofan engine.

According to a second aspect of the invention, the deployment mechanism may comprise a first pivot arm extending between a first end connected to the longitudinal beam by a first hinge and a second end connected to the openable hood by a second hinge. The deployment mechanism may also allow the openable hood to be opened by pivoting the first pivot arm to provide good access to the engine core, for example for inspection, maintenance and/or repair work to be performed there. Then, to ensure that the openable hood remains in the open position and/or the closed position, the deployment mechanism may further comprise a fixed rod extending between a first end and a second end, the first end being connected to the first and second ends of the pivot arm by a first joint and the second end being connected to the openable hood by a second joint. Thus, the securing lever may prevent pivoting of the pivot arm relative to the openable hood. To allow this sliding, the fixation rod may be telescopic and/or the first joint and/or the second joint of the fixation rod may be slidable. The deployment mechanism may then comprise at least one lock to prevent sliding of the sliding joint and/or telescoping of the fixed bar and thus relative pivoting of the pivot arm with respect to the openable hood.

The deployment mechanism may further comprise a second pivot arm parallel to the first pivot arm and further extending between a first end connected to the longitudinal beam by a first hinge and a second end connected to the openable hood by a second hinge, thereby forming a deformable parallelogram with the first pivot arm, the longitudinal beam and the openable hood and thereby maintaining the orientation of the openable hood relative to the longitudinal beam during opening and closing of the openable hood. Furthermore, by means of such a deformable parallelogram, the securing lever can not only prevent pivoting of the openable hood relative to the first pivot arm, but also by means of this can prevent the entire opening or closing movement of the openable hood.

The deployment mechanism may further include a hood stay releasably securable between the longitudinal beam and the openable hood in the open position to maintain separation thereof. Furthermore, the first hinge is slidably mounted on said longitudinal beam, so as to combine a lateral deviation and a longitudinal sliding during the opening and closing of the openable hood, and thus better access to the engine core.

Furthermore, according to a second aspect, the openable hood is slidably mounted on the longitudinal beam, in particular sliding parallel to the longitudinal axis of the turbofan engine.

Drawings

The invention will be well understood and its advantages will become more clearly apparent upon reading the following detailed description with the embodiments shown by way of non-limiting example. The specification refers to the accompanying drawings in which:

figure 1 is a schematic perspective view of an aircraft,

FIG.2 is a schematic longitudinal section of the turbofan engine of the aircraft of FIG.1,

FIG.3 is a side view of the structural assembly of the turbofan engine of FIG.2 connected to a receiving structure of the aircraft of FIG.1,

figure 4 is a front view of the structural assembly of figure 3,

figure 5 is a three-quarter rear perspective view of the structural assembly of figure 3,

figure 6 is a detailed view of the front mounting interface of the structural assembly of figure 3,

figure 7 is a detailed view of the rear mounting interface of the assembly of figure 3,

figure 8 is a detail view of the central suspension point of a variant of the structural assembly of figure 3,

figure 9 is a three-quarter rear perspective view of a variant of the assembly of figure 3,

FIG.10 is a schematic top view of a deployment mechanism staggered between the openable cowls of the engine core of the turbofan engine of FIG.2 and the longitudinal beams of the assembly of FIG.3, according to a first embodiment, with the openable cowls in a closed position,

FIG.11 is a schematic top view of the deployment mechanism of FIG.10, with the openable hood in an open position,

FIG.12 is a schematic rear view of the deployment mechanism of FIG.10, with the openable hood in an open position,

FIG.13 is a schematic rear view of a variant of the deployment mechanism of FIG.10, with the openable hood in the open position,

FIG.14 is a schematic top view of another variant of the deployment mechanism of FIG.10, with the openable hood in the open position,

figure 15 is a detailed view of the upstream seal of the openable hood of figure 10 in the closed position,

FIG.16 is a schematic top view of another variant of the deployment mechanism of FIG.10, with the openable hood in the open position,

FIG.17 is a schematic top view of a deployment mechanism according to a second embodiment, with the openable hood in a closed position,

FIG.18 is a schematic top view of the deployment mechanism of FIG.17, with the openable hood in an open position,

figure 19 is a schematic cross section of the deployment mechanism of figure 17,

FIG.20 is a schematic top view of a deployment mechanism according to a third embodiment, with the openable hood in the closed position,

FIG.21 is a schematic top view of the deployment mechanism of FIG.20, with the openable hood in an open position, an

Figure 22 is a schematic top view of the deployment mechanism of figure 20 with the openable hood in an intermediate position between the open and closed positions.

Detailed Description

Fig.1 shows an aircraft 1 comprising a fuselage 3, wings 4 and a tail 5, and two propulsion units 6 suspended below the wings 4 to respective receiving structures 2. Each receiving structure 2 can be fixed to a respective one of the two wings of the wing 4. Although in fig.1, which is a side view of the aircraft 1, it can be seen that a single wing of this wing 4 is together with its receiving structure 2 and its respective propulsion unit 4, the aircraft 1 may be substantially symmetrical with respect to the longitudinal and vertical planes, so that the other wing, together with the respective receiving structure and propulsion unit 6, is located on a hidden side of the aircraft 1 and is therefore not visible in this figure. In a manner known per se, each receiving structure comprises a suspension bracket fixed to the wing, for example by means of a joint fixed to at least one spar of the wing. However, the receiving structure may also comprise a structural casing of the wing, instead of or in addition to this type of suspension bracket.

Another identical or similar propulsion unit 6 is also suspended to the second wing on the other side of the aircraft, not visible in the figure. The two propulsion units 6 may each comprise a turbofan engine 7. As schematically shown in fig.2, this turbofan engine 7 may comprise a fan 10 and an engine core 11, said engine core 11 being formed by a low pressure compressor 12, a high pressure compressor 13, a combustion chamber 14, a high pressure turbine 15 connected to the high pressure compressor for the driving thereof, and a low pressure turbine 16 connected to the fan 10 and the low pressure compressor 12 for the driving thereof, and being aligned along a longitudinal axis X in the longitudinal direction, which may also serve as a thrust axis of the turbofan engine 7. In each of these two propulsion units 6, the fan 10 and the engine core 11 receive a respective cowling 17, 18.

In the aircraft 1 shown, the turbofan engine 7 may have a very high bypass ratio, for example greater than 5:1, 10:1, or even 15: 1. The diameter of the fan 10 is therefore particularly large to maintain sufficient ground clearance, since the aircraft 1 shown has low wings, the fan 10 being offset upwardly and forwardly relative to conventional structures. To achieve this offset, the fan 10 is not suspended to the receiving structure 2 fixed to the wing 4, but is held only by its structural connection to the engine core 11. Thus, as shown in fig.1, the structural assembly 20 connecting each turbofan engine 7 to the wing is not directly attached to the fan 10, but only to the engine core 11, wherein the fan 10 is therefore cantilevered with respect to this assembly 20.

Fig. 3-5 show one exemplary embodiment of the assembly 20. Thus, as seen in these figures, the structural assembly 20 may comprise a load-bearing structure 30 arranged to be applied to the engine core 11 and a suspension structure 40 connecting the load-bearing structure 30 to a receiving structure of the aircraft 1. More specifically, the load-bearing structure 30, which may be formed in particular in a single component, may comprise two longitudinal beams 31 and a transverse connecting member 32 rigidly connected thereto. In the shown embodiment the transverse connection element 32 has an arched shape, but other shapes for the transverse connection element 32 are conceivable, such as a closed loop in combination with two longitudinal beams or applied to them over 360 °, which further enhances the stiffness of the load-bearing structure 30 in the transverse plane. As in the embodiment shown, the two longitudinal beams 31 may each comprise at least one front mounting interface 33 and one rear mounting interface 34 for mounting the structure to the engine core 11, and a transverse suspension point 35 for connection with the suspension structure 40. As shown, these lateral suspension points 35 on the longitudinal beams 31 can be supplemented with central suspension points 36 on the lateral connecting members 32 for connection with the suspension structure 40.

As shown, each forward mounting interface 33 may be configured as an inter-compressor casing flange that is secured to a casing near the forward end of engine core 11, such as between low pressure compressor 12 and high pressure compressor 13, and transmits forces in the longitudinal direction as well as in a transverse plane perpendicular to longitudinal axis X. To this end, as shown in detail in fig.6, each front mounting interface 33 may comprise a plate 331 having a through opening 332 to receive a bolt to transmit longitudinal tension forces, and at least one lug 333 for transmitting transverse shear forces. These lateral forces may be lateral, i.e. parallel to the lateral axis Y, and may be vertical, i.e. parallel to the vertical axis Z.

On the other hand, each rear mounting interface 34 may be configured to be coupled to a housing, such as a turbine housing, near the rear end of engine core 11 that allows engine core 11 to be offset relative to the rear mounting interface 34 in both a longitudinal and transverse direction to accommodate thermal expansion of engine core 11 during operation. Thus, as shown in fig.7, each rear mounting interface 34 may include a slide plate 341 for receiving a slider 342, which slider 342 is mounted on a stud 343 fixed to engine core 11, for example, to the turbine casing of engine core 11, while allowing for the displacement of slider 342 in the longitudinal direction as well as in the transverse direction. In this way, the rear mounting interface 34 typically transmits only vertical forces to compensate for the longitudinal offset between the center of gravity G of the turbofan engine 7 and the front mounting interface 33.

Thus, when the carrying structure 30 is mounted on the engine core 11, the rear engine core 11 can be fixed between two longitudinal beams 31 parallel to the longitudinal axis X of the turbofan engine 7, so that they take up vertical bending moments, in particular those generated by the cantilever of the fan 10, thus relieving the casing of the engine core 11 of these forces.

Lateral suspension points 35 may be positioned on the rear end of the longitudinal beams 31 near the rear mounting interface 34 and arranged to transmit longitudinal and vertical forces. To this end, each lateral suspension point 35 may for example comprise an axle 351, which is received in a lateral direction in a respective opening in the suspension structure 40. As shown, when the structure is mounted on the center suspension point 36, the center suspension point 36 may be positioned centrally across the lateral attachment point 32 of the engine core 11. This central suspension point can then be directly suspended on the longitudinal axis X of the turbofan engine 7 and arranged to transmit vertical and lateral forces along a lateral plane. To this end, as shown, the central suspension point 36 may comprise an opening 361 arranged to receive the boom in the longitudinal direction. In a variant shown in detail in fig.8, the central suspension point 36 may also comprise a ball-and-socket joint 363 comprising a ball nut with an opening 361 formed therein, so that the suspension bar 362 may be angularly offset in the central suspension point 36, thus avoiding torque transmission through the central suspension point 36.

As shown in fig.3 to 5, the suspension structure 40 may comprise two suspension triangles 41, each arranged to be connected to one lateral suspension point 35 of the structure 30 via a low point 411 (fig. 5). As in the example shown, when the lateral suspension point 35 comprises an axis 351, a clevis 412 intended to receive said axis 351 can be formed in these low points 411 of the suspension triangle 41. Each suspension triangle 41 is oriented such that it can transmit the vertical and longitudinal forces it receives through the respective lateral suspension point 35 to the receiving structure 2. In order to limit their mass, each suspension triangle 41 may be formed by two bars 413 connected by a low point 411, as shown, although it is also possible to use a triangle 41' for each suspension triangle, as in the variant shown in fig. 9. As shown, by means of a joint 415 allowing at least an angular offset in the plane of the suspension triangle 41, each bar 413 of each suspension triangle 41 can be configured to be connected to an attachment point 414 on the receiving structure 2 by its end opposite the low point 411, thereby avoiding the transmission of bending moments between the receiving structure 2 and each bar 413. These joints 415 may also include ball and socket joints to allow for angular offset in other planes.

Furthermore, as shown, the suspension structure 40 may further comprise a suspension pyramid 42 arranged to connect the central suspension point 36 of the structure 30 to the receiving structure 2. To this end, the suspension pyramid 42 may include an apex 421 in which a suspension hanger 362 is formed, and four rods connected at the apex 421. More specifically, among the four rods, two upper rods 422 may be rigidly fixed to the vertex 421, extend towards respective attachment points 423 on the receiving structure 2, and are arranged to be connected to these attachment points 423 by means of a joint 424, so as to prevent the transfer of bending moments between each attachment point 423 and the respective upper rod 422 along the inclined surface. The suspension pyramid 42 can be completed by two lower bars 425, each connected by a joint 426, 427 corresponding to the apex 421 of the suspension pyramid 42 and to the low point 411 of the respective suspension triangle 41, thus maintaining the separation between the apex 421 of the pyramid 42 and the low point 411 of the suspension triangle 41. The geometry of the suspension structure 40 can thus be maintained even when the load bearing structure 30 is detached from the suspension structure 40.

As with each suspension triangle 41, the two upper bars 422 can also be replaced by a triangular plate 422 ', which triangular plate 422' is oriented along an inclined surface and is similarly connected to the apex 421 of the suspension pyramid 42 and to the attachment point 423 on the receiving structure 2, as shown in the variant shown in fig.9, in which elements identical to those of fig.5 have the same reference numerals. The aerodynamic effect of this type of plate 422 'on the air flow in the secondary flow can be controlled, for example, by perforating the plate 422', which can also reduce its mass. Even though in the shown variant the triangular plates 41 'and 422' each replace the hanging triangle 41 and the upper bar 422, it is equally feasible to replace only the upper bar 422 or one and/or the other of the two hanging triangles 41 in a hybrid hanging structure incorporating a bar and one or two triangular plates. Furthermore, one or the other of the plate 422 ', or the plate 41', may be used as a support for a surface heat exchanger, such as an air/air or air/oil exchanger.

In order to allow inspection, maintenance or repair work to be carried out on the engine core 11, its cowling 18 may include an openable hood 50. Each openable hood may be positioned transversely with respect to the engine core 11 and connected to a respective longitudinal beam 31 of the structure 30 by means of a deployment mechanism 60. According to a first embodiment shown in fig.10 to 12, the deployment mechanism may comprise a pivoting arm 61, said pivoting arm 61 extending between a first end 611 connected to the longitudinal beam 31 by a first hinge 612, the pivoting axis of which may in particular be vertical, and a second end 613 connected to the openable hood 50 by a second hinge 614, the pivoting axis of which may in particular be parallel to the pivoting axis of the first hinge 612. When the pivot axes of the first and second hinges 612, 614 are parallel, as shown, the pivot arm 61 may be formed by two parallel bars 615, 616, offset from each other along these pivot axes, as shown in fig. 12. However, as in the variant shown in fig.13, it is also possible that the pivot arm 61 can be formed in a single part with a certain width along the pivot axis.

To ensure that the openable hood 50 is maintained in the open position and/or the closed position, the deployment mechanism 60 may further comprise a fixed rod 62 extending between a first end 621 and a second end 623, the first end 621 being connected to the pivot arm 61 between the two ends 611, 613 of the pivot arm 61 by a first joint 622, the second end 623 being connected to the openable hood 50 by a second joint 624. To allow movement of the openable hood 50 between its open and closed positions, the first and/or second joints 622, 624 of the securing lever 62 may be mounted on the runner 625, as shown in fig. 10-12, and/or the securing lever 62 may be telescoping, as shown in fig. 14. The deployment mechanism 60 may then further include a lock (not shown) to lock the securing lever 62 when the openable hood 50 is in the open position and/or in the closed position.

Furthermore, in addition to or in lieu of the securing bar 62, the deployment mechanism 60 may further include a hood stay 63 releasably securable between the side rail 31 and the openable hood 50 in the open position to maintain the open position, and/or at least one locking member (not shown) to lock the openable hood 50 in the closed position, such as by retaining the openable hood 50 at an upper edge and/or a lower edge thereof, as shown in fig.12 and 14.

In order to ensure sealing of the openable hood 50 in the closed position and to suppress fire, at least one seal 53 may be provided on its periphery, in particular on its upstream edge. As shown in fig.15, the seal 53 may include a rib 531 projecting radially inward on an edge of the openable hood 50, and a groove 532 fixed to the engine core 11 and opening radially outward to receive the rib 531 when the openable hood 50 reaches the closed position. However, the structure may be reversed so that the rib is positioned on the engine core 11 and the recess is positioned on the openable hood 50. As shown, the groove 532 may specifically have a V-shaped cross-section.

In the variant shown in fig.16, the deployment mechanism 60 may comprise at least two parallel pivoting arms 61, offset from each other in the longitudinal direction, similarly connected to the longitudinal beam 31 and to the openable hood 50 so as to form, together with them, a deformable parallelogram so that the orientation of the openable hood 50 can be maintained during opening and closing.

In opening the openable hood 50 from the closed position shown in fig.10 with the deployment mechanism 60 according to this first embodiment, after unlocking the lock 64 and/or the fixing lever 62, at least one pivot arm 61 may first be pivoted in order to laterally separate the openable hood 50 from the engine core 11 while moving the openable hood 50 downstream, so as to reach the open position shown in fig.11, so that the engine core 11 is accessible for, for example, inspection, maintenance and/or repair work. Finally, the deployment mechanism 60 may be locked in this open position using the locking of the securing lever 62, and/or the hood stay 63 may be secured between the side rail 31 and the openable hood 50 to avoid premature closing. These steps may then be reversed to reclose the openable hood 50 by returning from the open position shown in fig.11 to the closed position shown in fig. 10.

According to a second embodiment shown in fig.17 to 19, the deployment mechanism 60 may comprise one or more sliding plates 65 fixed to the longitudinal beams 31, and one or more sliding blocks 66 fixed to the openable hood 50, instead of one or more pivoting arms, so that the openable hood 50 can be opened and closed by sliding the at least one sliding block 66 in the at least one sliding plate 65. In particular, as shown in fig.17 and 18, the slide plate 65 may be oriented in a longitudinal direction such that the openable hood 50 may slide longitudinally between its open and closed positions. As shown in fig.19, the deployment mechanism 60 may in particular comprise a first sliding plate 65 on the upper surface of the longitudinal beam 31 and a second sliding plate 65 on the lower surface of the longitudinal beam 31, each receiving at least two sliding blocks 66 connected to said openable hood 50 and offset from each other in the longitudinal direction.

In order to maintain the openable hood 50 in the open and/or closed position, the slide 65 may include at least one end-of-travel lock 651. Also, in order to facilitate the sliding of the slider 66, the slider 66 may be equipped with a pulley 661 capable of rolling on a rolling surface 652 in the slide 65, as shown in fig. 19. The other illustrated elements are equivalent to those of the first embodiment and they have the same reference numerals in figures 17 to 19 as in the previous figures.

During the opening of the openable bonnet 50 from the closed position shown in fig.17 with the deployment mechanism 60 according to this second embodiment, and after the at least one slider 66 has been unlocked, the openable bonnet 50 can be slid longitudinally in the downstream direction towards the open position shown in fig.18, so that the engine core 11 is accessible for inspection, maintenance and/or repair work, for example. Finally, deployment mechanism 60 may be locked in this open position to avoid premature closure. These steps can then be reversed to reclose the openable hood 50 by returning from the open position shown in fig.18 to the closed position shown in fig. 17.

To provide better access to the engine core, a pivoting arm may also be incorporated and slid as in the deployment mechanism 60 according to the third embodiment shown in fig.20 to 22. As shown, each slider 66 may then be connected to the openable hood 50 by a pivot arm 61, the pivot arm 61 extending between a first end 611 connected to the slider 66 by a first hinge 612 and a second end 613 connected to the openable hood 50 by a second hinge 614, the pivot axis of the first hinge 612 may in particular be vertical, and the pivot axis of the second hinge 614 may in particular be parallel to the pivot axis of the first hinge 612. In order to be able to hold the openable hood 50 in the open and/or closed position, the slide plate 65 may comprise at least one end-of-travel lock 651 and at least one of the hinges 612, 614 comprises a lock (not shown) as in the second embodiment described above, so as to releasably lock the angular offset of the at least one pivot arm 61. The other elements shown are equivalent to those of the first two embodiments and they have the same reference numerals in figures 17 to 19 as in the previous figures.

In opening the openable hood 50 from the closed position shown in fig.20 with the deployment mechanism 60 according to this third embodiment, at least one pivot arm 61 may first be pivoted after unlocking thereof to laterally separate the openable hood 50 from the engine core 11, thereby reaching the intermediate position shown in fig. 22. From this intermediate position and after having unlocked the at least one slider 66, the openable bonnet 50 can be slid longitudinally in the downstream direction towards the open position shown in fig.21 in order to access the engine core 11 for, for example, inspection, maintenance and/or repair work. Finally, deployment mechanism 60 may be locked in this open position to avoid premature closing. By returning from the open position shown in fig.21 to the closed position shown in fig.20 while passing again through the intermediate position shown in fig.22, these steps can then be reversed to reclose the openable hood 50.

Although the invention has been described by reference to specific examples and embodiments and specific variants, it is clear that different modifications and variations can be applied to these examples and variants thereof, without departing from the general scope of the invention as defined by the claims. For example, although only a single openable hood with a deployment mechanism on the side of the engine core has been described for each embodiment, it is naturally possible to have an openable hood of this type and a corresponding deployment mechanism on each side of the engine core. Furthermore, individual features of the different examples and embodiments mentioned and the different variants thereof may be combined in additional embodiments. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.