Patent Publication Number: US-2015082708-A1

Title: Cover plate and door arrangement for a means of transportation

Description:
FIELD OF THE INVENTION 
     The invention pertains to a cover plate for covering a door clearance on a means of transportation, a door arrangement for a means of transportation, an aircraft with a cover plate or a door arrangement, as well as a method for closing a door. 
     BACKGROUND OF THE INVENTION 
     On an exterior of means of transportation, cover plates are frequently arranged in certain regions of a skin of the means of transportation for aerodynamic reasons, particularly in order to cover potential clearances, e.g., on doors or loading hatches. Such cover plates can be set in vibration due to air turbulences in a relative wind and thereby generate annoying noises. This may in turn be associated with increased aerodynamic drag and increased fuel consumption. 
     DE 10 2010 013 715 A1 and US 2011/02488514 A1 describe a door closing mechanism, as well as a method for closing a door of an aircraft. 
     DE 10 2011 085 269 A1 and US 2013/0105630 A1 describe a cover plate for a door clearance on an aircraft. 
     BRIEF SUMMARY OF THE INVENTION 
     An aspect of the invention may reduce annoying noises, aerodynamic drag and fuel consumption of a means of transportation, particularly of an aircraft. 
     One aspect of the invention concerns a cover plate for covering a door clearance between a skin of a means of transportation and a door. For example, the means of transportation may be an aircraft, a spacecraft, a train or a bus. The door may be a conventional door, but may also be, e.g., a hatch, a cargo hatch or a larger maintenance hatch on a skin of the means of transportation. 
     According to an embodiment of the invention, the cover plate comprises a mounting region for permanently fastening the cover plate on the door; a covering region for covering the door clearance; and a fastening device that is designed for fixing the covering region on the skin when the door is closed. In this context, the covering region and the mounting region of the cover plate may be interpreted as sections of the cover plate. The mounting region of the cover plate may be permanently and rigidly fastened on the door, e.g., by means of rivets, screws or adhesives. The cover plate may also form part of a door leaf of the door and be realized as one-piece with the door leaf. 
     An overall stability of the cover plate can be increased by fixing the mounting region of the cover plate on the skin of the means of transportation. This furthermore makes it possible to prevent the cover plate or the covering region of the cover plate from being set in vibration or fluttering due to a relative wind while the means of transportation is in motion. This can reduce the overall aerodynamic drag of the means of transportation and therefore result in fuel savings. 
     The door clearance can also be referred to as gap. 
     In an example, the cover plate is realized elastically and the covering region adjoins the skin when the door is closed. The covering region may therefore adjoin the skin with a tension as a kind of an elastic element when the door is closed. In other words, the cover plate may be tensioned due to its contact with the skin such that the covering region presses against the skin with a certain force and covers the door clearance. 
     According to an embodiment of the invention, the fastening device is designed for generating a force when the door is closed such that the covering region is pressed against the skin. The fastening device may hence serve for pressing the covering region against the skin with an additional force, i.e. a force in addition to the force that may be present due to the elastic tension of the cover plate, such that the covering region can no longer be lifted off and flutter, e.g. due to a relative wind. 
     According to another embodiment of the invention, additionally or alternatively, a door locking mechanism is provided for temporarily locking the door in a closed state urging the door against a door frame. The fastening device provides an additional fixation force for fixing the covering region on the skin when the door is closed at least during a state of moving condition of the means of transportation. 
     For example, the means of transportation is an aircraft and the fixation force is provided during flight of an aircraft, or also during takeoff and landing of an aircraft. 
     For example, the means of transportation is a train or bus and the fixation force is provided during driving condition of the train or bus with at least half of the normal travel speed, e.g. at a speed of over 40 km/h. 
     According to an embodiment of the invention, the covering region is provided with an abutting portion comprising an abutment surface for abutting the skin in an abutment direction when the door is closed. 
     According to an embodiment of the invention, the covering region is provided as a morphing structure deformable at least in the abutment direction. Further, the fastening device comprises a deformation contact surface provided on the covering region on a side of the abutment surface for a pressing abutment of an actuating element when the door is closed. Still further, the deformation contact surface is arranged on the covering region such that a pressing force in a direction opposite to the abutment direction leads to a deformation of the covering region such that the abutting portion is deformed in the abutment direction. 
     In an example, the morphing structure is provided as a buckling structure that buckles when the door is closed such that an increased abutment pressure of the cover plate&#39;s abutting portion is provided. 
     In another example, the actuating element is provided as a striker arrangement, or strike plate arrangement attached to a door frame arrangement. 
     In a further example, passive guide fittings are provided an at least one side portion for resting of the cover plate when closing the door to support the deformation of the deformation contact surface. 
     According to an embodiment of the invention, the fastening device comprises a bimetal arrangement provided in the covering region. The bimetal is configured such that a first degree of deformation is provided in a first temperature range and a second degree of deformation is provided in a second temperature range. The second degree of deformation is larger than the first degree of deformation in the abutment direction. The second temperature range relates to driving condition temperatures of the means of transportation, and the first temperature range relates to temperature conditions below the second temperature range. 
     In an example, the means of transportation is an aircraft and the first temperature range comprises ground temperature conditions and the second temperature range comprises cruising temperature conditions. 
     For example, the first temperature range, i.e. the ground temperature conditions, relates to a temperature of at least above −25° C., e.g. approximately −20° C. to approximately 60° C. air temperature. The second temperature range, i.e. the cruising temperature conditions, relates to a temperature of at least below −25° C., e.g. approximately −75° C. to approximately −30° C., e.g. approximately −50° C. to approximately −60° C., such as −56° C. The term approximately relates to a deviation of at least +/−2° C., such as +/−5° C. In case of an aircraft, the figures of the temperature range relate to air temperatures outside the aircraft&#39;s skin. 
     According to an embodiment of the invention, the fastening device comprises an engagement device for activating a movable component provided on the skin&#39;s edge of the clearance. The engagement device is provided for causing the movable component to move towards the door, thus covering the clearance. 
     According to an embodiment of the invention, the fastening device comprises an active engagement device for engaging behind an edge of the skin to pull the cover plate towards the skin such that an abutment force of the abutment surface is increased. 
     According to an embodiment of the invention, the door cover plate comprises a pneumatic sealing device that has a locking edge. Further, the pneumatic sealing device is deflated in an open state of the door, and inflated when the door is closed such that the locking edge acts as the engagement device. 
     In case of an aircraft, the following examples are provided. In an example, the pneumatic sealing is be inflated by pressurized air provided for example by the cabin air pressure or by additional air supply such as from a high-pressure air tank or engine bleed air. In another example, the pneumatic sealing is provided with a closed air volume that expands due to lower air pressure in higher altitudes. For example, the pneumatic sealing is set such that the expansion starts in an altitude above approximately 5.000 meter above sea-level. In a further example, the pneumatic sealing is inflated by dynamic pressure generated via an NACA inlet, for example, when the means of transportation starts to move. 
     According to an embodiment of the invention, the fastening device comprises an engagement arrangement with a plurality of clamping pairs each comprising a first and a second clamping component provided on the cover plate and the skin respectively. The first and second clamping components each comprise at least one engaging portion to engage with an engaging portion of the other of the second and first clamping component. The engaging portion engage behind each other in a direction transverse to the skin&#39;s surface. The engaging portions engage with each other when the door is closed in a closing movement direction in a sliding manner such that the cover plate and the skin are urged against each other in a direction transverse to the closing movement direction. 
     In an example, the engaging portions are provided as hook and pile fastener with a plurality of mushroom like protrusions to provide the engagement. 
     In an example, the clamping pairs are provided with inclined engagement sections that are provided to engage with each other when the door is closed in a closing movement direction in a sliding manner such that the cover plate and the skin are urged against each other in a direction transverse to the closing movement direction. 
     In an example, the clamping pairs are provided as dovetail locking pairs comprising engagement surfaces that are at least inclined in relation to the abutment surface. In a further example, the engagement surfaces are also arranged in an inclined manner in relation to a transverse door closing movement, i.e. a movement of the door in the plane of the skin. For example, the transverse door closing movement may be provided as a sliding movement of the door, for example in a vertical or horizontal direction. 
     According to an embodiment of the invention, the fastening device comprises a deploying edge of the cover plate that extends when the door is closed to rest against a guide edge of the skin. An activating element is provided for deploying the deploying edge. The activating element is activated by the closing movement of the door when the door is closed. 
     In an example, the deploying edge is provided as an elevating flap extendable in the plane of the door. A guide member is provided on the edge of the skin such that the elevating flap can extend until its edge is abutting the guide member to effectively closing, i.e. covering the door clearance. The guiding member can be formed integrally with the adjacent skin. 
     In an example, the guide member and the edge of the elevating flap are provided with complementary inclined edges that are inclined with respect to a direction perpendicular to the adjacent skin, for example the aircraft outer skin of the fuselage structure. 
     In another example, the edge of the elevating flap is provided with a stepped protrusion comprising a protruding portion that, in the closed state, overlaps the guiding member on a back side. 
     In an example, the activating element is de-activated at least by an opening movement of the door when the door is opened. For example, the de-activation is caused when a door locking mechanism is released, e.g. before the actual opening movement occurs. 
     In an example, the deploying edge and the guide edge are provided with matching inclined abutment surface portions. 
     In another example, the deploying edge has an engaging portion to engage behind the guide edge. 
     According to an embodiment of the invention, the fastening device features at least one hook element that is arranged on a side of the cover plate or the covering region facing the skin, wherein the at least one hook element is designed for engaging into at least one corresponding hook element that is arranged on the side of the skin facing the cover plate or the covering region in order to fix the cover plate on the skin when the door is closed. For example, the hook elements on the cover plate and on the skin may be realized complementary to one another such that they generate a force, which pulls the cover plate or the covering region in the direction of the skin and thereby fixes the cover plate or the covering region, when they engage into one another in the closed state of the door. Mechanical fixing of this type for the cover plate by hook elements can be realized in a very stable and robust fashion. Such a solution can further be inexpensively implemented, as well as realized such that it requires little maintenance and functions reliably, because no electric and/or electronic components whatsoever are required. 
     In an example, the door is designed for locking in the door frame with a transverse motion in the door frame during closing of the door. The hook elements are realized in such a way that they engage into one another during the transverse motion. 
     According to an embodiment of the invention, the cover plate comprises a magnetically active layer that is arranged at least in a section of the cover plate on its side that faces the skin and designed for being pulled in the direction of the skin by a magnetic element. For example, the magnetically active layer may be arranged on a section of the covering region, on the entire covering region or even on the entire side of the cover plate that faces the skin. In this context, “magnetically active” may be interpreted as magnetisable and/or magnetized such that the magnetically active layer can be subjected to a magnetic force in a magnetic field. 
     In an example, the magnetically active layer of the cover plate is a magnetically active film or a magnetically active plate. For example, the film or the plate may be permanently connected to the cover plate, e.g. by means of rivets, screws or adhesives. However, the entire cover plate may also be made of a magnetically active material. 
     In an example, the at least one magnetic element comprises at least one electromagnet and the at least one electromagnet is coupled to a locking mechanism of the door such that the cover plate is automatically fixed on the skin by the at least one electromagnet when the door is locked. 
     In an example, the cover plate features a fibre-reinforced composite material. A fibre-reinforced composite material can be advantageously utilized as material for the cover plate, in particular, due to its lightness and flexibility, as well as its stability. 
     Another aspect of the invention concerns a door arrangement for a means of transportation. 
     According to an embodiment of the invention, the door arrangement comprises a door frame, a door and a cover plate according to one of the examples described above and below that is fastened on the door, e.g. as described above and below. The cover plate or the mounting region of the cover plate may be fastened, for example, on an upper end and/or on the sides of the door. 
     In an example, at least one first hook element is provided on the cover plate, and at least one second hook element is provided on the skin of the means of transportation for fixing the cover plate on a skin, and designed for engaging into the first hook element when the door is closed such that the cover plate is fixed on the skin. The at least one first hook element protrudes from the cover plate at least in a section. The at least one second hook element further comprises a first region that is fastened on the skin, a second region that protrudes from the skin, and a third region that is realized correspondent to the at least one first hook element. 
     In an example, the door arrangement comprises at least one first hook element on the mounting region of the cover plate; and at least one second hook element on the skin of the means of transportation serving for fixing the cover plate on the skin and designed for engaging into the first hook element when the door is closed and to thereby fix the cover plate on the skin. In this case, the at least one first hook element may be arranged on a side of the cover plate that faces the skin and the at least one second hook element may be arranged on a side of the skin that faces the cover plate. The at least one first hook element protrudes from the cover plate at least in one section. The at least one second hook element comprises a first region that is fastened on the skin, a second region that protrudes from the skin and a third region that is realized correspondent and/or complementary to the at least one first hook element such that the hook elements can engage into one another. 
     In an example, the door is designed for locking in the door frame with a transverse motion during closing, wherein the hook elements are realized and/or arranged in such a way that they engage into one another during this transverse motion. In this context, a transverse motion can be interpreted as a motion of the door within the door frame that takes place transverse to a surface of the door. This transverse motion therefore may be a lateral motion, i.e. a motion transverse to the laterally extending parts of the door frame. However, the transverse motion may also be a downward motion or upward motion within the door frame. In any case, the transverse motion may essentially take place orthogonal to a normal vector on a surface of the skin. 
     In an example, the door arrangement comprises a magnetically active layer on at least a section of a side of the cover plate that faces the skin, and at least one magnetic element that is arranged on a side of the skin that faces away from the cover plate. In this case, the magnetic element may be arranged in a region of the skin that is covered by the cover plate when the door is closed. The at least one magnetic element is designed for pulling the cover plate in the direction of the skin with a magnetic force that can act upon the magnetically active layer when the door is closed such that the cover plate is magnetically fixed on the skin. 
     In this case, the magnetically active layer may also be arranged, for example, on a section of the covering region, on the entire covering region or on the entire side of the cover plate that faces the skin. In this context, “magnetically active” can be interpreted as magnetisable and/or magnetized such that the magnetically active layer can be subjected to a magnetic force in a magnetic field. 
     In an example, the at least one magnetic element comprises at least one electromagnet, and the at least one electromagnet is coupled to a locking mechanism of the door such that the cover plate is automatically fixed on the skin by the at least one electromagnet when the door is locked. In this context, “coupling” can be interpreted as “driving” and/or “activating” and/or “actuating.” For example, the coupling of the electromagnet to the locking mechanism of the door may reduce the number of manipulations required for definitively closing the door and an actuation of the magnetic element or the electromagnet cannot be inadvertently forgotten. 
     Another aspect of the invention concerns an aircraft with a cover plate of the type described above and below and/or a door arrangement of the type described above and below. For example, the aircraft may be a passenger aircraft or a cargo aircraft. 
     In a further example, for the cover plate, combinations of the above described examples of the cover plate are provided. For example, at least two of the group of the deformable morphing structure, the bimetal arrangement, the engagement device, the active engagement device, the pneumatic sealing device, the plurality of clamping pairs, the deploying edge, the at least one hook element and the magnetically active layer are provided. 
     In an example it is provided a combination of the deformable morphing structure with the bimetal arrangement, or the deformable morphing structure with the engagement device, or the engagement device with the active engagement device and/or with the pneumatic sealing device, or the plurality of clamping pairs with the deploying edge, or the at least one hook element with the magnetically active layer, or the bimetal arrangement with the engagement device, or the pneumatic sealing device with the plurality of clamping pairs. 
     In a still further example, the door arrangement is provided with one of these combinations for the cover plate. 
     Another aspect of the invention concerns a method for closing a door of a means of transportation, with said method comprising the steps of: 
     a) moving the door in the direction of a skin of the means of transportation in a door frame;
 
b) covering a door clearance between the skin of the means of transportation and the door with a cover plate; and
 
c) fixing the cover plate on the skin with a fastening device on the cover plate.
 
     As described above and below, the cover plate may in this case be fastened on the door with a mounting region and may comprise a covering region that is designed for covering the door clearance. 
     In an example, the method further comprises the steps of: 
     d) locking the door in the door frame by means of a transverse motion; and
 
e) fixing the cover plate by means of hook elements on the cover plate and the skin.
 
     In this case, the hook elements are realized in such a way that they engage into one another during the transverse motion and thereby fix the cover plate on the skin. 
     For example, several hook elements may be provided on a side of the skin that faces the cover plate and additional hook elements may be provided on a side of the cover plate that faces the skin. 
     In further examples of the method, the door clearance is covered by a cover plate according to one of the examples described above. 
     Exemplary embodiments of the invention are described in greater detail below with reference to the attached figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  schematically shows a means of transportation with a conventional cover plate and door arrangement. 
         FIG. 1B  schematically shows a section through the cover plate and the door arrangement in  FIG. 1A  along a centre plane. 
         FIG. 1C  schematically shows another conventional cover plate and door arrangement of a means of transportation. 
         FIG. 1D  schematically shows a detail view of the cover plate of  FIG. 1C . 
         FIG. 2A  schematically shows a cover plate and a door arrangement according to a potential embodiment of the invention. 
         FIG. 2B  schematically shows a section through the cover plate and the door arrangement of  FIG. 2A  along a centre plane. 
         FIG. 2C  schematically shows a section through a fastening device of the cover plate of  FIG. 2A  along a plane. 
         FIG. 3A  schematically shows a cover plate and a door arrangement according to another potential embodiment of the invention. 
         FIG. 3B  schematically shows a section through the cover plate and the door arrangement of  FIG. 3A  along a centre plane. 
         FIG. 3C  schematically shows another example of a section through the cover plate and the door arrangement. 
         FIG. 4A  schematically shows a cover plate and a door arrangement according to an embodiment of the invention. 
         FIG. 4B  schematically shows a section through the cover plate and the door arrangement of  FIG. 4A  along a centre plane. 
         FIG. 4C  schematically shows details of the cover plate of  FIG. 4B . 
         FIG. 5  shows a section through a door arrangement and a cover plate according to an embodiment of the invention. 
         FIGS. 6A-6D  show a further embodiment for a cover plate comprising a morphing structure, wherein  FIG. 6A  shows a schematic outside view when a door is slightly opened,  FIG. 6B  shows a schematic cross-section when the door is slightly opened,  FIG. 6C  shows an outside view when the door is closed, and  FIG. 6D  shows a schematic cross-section when the door is closed. 
         FIG. 7  shows another embodiment of a cover plate comprising a bimetal cover plate in a schematic cross-section. 
         FIGS. 8A-8C  show a further embodiment of a cover plate comprising a guided hinged flap, wherein  FIG. 8A  shows an open position,  FIG. 8B  shows a door in a slightly open state and  FIG. 8C  shows the door closed in a schematic cross-section. 
         FIG. 9  shows a schematic cross-section through a cover plate comprising an engagement connection with a mushroom-like snap connection. 
         FIGS. 10A-10B  show an embodiment of a cover plate with a clamp, wherein  FIG. 10A  shows a schematic cross-section of a disengaged clamp, and  FIG. 10B  shows an engaged clamp. 
         FIG. 11  shows an embodiment with a latch lock mechanism in a schematic cross-section. 
         FIG. 12  shows an embodiment with a latch lock mechanism. 
         FIGS. 13A-13D  show an embodiment with a pneumatic inflatable seal, wherein  FIG. 13A  shows a schematic cross-section in an open position,  FIG. 13B  shows a slightly opened door,  FIG. 13C  shows a closed door, and  FIG. 13D  shows a closed door position with a pressurized seal. 
         FIGS. 14A-14D  show an embodiment with an elevating flap, wherein  FIG. 14A  shows a cross-section of an open position,  FIG. 14B  shows a first contact of the elevating flap, and  FIG. 14C  shows a door in a closed position, and  FIG. 14D  shows a further embodiment of an elevating flap. 
         FIGS. 15A-15D  show an embodiment with engagement connection, wherein  FIG. 15A  shows an outside view indicating a dovetail locking system, and  FIG. 15B  shows the dovetail locking system of  FIG. 15A  in a closed position, and  FIG. 15C  shows a schematic cross-section of the dovetail locking system with a slightly opened door, and  FIG. 15D  shows a dovetail locking system in a schematic cross-section with a closed door. 
         FIG. 16  shows an aircraft with a door arrangement and a cover plate according to an embodiment of the invention. 
         FIG. 17  shows a flow chart that illustrates the steps of a method for closing a door on a means of transportation according to an embodiment of the invention. 
     
    
    
     Identical or similar components are basically identified by the same reference symbols. 
     DETAILED DESCRIPTION 
     The illustrations in the figures are merely schematic and not true-to-scale. 
       FIG. 1A  schematically shows a means of transportation  100  with a conventional cover plate  10   a  and a conventional door arrangement  12 , wherein the means of transportation  100  may, for example, be an aircraft. 
     The door arrangement  12  comprises a door  14  that is arranged in a door frame  16  in a skin  18  of the means of transportation  100 . The cover plate  10   a  of the door arrangement  12  is arranged on an outer side of the door  14  in an upper region  15  of the door  14  and covers the door  14  and the door frame  16  in the upper region  15 , as well as part on the sides of the door  14  and the door frame  16 . 
     The cover plate  10   a  further covers a door clearance  20  between the skin  18  and the door  14  in the upper region  15 . 
     When the means of transportation  100  is in motion, a comparatively strong relative wind  21  can occasionally occur as indicated with the arrow  21  in  FIG. 1A . The relative wind  21  may cause the cover plate  10   a  to be lifted off the skin  18  and to begin to flutter. This may in turn be associated with annoying noises. 
     This is elucidated in greater detail with reference to a section through the cover plate and the door arrangement in  FIG. 1A  along a central plane A-A which is schematically illustrated in  FIG. 1B , wherein the viewing direction of the section shown extends toward the right in the plane of projection of  FIG. 1A . 
       FIG. 1B  clearly shows the clearance  20  between the skin  18  and the door  14 , which clearance is covered with the cover plate  10   a . In this case, the cover plate  10   a  has a mounting region  11   a  that is fastened on the door  14  and a covering region  11   b  that covers the clearance  20 . The mounting region  11   a  may be fastened on the door  14 , for example, by rivets, screws, bonding or welding. All in all, the cover plate  10   a  may be realized elastically, wherein the covering region  11   b  may adjoin the skin  18  with tension. 
     The relative wind  21  may cause the covering region  11   b  to be lifted off the skin  18  and to begin vibrating or fluttering. This vibrating or fluttering is respectively indicated with the arrow  23  in  FIG. 1B . 
       FIG. 1C  schematically shows a further conventional cover plate  10   a  and door arrangement  12  of a means of transportation  100 , and  FIG. 1D  schematically shows a detail of the cover plate  10   a  in  FIG. 1C . If not indicated otherwise, the cover plate  10   a  and the door arrangement  12  may in this case comprise the same components as the cover plate  10   a  and the door arrangement  12  in  FIG. 1A  and  FIG. 1B . 
     In  FIG. 1C  and  FIG. 1D , the mounting region  11   a  of the cover plate  10   a  is fastened on the door  14  with rivets  17  and covers the upper region  15  of the door arrangement  12 , part of the door  14 , part of the door frame  16  and the clearance  20  between the skin  18  of the means of transportation  100  and the door  14 . 
       FIG. 2A  schematically shows a cover plate  10  and a door arrangement  12  according to a further embodiment. If not indicated otherwise, the cover plate  10  and the door arrangement  12  in  FIG. 2A  may comprise the same components as the cover plate  10   a  and the door arrangement  12  in  FIG. 1A . 
     Fastening devices  22  are arranged on the covering region  11   b  of the cover plate  10  and designed for respectively fixing the cover plate  10  or the covering region  11   b  on the skin  18 . 
     In this case, the fastening devices  22  may protrude from the cover plate  10 , e.g. in the form of air outlets  27 . These air outlets  27  may feature a closed region  29  on one side and an open region or an opening  31  on an opposite side. The closed region is directed against the relative wind  21  in this case. The fastening device  22  may further comprise a peripheral seal  23  that radially extends around the covering region  11   b . For example, the seal  23  may be made of silicone, e.g. in the form of a sealing lip, and arranged on a side of the covering region  11   b  that faces the skin  18 . 
     When the relative wind  21  passes over the air outlets  27 , air is evacuated from the intermediate space between the covering region  11   b  and the skin  18  through the openings  31  such that a negative pressure zone  25  can be created between covering region  11   b  and skin  18 . The seal  23  makes it possible to prevent air from respectively flowing underneath the covering region  11   b  or into the negative pressure zone  25  from an edge region of the cover plate  10 . All in all, the pressure differential between an outer region with high pressure and the negative pressure zone  25  with low pressure makes it possible to generate a contact pressure that is directed toward the skin  18  and that can fix the covering region  11   b  of the cover plate  10  on the skin  18 . This can prevent the covering region  11   b  from being lifted off the skin  18  and the cover plate  10  from fluttering. 
       FIG. 2B  schematically shows a section through the cover plate  10  and the door arrangement  12  in  FIG. 2A  along a central plane A-A, wherein this figure clearly shows that the peripheral seal  23  adjoins the skin  18  above the door clearance  20  such that the negative pressure zone  25  can be created and a pressure compensation via the edge of the cover plate  10  can be prevented. 
       FIG. 2C  schematically shows a section through an air outlet  27  of the fastening device  22  of the cover plate  10  in  FIG. 2A . 
       FIG. 2C  illustrates how air is evacuated from the intermediate space between the covering region  11   b  of the cover plate  10  and the skin by the relative wind  21  through the opening  31  of the air outlet  27 . This is indicated with the arrow  33  in  FIG. 2C . 
       FIG. 3A  schematically shows a cover plate  10  and a door arrangement  12  according to a further potential embodiment. If not indicated otherwise, the cover plate  10  and the door arrangement  12  in  FIG. 3A  may comprise the same components as the cover plate  10   a  and the door arrangement  12  in  FIG. 1A . 
     In the door arrangement  12  illustrated in  FIG. 3A , a spoiler  35  is arranged on the skin  18  above the covering region  11   b  of the cover plate  10 . The spoiler  35  may be made, e.g., of aluminium, steel or a fibre-reinforced composite material and fastened on the skin  18  by adhesives, rivets or screws. 
     For example, the spoiler  35  may protrude from the skin  18  and extend above the cover plate  10  in a U-shaped fashion. The spoiler  35  may be designed for generating air turbulences around the cover plate  10 . In other words, the spoiler  35  may be designed for disturbing an air flow around the cover plate  10  caused by the relative wind  21 . These turbulences make it possible, for example, to prevent a directional air flow from being admitted between the covering region  11   b  and the skin  18  such that the covering region  11   b  is not lifted off by the air flow and therefore can no longer flutter. 
       FIG. 3B  schematically shows a section through the cover plate  10  and the door arrangement  12  in  FIG. 3A  along a centre plane A-A, wherein a lateral profile of the spoiler  35  is illustrated in this figure. For example, the spoiler  35  may adjoin the skin in a relatively flat fashion with a first region  35   a  and protrude from the skin  18  in a second region  35   b  that may border on the covering region  11   b  of the cover plate  10  such that the air flow can be respectively disturbed in the immediate vicinity or in an edge region of the cover plate  10  and air turbulences can be generated. 
     In an example, as indicated in  FIG. 3C , the covering region  11   d  is provided with an abutting portion  40  comprising an abutment surface  42  for abutting the skin in an abutment direction, indicated with arrow  44 , when the door is closed. 
       FIG. 4A  schematically shows a cover plate  10  and a door arrangement  12  according to an embodiment of the invention. If not indicated otherwise, the cover plate  10  and the door arrangement  12  in  FIG. 4A  comprise the same components as the cover plate  10   a  and the door arrangement  12  in  FIG. 1A . 
     The cover plate  10  and the door arrangement  12  in  FIG. 4A  respectively comprise a fastening device  22 ′. The fastening device  22 ′ comprises several hook elements  24  that are arranged in the covering region  11   b  on a side of the cover plate that faces the skin  18 . The fastening device  22 ′ further comprises several hook elements  26  that are arranged on a side of the skin  18  that faces the covering region  11   b . The hook elements  26  may be realized complementary and/or correspondent to the hook elements  24 . 
     All in all, the hook elements  24  are designed for engaging the corresponding hook elements  26  when the door  14  is closed such that the cover plate  10  is fixed on the skin  18  and it is possible to prevent the covering region  11   b  from being lifted off the skin  18 , e.g. due to the relative wind  21 , as well as to prevent the cover plate  10  from fluttering. 
       FIG. 4B  schematically shows a section through the cover plate  10  and the door arrangement  12  in  FIG. 4A  along a central plane A-A, wherein the door  14  illustrated in  FIG. 4B  is closed.  FIG. 4B  clearly shows how the hook elements  24 ,  26  engage into one another when the door  14  is closed such that the covering region  11   b  is fixed on the skin  18 . 
       FIG. 4C  schematically shows details of the cover plate  10  in  FIG. 4B , wherein  FIG. 4C  shows three snapshots during a closing process of the door  14 . In this case, the left snapshot shows the cover plate  10  and the fastening device  22 ′ while the door  14  is open and the right snapshot shows the cover plate  10  while the door  14  is closed. 
     The hook element  24  arranged on the covering region  11   b  of the cover plate  10  protrudes from the cover plate at least in a section  24   a . The hook element  26 , in contrast, has a first region  26   a  that is fastened on the skin  18 , a second region  26   b  that protrudes from the skin  18 , and a third region  26   c  that is realized correspondent to the hook element  24 . All in all, the hook elements  24 ,  26  may be made of a robust and lightweight material, e.g. of aluminium or even of steel, and respectively fastened on the skin  18  and the cover plate  10  by rivets, screws or adhesives. 
     When the door  14  of the door arrangement  12  is closed, the door  14  including the cover plate  10  is initially moved into the door frame  16  in the direction of the skin  10 . This is illustrated in the left snapshot of  FIG. 4C . The cover plate  10  adjoins the skin  18  once the door is completely positioned in the door frame  16 . This is illustrated in the centre snapshot of  FIG. 4C . In order to definitively close and lock the door  14 , the door  14  is lowered in the door frame  16 , wherein this creates the door clearance  20  that is covered with the cover plate  10 . When the door  14  is lowered in the door frame  16 , the hook element  24  engages the hook element  26  such that the covering region  11   b  is pressed against the skin  18  and fixed. This is illustrated in the right snapshot in  FIG. 4C . 
       FIG. 5  shows a section through a door arrangement  12  and a cover plate  10  according to an embodiment of the invention. If not indicated otherwise, the cover plate  10  and the door arrangement  12  in  FIG. 4A  comprise the same components as the cover plate  10   a  and the door arrangement  12  in  FIG. 1A . 
     The door arrangement  12  in  FIG. 5  shows a fastening device  22 ″, wherein the fastening device  22 ″ is a magnetically active or magnetisable film  30  that is arranged in a section of the covering region  11   b  of the cover plate  10  on a side of the cover plate  10  that faces the skin  18 . The fastening device  22 ″ furthermore comprises a magnetic element  28  arranged on the side of the skin  18  that faces away from the cover plate  10 . The magnetically active film  30  is designed for being pulled in the direction of the skin  18  by the magnetic element  28  when the door is closed such that the covering region  11   b  of the cover plate  10  is fixed on the skin. 
     The magnetic element  28  may comprise an electromagnet that may be coupled to a locking mechanism of the door  14  such that the cover plate  10  is automatically fixed on the skin  18  by means of the electromagnet when the door  14  is locked. However, the magnetic element  28  may, for example, also be a permanent magnet. 
     In  FIGS. 6A-6D , an example is shown where the covering region is provided as a morphing structure  46 , which will be explained in the following. The morphing structure  46  is deformable at least in the abutment direction  44 . 
       FIG. 6A  shows an outside view of a door  14 , indicated with a door outline  48  being slightly opened. A door cut-out of the fuselage is indicated with an outline  50 . An arrow  52  indicates a movement of the door when the door is closed. Above the door, the cover plate  10  is provided, which may be riveted to the door, as indicated with an X, see also reference number  54 , indicating rivet positions. 
     As an option, passive guide fittings  56  are provided on the side of the door in the area of the fuselage. 
       FIG. 6B  schematically shows a cross-section through cross-section line A-A in  FIG. 6A . The door  14  is indicated having the cover region  10  above. The cover region  10  is provided as the morphing structure  46 . The fastening device comprises a deformation contact surface  58  that is provided on the covering region on a side of the abutment surface for a pressing abutment of an actuating element  60 , for example referred to as a striker, when the door is closed. The deformation contact surface is arranged on the covering region such that a pressing force, indicated with an arrow  62 , in a direction opposite to the abutment direction leads to a deformation, as indicated with a further arrow  64 , of the covering region such that the abutting portion is deformed in the abutment direction. In  FIG. 6B , a fuselage  66  is further indicated. For example, the striker may contact an intermediate element such as a sealing-like structure  68 . 
     The deformation may also be provided by the sidewards arranged passive guide fittings  56 , and the striker  60  is pressing against the elastic sealing  68  for sealing purposes. However, the striker may also act as an activation element for the deformation, alternatively or in addition to the passive guide fittings  56 . 
       FIG. 6C  shows an outside view of the cover plate being in contact with the skin, provided by contact area of the deformation, which contact area is indicated with patterns  68 . 
     As mentioned above, an option is shown in form of the passive guide fittings  56 , which lead to a compression force  70  that leads to compression areas  72  in the cover plate. For example, for fixation, a slotted hole  74  is provided to allow a transversal replacement or deformation movement of the cover plate. 
     As shown in  FIG. 6D , the morphing leads to a buckling, as indicated with a buckling arrow  76  that results in a contact or pressing force  78  pressing the cover plate against the skin. 
       FIG. 7  indicates a further example, where the fastening device comprises a bimetal arrangement  80  provided in the covering region. The bimetal is configured such that a first degree of deformation is provided in a first temperature range and a second degree of deformation is provided in a second temperature range. The second degree of deformation is larger than the first degree of deformation in the abutment direction. The second temperature range relates to driving condition temperatures of the means of transportations, and the first temperature range relates to temperature conditions above the second temperature range. For example, the first temperature range relates to conditions during loading and embarkment positioning of an aircraft, wherein the second temperature range relates to flying conditions in high altitudes provided for aircraft travel. 
       FIGS. 8A-8C  show a further example of the fastening device comprising an engagement device  82  for activating a movable component  84  provided on the skins edge of the clearance. 
       FIG. 8A  shows a vertical cross-section in a schematic manner, indicating the engagement device attached to the door, and the movable component  84 . The engagement device  82  is provided for causing the movable component to move towards the door, thus covering the clearance. 
       FIG. 8B  indicates a closing movement  86  of the door that results in the engagement device  82  acting on a linkage  88  that is supported and biased by a spring member  90  and that acts on the flap as the movable component  84 . The movable component  84  may be provided with a hinged support  90   a.    
     Due to the door movement, as indicated in  FIG. 8C , the guided hinged flap covers the clearance when the door is closed. 
     In a further example, the fastening device comprises an active engagement device for engaging behind an edge of the skin to pull the cover plate towards the skin such that an abutment force of the abutment surface is increased. 
     For example,  FIGS. 10A-10B  show a mechanically actuated cover plate. 
       FIG. 10A  shows a clamp  92  that is movably attached to the cover plate  10 . An arrow  94  indicates the movability of the clamp  92 . 
       FIG. 10B  shows the clamp  92  in an engaged position thus pulling the cover plate towards the skin, as indicated with arrow  96 . 
       FIG. 11  shows a further cross-section of an example with a latch look mechanism  98 , comprising a lug  99  and a latch  97 , thus resulting in the pressing of the cover plate against the skin of the means of transportation. 
       FIG. 12  shows a further example of a latch lock mechanism  95  comprising a plurality of the lugs  93  and a plurality of latches  91 . When the door is closed, and thus performs a closing movement  89 , the latch and the lugs engage with each other. 
       FIGS. 13A-13D  show a further example of the door cover plate  10  comprising a pneumatic sealing device  87  that has a locking edge  85 . The pneumatic sealing device is deflated in an open state of the door, as indicated in  FIG. 13A , and is inflated when the door is closed such that the locking edge acts as the engagement device, as indicated in  FIG. 13D . 
     In  FIG. 13A , the sealing device  87  comprises an inflatable seal  83 . 
       FIG. 13B  shows the door in a slightly opened state, wherein the door movement is further indicated with movement arrow  81 . 
       FIG. 13C  shows the door in a closed state, but the pneumatic sealing device still being in a deflated state. 
     In  FIG. 13D , the sealing device  87  is inflated, as indicated with the positive difference in pressure +ΔP. Due to the inflation of the sealing device, the locking edge  85  of the sealing device  87  is engaging the edge of the fuselage or the skin. 
       FIG. 14A  shows a further example, where the fastening device comprises a deploying edge  79  of the cover plate  10  that extends when the door is closed to rest against a guide edge of the skin, for example a tapered edge  77 . The deploying edge comprises a respective tapered guiding surface  75 . An activating element  73  is provided, for example a spring  71 . The activating element  73  is provided for deploying the deploying edge, wherein the activating element is activated by the closing movement of the door when the door is closed. 
       FIG. 14A  shows the open position in a cross-sectional overview, and  FIG. 14B  shows a first contact of the deploying edge  79 , also referred to as elevating flap, where a first arrow  69  indicates the first vector of the door closing movement, and a second arrow  67  indicates the further sliding movement of the door when the door is being closed. 
       FIG. 14C  shows the deploying edge  79  in a state when the door is closed. 
       FIG. 14D  shows a further example, where the deploying edge  79  comprises a stepped edge, for example for engaging with the skin of the means of transportation. 
     As a further option, also applicable for the other examples, an actuator  75  is provided as an activating element. 
     According to a further example, shown in  FIG. 9 , as an example with a dual lock fastener attachment, an engagement arrangement is provided for the fastening device. The engagement arrangement is referred to with reference number  73 , and comprises a plurality of clamping pairs  71 , comprising a first and second clamping component  69   a,b  provided on the cover plate and the skin respectively. The first and second clamping components each comprise at least one engaging portion to engage with an engaging portion of the other of the second and the first clamping component. The engaging portions engage behind each other in a direction transverse to the skin&#39;s surface. The engaging portions engage with each other when the door is closed in a closing movement direction in a sliding manner such that the cover plate and the skin are urged against each other in a direction transverse to the closing movement direction. 
     For example, mushroom-like pins may be provided with sidewards engagement portions to engage each other in a sliding movement. 
     As a further example of an engagement arrangement, a dovetail locking system  67  is shown in  FIGS. 15A-15D . 
       FIG. 15A  shows an outside view of the door in an open position. For example, V-shaped fittings  65   a ,  65   b  are attached to the cover plate and to the skin. 
       FIG. 15B  shows the door in a closed position, indicating that the V-shaped fittings are now engaging each other. 
       FIG. 15C  shows a cross-section along the sectional line B-B of  FIG. 15B . As indicated, the door is still slightly open and the dovetails are not in contact yet. 
       FIG. 15D  shows the dovetail locking system in a state when the door is closed and the dovetails are engaging behind each other such that the cover plate is temporarily fixed to the skin. 
       FIG. 16  shows an aircraft  101  with several door openings  12  according to an embodiment of the invention and with several doors  14 , on which a cover plate  10  according to an embodiment of the invention is respectively arranged. 
       FIG. 17  shows a flowchart that illustrates the steps of a method for closing a door  14  on a means of transportation  100  according to an embodiment of the invention. 
     In a first step S 1 , door  14  is moved into the door frame  16  in the direction of the skin  18  of the means of transportation  100 , wherein the door clearance  20  between the skin  18  of the means of transportation  100  and the door  14  is covered with the cover plate  10 . 
     In a second step S 2 , door  14  is locked in the door frame  16  with a transverse motion, wherein the transverse motion may, for example, be a downward motion of the door  14  in the door frame. 
     In a third step S 3 , the cover plate  10  is fixed on the skin  18  by the fastening device  22 ,  22 ′,  22 ″. This may be realized, for example, with hook elements  24 ,  26  on the cover plate  10  and the skin  18 , wherein the hook elements  24 ,  26  are realized in such a way that they engage into one another during the transverse motion and thereby fix the cover plate  10  as described with reference to  FIGS. 4A ,  4 B and  4 C. However, the cover plate  10  may also be fixed by means of a magnetic element  28  on the skin  18  and a magnetically active film on the cover plate  10  as described with reference to  FIG. 5 . 
     Step S 3  may be carried out simultaneously with step S 2 . However, step S 3  may also be carried out after step S 2 . 
     The first step S 1  is also referred to as step a), the second step S 2  as step b), and the third step S 3  as step c). 
     As a supplement, it should be noted that “comprising” does not exclude any other elements or steps, and that “a” or “an” does not exclude a plurality. It should furthermore be noted that features or steps that were described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other above-described exemplary embodiments. Reference symbols in the claims should not be interpreted in a restrictive sense.