Procedure for converting a commercial aircraft and correspondingly converted commercial aircraft

Abstract

Method for converting a commercial aircraft (1) equipped with a passenger cabin (2) for passenger transport to temporary cargo transport, wherein the passenger cabin (2) of the commercial aircraft (1) in its initial state comprises several rows (3, 3') of passenger seats (4) as well as door sills (5') of the passenger doors (5) connected to drainage systems (10) of the commercial aircraft (1) and cabin monuments (6) with toilets and / or galleys, comprising the steps: - Removal of at least the rearmost rows (3) of passenger seats (4) in the direction of flight; - Installation of a splash guard (20') extending over the entire width of the passenger cabin (2) in the area of ​​the foremost furthest row of passenger seats, wherein the splash guard (20') is designed as a splash water barrier (22); - Installation of drainage openings (30) in the floor (9) of the passenger cabin (2), wherein the distance between a newly installed drainage opening (30) and a drainage connection (11) already present for the door sills (5') and / or cabin monuments (6) is less than 50% of the fuselage diameter of the airliner (1); and - Connecting the installed drainage openings (30) to the existing drainage system (10) in such a way that a flow from the drainage opening (30) to the existing drainage system (10) is ensured during the straight flight of the commercial aircraft (1) solely due to gravity.

Description

[0001] The invention relates to a method for converting a commercial aircraft and to a commercial aircraft converted accordingly.

[0002] Commercial aircraft are used for the air transport of passengers and cargo. The vast majority of commercial aircraft currently in operation have a passenger cabin that extends practically the entire length of the aircraft and is equipped with seats (passenger aircraft). Below the passenger cabin is a cargo hold where the luggage of passengers traveling in the passenger cabin, as well as other cargo such as mail, can be transported in specially designed containers or as loose general cargo. The aircraft has several passenger doors and smaller cargo hatches.

[0003] In addition, there are commercial aircraft designed solely for the transport of cargo (cargo planes). These aircraft have no passenger cabin – apart from perhaps a few seats directly behind the cockpit – but rather the entire available fuselage cross-section is designed as a cargo hold. At least one sufficiently large cargo door is provided in the fuselage of the commercial aircraft for loading the cargo hold with designated containers.

[0004] It is known that commercial aircraft equipped for passenger transport can be converted into aircraft solely for cargo transport, a practice particularly common with older aircraft models that may no longer meet increased passenger transport requirements (such as the McDonnell Douglas MD-11). However, this conversion is a complex and costly process. Furthermore, it is generally irreversible, as it often involves significant structural modifications to the aircraft.

[0005] Situations may arise where commercial aircraft designed for passenger transport are needed exclusively for cargo transport for a limited period, making a complete and permanent conversion to a cargo aircraft impractical. In these cases, attempts are made to stow the cargo not only in the cargo hold of passenger aircraft but also in their passenger cabins to increase the aircraft's cargo capacity.

[0006] This often involves removing at least some of the passenger seats from the cabin and moving the cargo, either individually or on pallets, through the passenger doors into the cabin using equipment commonly used in general cargo handling, such as hand pallet trucks. The cargo is then manually secured, for example, with straps and / or nets. Alternatively, specially designed containers for transport in the passenger cabin of an aircraft are described in US document 5,090,639 A.

[0007] When cargo is transported in the passenger cabin, moisture can occur on the cabin floor. For example, liquid may leak from the cargo itself, or rainwater or condensation adhering to the cargo may drip off during transport.

[0008] A passenger cabin in a commercial aircraft is generally not designed to withstand the moisture or liquid quantities that may occur during cargo transport. This applies particularly to the surfaces inside the passenger cabin and various electrical systems.

[0009] Areas in the floor of the passenger cabin may also have openings or similar features through which liquid can pass and subsequently cause corrosion on the aircraft structure behind it.

[0010] Aircraft designed specifically for carrying cargo (cargo planes) or commercial aircraft permanently converted from passenger to cargo planes regularly feature a complex drainage system with an elaborately laid and branched pipe system in order to create drains distributed throughout the cargo hold, through which any liquid that may accumulate can drain away regardless of the aircraft's flight attitude.

[0011] However, a suitable drainage system is very expensive and requires time-consuming implementation, which is why it is generally not an option for a passenger aircraft that is only used temporarily as a cargo plane.

[0012] Document US 6 302 358 B1 describes a system for converting an aircraft from cargo to passenger operation and vice versa. This includes, among other things, the installation of a cabin partition and a drainage system.

[0013] Document DE 10 2004 035 854 A1 concerns a leak-free replaceable adapter for routing a liquid line through the floor of an aircraft.

[0014] Document US 5 303 739 A is directed at a water supply for an aircraft in which the wastewater can be drained using gravity.

[0015] Document DE 10 2011 001 267 B4 describes a drainage system for removing condensation that occurs inside an aircraft fuselage behind insulation on an aircraft outer skin and is conveyed into a collecting pipe by means of hydrophilic pipes.

[0016] The object of the present invention is to create a conversion of a commercial aircraft designed for passenger transport for temporary cargo transport, in which the disadvantages known from the prior art no longer occur or only occur to a reduced extent.

[0017] This problem is solved by a method for retrofitting according to the main claim, and by a commercial aircraft retrofitted according to the method according to the dependent claim. Advantageous further developments are the subject of the dependent claims.

[0018] Accordingly, the invention relates to a method for converting a commercial aircraft equipped with a passenger cabin for passenger transport to temporary cargo transport, wherein the passenger cabin of the commercial aircraft in its initial state comprises several rows of passenger seats as well as door sills of the passenger doors connected to a drainage system of the commercial aircraft and cabin monuments with toilets and / or galleys, comprising the steps: - Removal of at least the rear rows of passenger seats in the direction of flight; - Installation of a splash guard extending across the entire width of the passenger cabin in the area of ​​the foremost row of passenger seats, wherein the splash guard is designed as a splash water barrier; - Installation of drainage openings in the floor of the passenger cabin, wherein the distance between a newly installed drainage opening and a drainage connection already present for the door sills and / or cabin monuments is less than 50% of the fuselage diameter of the commercial aircraft; and - Connecting the installed drainage openings to the existing drainage system in such a way that a flow from the drainage opening to the existing drainage system is ensured during the straight flight of the commercial aircraft solely due to gravity.

[0019] Furthermore, the invention relates to a commercial aircraft which has been retrofitted according to the inventive method.

[0020] The invention recognizes that by utilizing or extending the drainage systems already installed in passenger aircraft for specific purposes, located in the area of ​​the passenger doors and at least some cabin structures, and simultaneously providing splash protection, sufficient drainage is regularly achieved in a passenger cabin converted for cargo transport. Any liquid that may accumulate on the floor of the passenger cabin can then drain away directly through a drainage opening in a variety of flight attitudes typically encountered during a flight. In more unusual flight attitudes, however, it is intentionally accepted—unlike with known drainage systems for cargo aircraft—that any liquid present on the floor of the passenger cabin may not be able to drain away directly through a drainage opening. To prevent the liquid from entering undesirable areas, suitable splash protection is provided.This also takes into account the finding that the total amount of liquid expected to be on the ground at any given time is sufficiently small that a negative influence on the flight characteristics of the commercial aircraft due to weight shift can be practically ruled out.

[0021] A "splash guard" is a wall or raised platform that seals against the floor and can prevent a splash of liquid up to its height. In many cases, a splash guard spanning the entire width of the passenger cabin is sufficient to prevent liquid from flowing from the cargo area towards the cockpit. If all passenger seats are removed from the cabin, this splash guard should be positioned at the front of the cabin – specifically, in the area of ​​the frontmost removed row of seats. If some rows of seats remain in the front of the cabin, the splash guard should be positioned behind the last remaining row.

[0022] "Cabin monuments" as defined in the invention are prefabricated assemblies specifically adapted to the available installation space in the aircraft cabin. Essential components of cabin monuments can include galley assemblies and sanitary assemblies such as toilet assemblies. In particular, galley and sanitary monuments typically feature a drainage connection to allow for the removal of splashed water or spilled liquids.

[0023] Due to the fuselage cross-section and the arrangement of the passenger doors, rain regularly hits the door sill when the passenger door is open. To prevent this rainwater from entering the cabin, the passenger door sills are therefore equipped with drainage openings that also lead into a drainage system.

[0024] While several cabin monuments and / or door sills can certainly be connected to a common drainage system, the drainage systems in commercial aircraft designed for passenger transport are generally limited to specific fuselage sections, namely the areas of the passenger doors, where cabin monuments with drainage connections are often also located. A common drainage system extending over the entire passenger cabin is not provided for in passenger aircraft.

[0025] The drainage openings to be provided according to the invention are to be located exclusively in the vicinity of existing drainage systems, namely at a distance of less than the fuselage diameter from the nearest drainage connection for a cabin monument or a door sill. This limits the length of the pipe to be laid for connection from the drainage opening to the drainage system, thus ensuring a low pipe weight. Furthermore, the pipe can then be laid at a consistent angle to the cabin floor such that, under a variety of flight attitudes, fluid flows from the drainage opening into the existing drainage system due to gravity.

[0026] Against this background, the distance between a newly installed drainage opening and an existing drainage connection for the door sills and / or cabin monuments is less than 50% of the aircraft's fuselage diameter. This can further enhance the described technical effects.

[0027] In some types of commercial aircraft, stairways leading to, for example, toilets located on a lower deck, are provided in the passenger cabin. To prevent liquids originating from cargo from entering the lower deck via these stairways, they can be completely sealed with a plate or similar device. Alternatively, it is preferable for them to be protected by a splash guard. A similar principle applies to the area of ​​the passenger cabin behind the rearmost drain opening (in the direction of flight). By protecting this area with a splash guard, the ingress of liquids into this area, which would otherwise have to flow back through a drain to drain away, can be prevented from the outset.

[0028] The at least one splash guard can be a profile, preferably an edge profile, that can be attached to the floor of the passenger cabin. The profile can be provided with a rubber coating or other sealing material on the side intended to rest on the floor in order to prevent liquid from penetrating underneath the profile. In its installed state, the profile preferably has a height of at least 70 mm above the floor, and more preferably a height of at least 50 mm above the floor. These minimum heights have proven sufficient for the liquid accumulation typical of cargo transport scenarios in a commercial aircraft retrofitted according to the invention.

[0029] At least the splash guard in the area of ​​the furthest front row of passenger seats is designed as a splash guard, preferably a textile splash guard. If a splash guard is designed as a splash guard, it extends not only to a certain height above the floor of the passenger cabin, but also covers the entire free cross-section of the passenger cabin along its length. A suitable splash guard can not only contain any liquid that may be present on the floor of the passenger cabin, but also capture all liquid splashes. The splash guard can, in particular, be a textile splash guard that is attached to the floor and walls of the passenger cabin and covers the free cross-section with a liquid-impermeable fabric.As an alternative to a liquid-impermeable textile, a liquid-impermeable film can also be used.

[0030] If, during the conversion of a commercial aircraft originally designed for passenger transport, a cabin monument connected to a drainage system is also removed, it is preferable to convert the drainage connection provided for the removed cabin monument into a drainage opening for the discharge of liquid from the floor. For example, it must be ensured that the opening of the drainage connection is at or below floor level.

[0031] To prevent liquid from penetrating the structure of the aircraft below the floor, it is preferred that the passenger cabin floor be lined with a waterproof membrane. To prevent cargo workers from slipping on the potentially damp membrane, the membrane is preferably provided with a non-slip coating on its upper surface.

[0032] For an explanation of the commercial aircraft according to the invention, reference is made to the preceding statements.

[0033] To revert a retrofitted commercial aircraft to its original configuration, in principle only at least one splash guard needs to be removed before the passenger seats can be reinstalled. The existing drainage openings and their connection to a drainage system can remain in the aircraft, with suitable covers provided if required.

[0034] The invention will now be described by way of example with reference to advantageous embodiments and the accompanying drawings. These show: Fig. 1: a commercial aircraft equipped with a passenger cabin for passenger transport before a conversion according to the invention; Fig. 2: the commercial aircraft converted according to the inventive method made of Fig. 1; Fig. 3-6: various arrangement and connection variants of drainage openings provided according to the invention; and Fig. 7, Fig. 8: Various design variants of the splash guard to be installed according to the invention.

[0035] In Fig. Figure 1 schematically shows the layout of a passenger cabin 2 of a commercial aircraft designed for transporting passengers. Rows 3 of passenger seats 4 in various booking classes are arranged throughout the passenger cabin 2.

[0036] In the area of ​​the passenger doors 5, which, unlike purely emergency exit doors, are generally designed for boarding and alighting, various cabin monuments 6 are arranged, some of which – namely those with toilets and some of the cabin monuments forming a galley – are connected to a drainage system 10 (see Fig. 3, Fig. 4 to Fig. 5) are connected. Also the door sills 5' of the passenger doors 5 designed to collect rain (see Fig. 5 and Fig. 6) are connected to a drainage system 10.

[0037] Since the cabin monuments 6 of the passenger cabin 2 to be connected to a drainage system 10 are located exclusively in the area of ​​the passenger doors 5, the airliner 1 only has a drainage system 10 in the areas 7 of the passenger doors 5.

[0038] Passenger cabin 2 also includes a staircase 8 leading to toilets located below passenger cabin 2.

[0039] For the conversion of the commercial aircraft 1 according to Fig. 1. According to the inventive method, the passenger seats 4 of all rows 3, with the exception of the first row 3', are first removed. Virtually all cabin monuments 6 in the area of ​​the passenger cabin 2 behind the first row 3' of passenger seats 4 are also removed, regardless of whether they are connected to a drainage system 10 or not. The exception to this are the cabin monuments 6 located laterally next to the stairwell 8. While the cabin monuments 6 are primarily removed to create a cargo space that is as unobstructed as possible, into which cargo can be brought through passenger doors 5 and then freely moved within it, the latter is generally not possible in the area of ​​the stairwell 8 due to its floor opening and the surrounding railing. Consequently, the cabin monuments 6 can remain in this area.

[0040] The same applies to the cabin monuments 6 in the rear of the airliner 1. Due to the narrowing of the cross-sectional area of ​​the airliner 1, the rear area is not very suitable for cargo transport.

[0041] Immediately behind the first row 3' of passenger seats 4 remaining in passenger cabin 2, around the stairway 8 and in the rear area of ​​passenger cabin 2, from which no more cargo is to be transported, a splash guard 20, 20' is provided in each case, with which any liquid that may be on the floor 9 of passenger cabin 1 is prevented from penetrating into undesirable areas - namely the front area of ​​passenger cabin 2 towards the cockpit, as well as into the lower deck and the rear area of ​​the airliner 1.

[0042] The splash guard 20 in the rear area of ​​the cabin 20 is designed as an edge profile 21 attached to the floor 9 of the passenger cabin 2, as shown in Fig. Figure 7 schematically depicts a section 1' of the fuselage of the airliner 1. The edge profile 21 is sealed against the floor 9, preventing any liquid from passing between the floor 9 and the edge profile 21. Furthermore, it extends across the entire width of the passenger cabin 2, thus preventing any liquid from passing through from the sides.

[0043] The splash guard 20 around the stairwell 8 is designed similarly. However, the edge profile does not extend across the entire width of the passenger cabin 1, but is arranged to completely surround the stairwell 8 (see figure). Fig. 2).

[0044] The splash guard 20' behind the remaining first row 3 at passenger seats 4 is designed as a textile splash guard 22. The splash guard 22 consists of a waterproof textile, which is attached to the floor 9 and the inner wall of the passenger cabin 2 in such a way that it covers the entire cross-section of the passenger cabin 2. The splash guard 22 is sealed, particularly at the floor 9 and the inner wall, at least near the floor, so that no liquid can bypass the splash guard 22. A waterproof zipper 23 is provided in the splash guard 22, forming a textile door 24. When the zipper 23 is open, the splash guard 22 can be accessed.

[0045] Within the section of passenger cabin 2 from which the passenger seats 4 have been removed, drainage openings 30 are provided in the floor 9 of passenger cabin 2 in or near the areas 7 where a drainage system 10 is generally provided. The distance between such a newly provided drainage opening 30 and the nearest existing drainage connection for a cabin monument 6 or a door sill 5' is always less than 50% of the fuselage diameter. The drainage openings 30 are then connected to the nearest drainage system 10 in such a way that, at least during straight-ahead flight of the aircraft 1, liquid flows from the drainage opening 30 to the drainage system 10 solely by gravity.

[0046] The entire passenger cabin 2 is lined with waterproof foil with a non-slip surface in the areas designated for cargo.

[0047] In Fig. 3, Fig. 4, Fig. 5 to Fig. Figure 6 shows various configurations of drainage openings 30 and their connection to existing drainage systems 10. The figures each show a schematic section through the fuselage of the airliner 1, e.g., according to... Fig. 2.

[0048] An existing drainage system 10 comprises drainage ports 11 for connecting cabin monuments 6 or door sills 5', and a drainage valve 12 through which accumulated fluid can be drained. The drainage ports 11 and the drainage valve 12 are connected to each other via lines 13 such that, in most flight attitudes of the aircraft, fluid flows from the drainage ports 11 to the connected drainage valve 12 solely by gravity.

[0049] In the embodiment according to Fig. In section 3, a cabin monument 6, originally connected to the drainage system 10 via a drainage connection 11, has been removed (and is therefore only shown with dashed lines). The now-vacant drainage connection 11 has been converted into a drainage opening 30', which is directly connected to the drainage valve 12 via the existing line 13.

[0050] In addition, three further drainage openings 30, distributed across the width of the passenger cabin 2, are incorporated into its floor 9. These drainage openings 30 are connected to the drainage system 10 and its line 13 via additional lines 31 in such a way that, at least during straight-ahead flight, any liquid entering through the drainage openings 30 reaches the drainage system 10 and, via its lines 13, the drainage valve 12, purely by gravity.

[0051] In the exemplary embodiment according to Fig. 4. Two cabin monuments 6, originally connected to the drainage system 10 on either side of the passenger cabin 1, have been removed. The respective freed drainage connections 11 have been converted into drainage openings 30'. Furthermore, two additional drainage openings 30 have been installed, each connected to the drainage system 10 or its line 13 by additional lines 31. Here, too, the lines 13 are laid in such a way that, at least during straight-ahead flight, any liquid entering the drainage system 10 or, via its lines 13, reaching the drainage valve 12, purely by gravity.

[0052] Fig. Figure 5 shows an embodiment in the area of ​​passenger doors 5 with door sills 5' connected to the drainage system 10 via drainage connections 11. In addition, a cabin module 6 is connected via another drainage connection 11, which remains in the passenger cabin 2 even after the conversion according to the invention has been carried out.

[0053] Here too, additional drainage openings 30 are introduced into the floor 9 of passenger cabin 2 and - as with the Fig. 3 and Fig. 4 already explained - connected to the drainage system already present in this hull section by additional lines 31.

[0054] In the embodiment according to Fig. Originally, only the door sills 5' of the passenger doors 5 are connected to a drainage system 10. Additional drainage openings 30 are connected to this drainage system 10 via pipes 31.

Claims

[1] Method for converting a commercial aircraft (1) equipped with a passenger cabin (2) for passenger transport to temporary cargo transport, wherein the passenger cabin (2) of the commercial aircraft (1) in its initial state comprises several rows (3, 3') of passenger seats (4) as well as door sills (5') of the passenger doors (5) connected to drainage systems (10) of the commercial aircraft (1) and cabin monuments (6) with toilets and / or galleys, comprising the steps: - Removal of at least the rearmost rows (3) of passenger seats (4) in the direction of flight; - Installation of a splash guard (20') extending over the entire width of the passenger cabin (2) in the area of ​​the foremost furthest row of passenger seats, wherein the splash guard (20') is designed as a splash water barrier (22); - Installation of drainage openings (30) in the floor (9) of the passenger cabin (2), wherein the distance between a newly installed drainage opening (30) and a drainage connection (11) already present for the door sills (5') and / or cabin monuments (6) is less than 50% of the fuselage diameter of the airliner (1); and - Connecting the installed drainage openings (30) to the existing drainage system (10) in such a way that a flow from the drainage opening (30) to the existing drainage system (10) is ensured during the straight flight of the commercial aircraft (1) solely due to gravity. [2] Method according to claim 1, characterized by , that stairways (8) and / or the area of ​​the passenger cabin (2) behind the rearmost drainage opening (30) in the direction of flight are protected by a splash guard (20) from the ingress of liquid located on the floor (9) of the passenger cabin (2). [3] Method according to any one of the preceding claims, characterized by , that at least one splash guard (20) is an edge profile (21) that can be attached to the floor of the passenger cabin. [4] Method according to any one of the preceding claims, characterized by , that the surge protection (20') is designed as a textile splash water protection wall (22). [5] Method according to any one of the preceding claims, characterized by , that at least one cabin monument (6) is removed and the drainage connection (11) provided for the removed cabin monument (6) is converted into a drainage opening (30'). [6] Method according to any one of the preceding claims, characterized by , that the floor (9) of the passenger cabin (2) is lined with a waterproof film, preferably with a non-slip surface. [7] commercial aircraft (1), characterized by that it has been converted according to a method according to one of the preceding claims.

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