Abstract:
A method and apparatus contains and drains leakage from fluid system piping on a mobile platform such as an aircraft. A generally U-shaped channel is formed having outwardly oriented edge flanges and either integral or attached end plates. A pair of drain connections is disposed adjacent to each end plate. A group of fluid lines including at least one flammable fluid line is loaded within the U-shaped channel. A cover plate having outwardly oriented edge flanges aligning with the U-shaped channel edge flanges is positioned over the U-shaped channel. The edge flanges of both the cover plate and the U-shaped channel are joined with a seal such that a fluid-tight assembly results. Fluid leakage from any of the group of enclosed fluid lines discharges through the pair of drain connections. One of the end plates forms a firewall connectable to an engine firewall boundary.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to moving platform fluid systems and more specifically to a method and device to contain and distribute leakage from aircraft mounted fluid systems. 
     BACKGROUND OF THE INVENTION 
     Modern aircraft require a variety of flammable fluids be transported between fluid storage areas and use locations. Typical examples include fluid piping between fuel tanks and engines, between hydraulic storage tanks and hydraulically operated equipment, and between lubricating oil storage areas and mechanical equipment. Fluid transport is typically through systems of piping, tubing or hoses, hereafter referred to in general as fluid lines. 
     Fluid leakage from flammable fluid lines which impinges other piping, wire bundles or structures is undesirable. Flammable fluid leakage adjacent a heat or ignition source is particularly undesirable for the obvious reason of aircraft safety. To contain fluid leakage, aircraft designers apply several methods, including sealing compartments through which fluid lines traverse or applying various designs of fluid line enclosures. 
     One current method to seal compartments involves the complex steps of applying sealing compounds during and after assembly, and installing a network of dedicated drains from each fluid trap (e.g., low point) region to avoid formation of puddles. Multiple low points within the compartment which for functional reasons cannot all be drained are often filled with a leveling compound to permit the drain network to function properly. Each seal and drain network requires confirmation via water test on every unit built. 
     One drawback of this approach is that all other piping, electrical wiring and structure within the compartment is exposed to any fluids that leak. Due to the chance of a leaking fluid line spraying fluid onto wire bundles, extraordinary effort is applied to the design, fabrication, and installation of wire bundles to prevent fluids from running along wires and contacting connectors. Further drawbacks include additional weight, increased labor hours during assembly to apply sealant and leveling compound, and additional time and labor to verify the quality of applied seals. The current methods also place a burden on the aircraft operators to restore the integrity of seals following maintenance actions. Also, when used, leveling compound hides the structure on which it rests, complicating or preventing visual inspection of that structure. 
     To prevent fluid leakage from wetting surrounding items, aircraft designers apply several designs of fluid line shrouds. Common shroud designs apply a tube or metal shroud surrounding the circumference of installed fluid piping and are used to capture and redirect flammable fluid leakage in areas including the space between flammable fluid leakage zones on the propulsion strut(s) and inside the fuselage of commercial aircraft. 
     An exemplary shroud design uses a dedicated sheet metal structure to surround propulsion strut fluid lines transitioning from one leakage zone to another. The sheet metal shroud comprises 2 halves assembled around the installed fluid lines, using clamp blocks and removable fasteners. The shroud halves overlap on assembly and a fillet seal is applied. The ends of the shroud are open to drain leakage into an adjacent leakage zone. Openings are provided in the clamp blocks to permit leaked fluids to flow past. Once leaked fluid exits the shroud assembly, it flows across strut structure to exit via a leakage zone drain system. 
     Another common propulsion strut shroud design advantageously uses a box-beam structure provided for other purposes. This structure is formed as a “U” channel. Fluid line support brackets are attached to the inside floor of the channel. Cover plates are then installed with gaskets and the forward end of the structure is sealed. Any fluid leakage flows aft onto the strut structure before exiting via a leakage zone drain system. 
     A further exemplary application of a common shroud design is applied over fuel line hoses supplying an auxiliary power unit (APU). The APU is frequently located in the aft end of an aircraft fuselage. The APU required fuel is delivered from the aircraft fuel system near the wing to the rear of the fuselage. To contain leakage, the APU fuel feed line is placed within a tubular shroud. The shroud is assembled from tubing and includes a dedicated drain system to purge it of any leaked fluids. The shroud is first installed between fuel supply and APU use points. The APU fuel feed line hose is then inserted within the shroud, and is supported on a shroud inner surface. 
     The disadvantages of common shroud designs are the lack of a firewall structure at a flammable containment end of the shroud, the general lack of dedicated drains to discharge leakage outside the aircraft rather than into another compartment or onto adjacent structure, and the inability to apply the design in a modular concept, wherein the fluid lines are preassembled within the shroud and the entire shroud assembly is installed or removed as a unit. 
     It is therefore desirable to provide a shroud design which overcomes the drawbacks and disadvantages of known shrouds and eliminates the need for compartmental sealing and leveling. 
     SUMMARY OF THE INVENTION 
     According to a preferred embodiment of the present invention, a shroud body internally supports one or more flammable fluid lines and associated support hardware. The combination of the shroud body, fluid lines and support hardware forms a shroud module. The shroud module can be removed/replaced as a unit if a fluid line leaks. The fluid lines are internally supported as an integral unit of fluid lines, allowing for any fluid leakage to traverse the shroud module and discharge through a drain connection disposed at both ends of the module. Shroud body supports are provided on the shroud module. The body supports are designed at a frequency to provide proper support of the shroud module and eliminate shroud body penetrations which create a potential leak path. 
     According to one preferred embodiment of the invention, the shroud module is installed as a unit on the propulsion strut structure of an aircraft. Each shroud module fluid line includes mechanical connections for connection to aircraft systems. All fluid connections within the shroud module are preassembled, and the shroud module is sealed before installation in the aircraft. At one sealed boundary end, the shroud module incorporates a fire-resistant, thick walled plate forming part of a firewall boundary of an aircraft. The firewall plate and its associated transition region are integrally formed. Fire-resistant tubing/piping connections are provided at the exterior, firewall boundary. Aircraft fluid lines are disconnected at these external connections to remove the module. The opposite, i.e., vapor barrier end of the shroud module is preferably provided as a thin-walled plate forming a shroud module fluid tight seal. System fluid lines at the vapor barrier end are provided with mechanical joints or terminate adjacent to the shroud, allowing shroud module removal/replacement. 
     In one preferred embodiment, a shroud module of the present invention comprises two major elements, a lower body and an upper cover. The lower body is formed as a generally U-shaped channel having an outwardly extending peripheral flange. The upper cover of the shroud module also has an outwardly extending peripheral flange, mating with the lower body peripheral flange to form a fluid-tight seal around the periphery of the shroud module. The lower body also includes an integral firewall, drain connections, and discrete attachment elements for installing the assembled shroud module to aircraft structure. The fluid lines and supporting clamp blocks are installed prior to upper cover assembly onto the lower body. The upper cover and lower body are preferably assembled with mechanical fasteners (with application of sealant and/or gasket materials), or by welding the flanged joint. 
     Fluid lines are disposed within the shroud lower body via spaced, elastomeric support blocks which, after installation, provide structural support, restraint, and physical separation between each fluid line. The support blocks are configured to allow any fluid leakage within the shroud module to flow to the drain connections. The support blocks are located at a frequency within the shroud module to provide proper support for the smallest diameter tube or pipe disposed in the module. 
     The shroud module of the present invention is configurable to support different aircraft engine designs requiring different firewall boundaries. The shroud module is preferably formed as a two-piece assembly, but can also be a multi-piece component. In an exemplary application, the shroud module is supported as a unit from aircraft structure such as the propulsion strut. With the exception of the firewall and its associated transition region, the shroud is preferably formed of a thin-wall, lightweight material. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a commercial aircraft having two under-wing supported engines; 
     FIG. 2 is a perspective view of a preferred embodiment of the present invention, showing one of the engines of the aircraft of FIG. 1 having a shroud module of the present invention installed thereon; 
     FIG. 3 is a perspective view of a shroud module of the present invention, having the shroud upper cover installed over the shroud lower body; 
     FIG. 4 is a perspective view of FIG. 3 showing the shroud module having the shroud upper cover removed and the fluid lines of the shroud module shown; 
     FIG. 5 is an elevation view of an auxiliary propulsion unit shrouded hose assembly known in the art; 
     FIG. 6A is a plan view of a common propulsion strut shroud assembly having internally supported fluid lines and open ends for drainage; 
     FIG. 6B is a section view taken along section  6 B— 6 B of the propulsion strut shroud assembly of FIG. 6A further showing the fluid line support elements and through bore supporting fasteners; 
     FIG. 7 is a side elevation view of a first engine configuration using the shroud module of the present invention; 
     FIG. 8 is a side elevation view of a second engine configuration showing the shroud module of the present invention penetrating a firewall relocated from the firewall position shown in FIG. 7; 
     FIG. 9 is a side elevation view of a third engine configuration having the engine body mounts fully supported by the propulsion strut structure and a shroud module of the present invention penetrating the firewall boundary; 
     FIG. 10 is a side elevation view of a fourth engine configuration showing a modified firewall from the firewall of the FIG. 9 arrangement and a shroud module of the present invention; and 
     FIG. 11 is a partial section view taken along section  11 — 11  of FIG. 3, showing the firewall area and its fluid line and drain connectors. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring to FIG. 1, an aircraft  200  having a port engine  202  and a starboard engine  204  is shown. The port engine  202  is supported from a port wing  206  by a port propulsion strut  208 . The starboard engine  204  is similarly supported from a starboard wing  210  by a starboard propulsion strut  212 . 
     Referring to FIG. 2, components of the starboard engine  204  of FIG. 1, and one preferred embodiment for a shroud module of the present invention are shown. Components for the port engine  202  of FIG. 1, or for additional engines (not shown, i.e., of a four engine aircraft or alternate engine arrangements) are similar. The starboard engine  204  comprises an engine body  214  housed within an inlet assembly  216  on a forward face thereof, a two section fan/cowl assembly  218  aft of the inlet assembly  216 , a two section thrust reverser assembly  220  aft of the fan/cowl assembly  218 , and a primary exhaust plug/nozzle  222  aft of the thrust reverser assembly  220 . The engine body  214  is supported from the starboard propulsion strut  212 . The starboard propulsion strut  212  has an aft strut fairing  224  and a trailing edge fairing  226  for improved wing aerodynamics. A plurality of fluid lines  228  runs between the starboard wing  210  (shown in FIG. 1) and the starboard propulsion strut  212 . The fluid lines  228  are partially housed within a shroud module  230  of the present invention as the fluid lines  228  traverse an upper surface  232  of the starboard propulsion strut  212 . 
     Referring to FIG. 3, a shroud module  10  of the present invention is shown. The shroud module  10  comprises a two-piece assembly including a shroud upper cover  12  and a shroud lower body  14 . A straight body length  15  of shroud module  10  is connected to a transition region  16 . The transition region  16  permits fluid lines (shown in FIG. 4) contained within shroud module  10  to change direction or plane of orientation. The transition region  16  includes a transition upper cover  18  which can be formed together with or separate from the shroud upper cover  12  and a transition lower body  20 . The transition lower body  20  further includes a thick-wall plate forming a firewall  22 . The firewall  22  is comprised of fire-resistant metal and is intended to be flanged and fastened or welded to a firewall boundary of an aircraft (not shown). 
     The shroud module  10  of the present invention is shown supported from a wire frame model of a propulsion strut  24  of an aircraft (shown in FIG.  1 ). An exemplary mechanical connector  28  is shown in FIG. 11, typical of the mechanical connectors installed on the firewall  22  to provide fluid line disconnect at the firewall  22 . At an opposite end of the shroud module  10  from the firewall  22  is a vapor barrier  30 , which forms the fluid boundary of the shroud module  10  at this end of the shroud module  10 . 
     Referring now to FIG. 4, the shroud module  10  of FIG. 3 is shown, having the shroud upper cover  12  removed to show the internal arrangement. A plurality of transition fluid lines  26  supporting one or more aircraft systems is connected to the firewall  22  by one of a plurality of fire-resistant fluid lines  186  shown in FIG.  11 . Each of the fire-resistant fluid lines  186  is comprised of a metal material, and connects with the fire-resistant mechanical connectors  28  shown in FIG. 11 on the firewall  22 . A plurality of fluid lines  32  are shown connecting between each of the transition fluid lines  26  and the vapor barrier  30  area of the shroud module  10 . The fluid lines  32  are supported at spaced intervals by a plurality of clamp blocks  34 . As each of the transition fluid lines  26  enters the transition lower body  20 , the transition to the fire-resistant fluid lines  186  is made, and each of the fire-resistant fluid lines  186  is disposed in a cavity  36  formed within the transition lower body  20 . Each of the mechanical connectors  28  is located at the bottom of the cavity  36  and is connected to the firewall  22 . Within the engine fire zone, a plurality of fire-resistant fluid lines  27  are connected to the fire-resistant fluid lines  186  of the shroud module  10  at the firewall  22 , with the mechanical connectors  28 . 
     Referring to both FIGS. 3 and 4, in order to support the shroud upper cover  12  (shown in FIG. 3) to the shroud module  10 , an outwardly extending flange  38  is disposed about the perimeter of the shroud lower body  14 . The flange  38  mates with an upper flange  39  on the shroud upper cover  12 . The joint between the flange  38  and the upper flange  39  is sealed by welding or by the combination of a gasket (not shown) and a plurality of mechanical fasteners (not shown). At the vapor barrier  30  a vapor barrier seal  31  is formed to provide a fluid tight boundary for the shroud module  10 . The vapor barrier seal  31  is preferably comprised of a thin wall metal which is provided with sufficient clearance openings for each of the plurality of fluid lines  32 , and also provides a fluid tight seal on the vapor barrier  30  end of the shroud module  10 . A drain connector  40  is disposed adjacent to the vapor barrier seal  31  to drain any fluid leakage from this end of the shroud module  10 . The drain connector  40  is similar to the firewall drain connector  180  shown in greater detail in FIG. 11, and will therefore not be described in further detail herein. 
     As noted above, the firewall  22  is comprised of a thick-wall, fire-resistant material. It is also desirable to form at least a portion of the transition lower body  20  of a similar fire-resistant material. The fire-resistant fluid lines  186  in the region adjacent to a fire-resistant section  42  of the transition lower body  20  are manufactured from a high temperature, fire-resistant material. To minimize the weight of the shroud module  10 , the size of the fire-resistant section  42 , constructed of fire-resistant material, is preferably kept to a minimum. However, all of the components of the shroud module  10  including the shroud upper cover  12 , the shroud lower body  14 , the transition region  16  and the firewall  22  can be comprised of fire-resistant material. In this exemplary embodiment, all of the materials for the fluid lines  32  are also comprised of a fire-resistant material. The material for the clamp blocks  34  is preferably comprised of an elastomeric material. Therefore, the material for the clamp blocks  34  is selected from a fire-resistant elastomeric material if the shroud module is required to be of entirely fire-resistant materials. 
     Each of the clamp blocks  34  support each of the plurality of fluid lines  32 . The clamp blocks  34  are spaced within the shroud module  10  to support the smallest diameter of the fluid lines  32 . All of the fluid lines  32  and the clamp blocks  34  are modularly loaded in the shroud lower body  14  during off-site assembly. Each of the mechanical connectors  28  at the firewall  22  between the firewall  22  and the fire-resistant fluid lines  186  is mechanically made at this time. The shroud upper cover  12 , including the transition upper cover  18 , is then arranged over the shroud lower body  14 , including the transition lower body  20 , and the junction between the shroud lower body  14  and the shroud upper cover  12  is sealed. The shroud module  10  is then mounted on the propulsion strut  24  of the aircraft. 
     FIGS. 5 and 6 provide exemplary shroud designs commonly used in commercial aircraft. Referring to FIG. 5, an auxiliary propulsion unit (APU) shrouded hose  50  known in the art is shown, The APU shrouded hose  50  is comprised of a flexible fuel hose  52  which is inserted into a tube  54 . The tube  54  is installed in the aircraft, normally in a fuselage area, and is mounted using a plurality of tube clamps  56  which are fastened to the aircraft structure by a plurality of clamp fasteners  58 . The APU shrouded hose  50  is installed in the inner fuselage  60  as shown. The intent of the APU shrouded hose  50  is to contain any fuel leakage from the flexible fuel hose  52  and lead the fuel leakage to a dedicated drain. 
     A fuselage boundary joint  62  normally joins the APU shrouded hose  50  to the aircraft structure. A dedicated drain line  64  is lead away from the APU shrouded hose  50  and is supported by a plurality of drain tube clamps  66 . The dedicated drain line  64  is connected to the APU shrouded hose  50  by a drain fitting  68 . The flexible fuel hose  52  is supported throughout its length by the inner walls of the tube  54 . Static or dynamic loads of the flexible fuel hose  52  are therefore not accommodated by the design of the APU shrouded hose  50 . The APU shrouded hose  50  does not provide for modular installation of the entire unit of the flexible fuel hose  52  and the tube  54 . A firewall is also not provided by the APU shrouded hose  50 . 
     Referring now to both FIGS. 6A and 6B, a propulsion strut shroud assembly  70  known in the art is shown. The propulsion strut shroud assembly  70  is comprised of a two-piece shroud body  72 , a plurality of fluid lines  74 , a plurality of clamp blocks  76  supporting the fluid lines  74 , and a plurality of fasteners  78  which join the halves of the shroud body  72  and also restrain the clamp blocks  76  about each of the fluid lines  74 . The clamp blocks  76  provide fluid passages (not shown) to allow any fluid leakage from any of the fluid lines  74  to pass through the shroud body  72  to either shroud end identified by letters A and B, respectively. The propulsion strut shroud assembly  70  is supported from aircraft structure (not shown) by a support plate  80  and a support plate  82  respectively. 
     The propulsion strut shroud assembly  70  is installed over existing installed fluid lines  74 . Each of the halves of the shroud body  72  are mounted about the installed fluid lines  74  after the clamp blocks  76  are installed on the fluid lines  74 . Each of the fasteners  78  is then installed through preformed apertures (not shown) through the shroud body  72  and fastened to form the shroud body  72 . A seal (not shown) of a sealing material is applied along the joints of the halves of the shroud body  72 . Each of the fluid lines  74  extends through the entirety of the propulsion strut shroud assembly  70 , where connections to continuing system piping are made. Any leakage from any of the fluid lines  74  is captured within the shroud body  72  and transfers to either end A or end B of the shroud body  72 . Any leakage discharges through either of the ends A or B, either onto structure or into drain areas provided within the zones outside of the propulsion strut shroud assembly  70 . 
     No dedicated drain lines are provided for the propulsion strut shroud assembly  70 . If leakage is detected at either end A or end B, the seal between the halves of the shroud body  72  is broken and each fastener  78  is removed such that the shroud body  72  can be removed and the leaking one of the fluid lines  74  is repaired or replaced. The propulsion strut shroud assembly  70  of FIGS. 6A and 6B does not provide for modular installation. The propulsion strut shroud assembly  70  also does not provide for a firewall or thick-wall construction suitable for fire-zone applications. A further disadvantage of the propulsion strut shroud assembly  70  is the plurality of apertures required for each fastener  78  provide potential leakage paths for leaking fluid to exit the propulsion strut shroud assembly  70  at other than end A or end B. 
     Referring now to FIGS. 7-10, preferred embodiments of shroud modules of the present invention which are modified for each of four different engine configurations are shown. FIG. 7 shows a first engine configuration  90 . First engine configuration  90  comprises an engine fan  92 , and an engine body  93 . The engine fan  92  and the engine body  93  are both supported from a propulsion strut  94  by a forward engine mount  96  and an aft engine mount  98 . A firewall boundary  100  is shown. The firewall boundary  100  is comprised of a portion of the propulsion strut  94  and is formed as a boundary between the engine and the aircraft structure. 
     An exemplary shroud module  102  of the present invention is shown. The shroud module  102  is connected at its aft end to the under wing vapor barrier  104  which is adjacent to a wing leading edge  106 . The wing leading edge  106  also forms a flammable fluid leakage control zone  108 . Any leakage from fluid lines within the shroud module  102  drains in the aft direction into the flammable fluid leakage control zone  108 . A firewall  110  is located at the forward end of the shroud module  102 . The firewall  110  forms the containment boundary between the shroud module  102  and the firewall boundary  100 . In one engine design shown by FIG. 7, the first engine configuration  90  comprises an engine having its engine gear box  112  mounted on the engine fan  92 . 
     The arrangements shown in FIGS. 8,  9  and  10  are variations of the engine design and resulting preferred embodiments of the shroud module of FIG.  7 . Therefore, only the differences between FIGS. 8,  9  and  10  and FIG. 6 will be discussed further. 
     Referring now to FIG. 8, a second engine configuration  120  is shown. The second engine configuration  120  comprises an engine fan  122  mounted on an engine body  123 . The engine fan  122  and engine body  123  are both supported from the propulsion strut  124 . The firewall boundary  126  formed for this engine configuration follows the underside of the propulsion strut  124  forward to the aft face of the engine fan  122 . A shroud module  128  is therefore shortened in this engine configuration. The aft end of the shroud module  128  traverses an under-wing vapor barrier  130  and opens into a flammable fluid leakage control zone  132 . 
     Similar to the arrangement of FIG. 7, the flammable fluid leakage control zone  132  is the collection location for any fluid leakage from the individual fluid lines out the after end of the shroud module  128 . The forward end of the shroud module  128  is comprised of the firewall  134 . The firewall  134  penetrates or forms part of the firewall boundary  126  aft of the engine fan  122  as shown. The firewall boundary  126  for the second engine configuration  120  is configured aft of the engine fan  122  because with this engine design, the engine gear box  136  is mounted on the engine body  123  rather than the engine fan  122 . The lubricating oil supplied to the engine gear box  136  is therefore contained aft of the engine fan  122 , thereby reducing the envelope size of the firewall boundary  126 . 
     Referring to FIG. 9, a third engine configuration  140  is shown. The third engine configuration  140  comprises an engine fan  142  mounted on an engine body  143 . A propulsion strut  144  is reduced in length for the third engine configuration  140  because a pair of engine mounts  145  are both connected to the engine body  143  and do not connect to the engine fan  142 . A firewall boundary  146  is therefore formed at the underside of the propulsion strut  144  and continues forward to the aft face of the engine fan  142 . A reduced length shroud module  148  is therefore provided. 
     The aft end of the shroud module  148  penetrates an under-wing vapor barrier  150  and fluid leakage from the fluid lines within the shroud module  148  discharges from the aft end of the shroud module  148  into a flammable fluid leakage control zone  152 . A firewall  154  which is integrally formed with the shroud module  148  is connected at the firewall boundary  146  similar to the previous designs. In addition to having both the engine mounts  145  connected to the engine body  143 , an engine gear box  156  for the engine design of the third engine configuration  140  is also connected to the engine body  143 , therefore permitting the reduced size firewall boundary  146  of this configuration. 
     Referring now to FIG. 10, a fourth engine configuration  160  is shown. The fourth engine configuration  160  differs from the third engine configuration  140  shown in FIG. 9 in that the engine gear box  176  is mounted on an engine fan  162  in the fourth engine configuration  160 . The fourth engine configuration  160  comprises the engine fan  162  supported from an engine body  163 . Both the engine fan  162  and the engine body  163  are supported by a propulsion strut  164 . A firewall boundary  166  is formed for the fourth engine configuration  160  generally following the underside of the propulsion strut  164  to the aft face of the engine fan  162  and then up and over the upper surface of the engine fan  162 . A shroud module  168  of the present invention is shown attached at an aft end to an under-wing vapor barrier  170  wherein a flammable fluid leakage control zone  172  is located. Any fluid line leakage from within the shroud module  168  to its aft end will be collected in the flammable fluid leakage control zone  172 . The forward end of the shroud module  168  includes a firewall  174  which is disposed at a junction between the engine fan  162  and the firewall boundary  166 . The firewall boundary  166  of the fourth engine configuration  160  is disposed above the engine fan  162  because the engine gear box  176  is mounted from the engine fan  162 . 
     Referring back to FIG. 3, the shroud module  10  of the present invention provides a firewall  22  at the end of the shroud module common to the strut to engine interface, the interface herein defined as a firewall boundary. The firewall  22  also acts as a fluid boundary for leakage from any fluid line of the shroud module  10 . The end of the shroud module  10  nearest the strut to wing interface has a fluid leakage boundary, the vapor barrier seal  31 . The vapor barrier seal  31  interfaces with the vapor barrier  30  that forms one boundary of a flammable leakage control zone (e.g., item  108  of FIG.  7 ). Tubing exits the shroud module  10  aft of the vapor barrier  30 , and leakage discharges into the flammable leakage control zone, to permit connecting each fluid line to its respective interface with the wing mounted system. 
     Referring now to FIG. 11, a partial section view of the transition lower body  20  of the shroud module  10  shows the transition lower body  20  connected to the firewall  22  by a plurality of fasteners (not shown) at a typical fastener location C. The firewall  22  is fastenably connected to the propulsion strut structure  178  by a plurality of fasteners (not shown) at a typical fastener location D. A firewall drain connector  180 , one of two ( 2 ) shroud module  10  drain connections, is shown. The firewall drain connector  180  drains any fluid line leakage from the firewall  22  region of the shroud module  10 . A firewall drain plumbing line  182 , shown in phantom, is connected to the firewall drain connector  180  by a mechanical connector  196 . Both the transition lower body  20  and the firewall drain connector  180  are shown sharing a common fastener location C. Presence of fluid at a firewall plumbing discharge point  184  indicates that at least one leaking or damaged fluid line exists within the shroud module  10 . Since the firewall drain plumbing line  182  transitions a fire-zone of the aircraft, the firewall drain plumbing line  182  is comprised of a fire-resistant material. 
     The fire-resistant fluid line  186  is similar in size to each of the plurality of fluid lines  32  (shown in FIG. 4) disposed within the shroud module  10 . In the preferred embodiment shown in FIG. 11, an exemplary transition fluid line  26  connects to the fire-resistant fluid line  186  at the boundary of the area F. The fire-resistant fluid line  186  then transitions to the mechanical connector  28  within the area F via a weld joint  188 . The mechanical connector  28  is fastenably connected to the firewall  22  by a mechanical retention feature. In a preferred embodiment, the mechanical retention feature is a jam nut  190 . Other mechanical retention features known in the art can also be used such a pins, lock-nuts and doubled nuts. The mechanical connector  28  is prevented from rotation due to fluid line assembly motion by an anti-torque retainer  192 . 
     An exemplary fire-resistant fluid line  27  is connected to the mechanical connector  28  by a disconnect fitting  194 . The firewall drain connector  180  is similarly connected to the firewall drain plumbing line  182  by a disconnect fitting  196 . If a leaking fluid line is indicated by fluid discharge at the firewall plumbing discharge point  184 , the disconnect fittings  194  and  196 , respectively, are disconnected to enable removal/replacement of the shroud module  10 . 
     Referring back to FIG. 4, the shroud drain connector  40  is similar to the firewall drain connector  180  (shown in FIG.  11 ), having its own drain connection (not shown) similar to the firewall drain connector  180 , its own shroud plumbing drain line (not shown), similar to the firewall drain plumbing line  182 , and its own disconnect fitting (not shown) similar to the disconnect fitting  196 . The shroud plumbing drain line is preferably provided as a non-fire-resistant material. 
     Penetrations in the shroud module  10  are avoided, and preferably eliminated, since each penetration in a shroud module must be sealed to establish and maintain fluid-tight integrity of the assembled shroud module  10 . The shroud module  10  reduces the risk of flammable fluid contamination of structure, equipment, and wiring. Since any shroud module  10  fluid leakage discharges to an overboard location, and since the use of sealant/leveling compound is reduced or eliminated in the propulsion strut area, visual inspection of the propulsion strut is also improved. 
     The shroud module of the present invention provides several advantages. As a modular design, a pre-assembled configuration of fluid lines are loaded and the shroud module installed as a unit, with a reduction in interfaces and installation time. Any leakage within the shroud module is captured and conveyed overboard via dedicated shroud drain connections. Containing leakage within the shroud module greatly reduces, or eliminates, the need for ensuring that a compartment containing the shroud module is fluid-tight, and eliminates the potential that fluid line leakage can spray adjacent piping, wiring or structure. Dedicated shroud module drains facilitate detection of leaks. In one preferred embodiment, the shroud module provides an integral firewall, permitting the shroud module to be mounted adjacent to a fire-zone. The shroud module of the present invention is also adaptable to any location in a mobile platform requiring fluid line leakage isolation. 
     The description of the invention is merely exemplary in nature and, thus, variation that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other variations will become apparent to the skilled practitioner upon a study of the drawings, specification and the following claims.