Patent Description:
The present disclosure generally relates to the field of aircraft lighting and, more particularly, to aircraft lighting incorporated by a tail cone of the aircraft.

Almost all aircraft are equipped with exterior lights. In particular, large passenger airplanes are provided with a wide variety of exterior lights. The exterior lights are provided for various different purposes, such as for allowing the passengers and/or air crew to view the outside, for passive visibility, for signaling purposes, and the like. Examples of such exterior lights include navigation lights, also referred to as position lights, anti-collision lights, landing lights, taxi lights, runway turn-off lights, and the like.

Light emitting diodes or LEDs are a potential kind of light source for exterior aircraft lights. They are commonly mounted on a mounting board that is adapted for the arrangement and connection of electronic components. Such a mounting board may be a printed circuit board (PCB). There are a number of issues around the use of such printed circuit boards. For example, electric connectors of the PCB and, potentially, other electronic components may be subject to undesired electrostatic discharge. As another example, excessive heat may be built up at the printed circuit board during operation. The foregoing issues are particularly severe in exterior aircraft lights, as they are required to operate in hazardous conditions. Depending on their location on the aircraft, they may have to withstand large aerodynamic forces, strong vibrations, large temperature variations and/or hazardous gases, such as exhaust fumes. <CIT> describes a solid state tail light for an aircraft, comprising a mounting bracket which preferably abuts and attaches to the aircraft with a gasket interposed therebetween. The gasket, in addition to aiding in the securement of the light to the aircraft, also preferably provides thermal insulation and EMI suppression. <CIT> describes an aircraft light.

A first aspect provides an aircraft tail cone assembly that includes a tail cone and a lighting unit that is mounted on the tail cone, as defined in independent claim <NUM>.

A number of feature refinements and additional features are applicable to the first aspect. These feature refinements and additional features may be used individually or in any combination. The following discussion is applicable to the first aspect, up to the start of a discussion of a second aspect. The lighting unit may be installed on any appropriate surface of the tail cone (e.g., an end section or end surface of the tail cone, including any discharge housing incorporated by the tail cone), including in proximity to an exhaust outlet of the tail cone. An auxiliary power unit may be disposed within the tail cone and its exhaust may be directed through at least one exhaust outlet of the tail cone (e.g., a discharge housing at a distal end of the tail cone, where this discharge housing includes at least one exhaust outlet).

The thermal insulator may be of any appropriate configuration, including being formed in a number of different sections. The thermal conductivity of the thermal insulator may be at least about <NUM>% less than a thermal conductivity of the mounting flange in various embodiments. The thermal conductivity of the thermal insulator may be at least about <NUM>% less than a thermal conductivity of the mounting flange in various embodiments. At least about <NUM>% of a surface area of the proximal end of the lighting unit (e.g., a mounting end of the lighting unit) may be defined by the thermal insulator in various embodiments, while at least about <NUM>% of a surface area of the proximal end of the lighting unit may be defined by the thermal insulator in various embodiments. The proximal end of the lighting unit may be an at least substantially flat surface.

The mounting flange may be part of the lighting unit housing, the lighting unit housing may be of an integral or one-piece construction, or both. The mounting flange may include a base and at least one support that extends from this base in a direction of the portion of the tail cone to which the lighting unit is mounted. The thermal insulator may also extend from the base in a direction of the portion of the tail cone to which lighting unit is mounted. The thermal insulator may occupy a space between at least one pair of supports for the mounting flange, and thereby may occupy a space between each adjacent pair of supports for the mounting flange.

A printed circuit board (or circuit board assembly) may be disposed within the lighting unit (e.g., within an interior of the lighting unit; the printed circuit board may be enclosed within the lighting unit). The light source(s) may be at least operatively interconnected with this printed circuit board, including where the light source(s) is disposed on/mounted to the printed circuit board. The printed circuit board may be disposed on the above-noted base of the mounting flange. The printed circuit board and the thermal insulator may be disposed on opposite sides of the above-noted base of the mounting flange.

The lighting unit housing can include the mounting flange having at least one open space or pocket that projects in a direction of a structure when the lighting unit is in an installed configuration (e.g., when the lighting unit is mounted on/to such a structure, such as an aircraft tail cone), as well as at least one support that extends from the base in the direction of the tail cone. An output from the light source(s) is directed through the cover. The cover and mounting flange may define at least in part opposite ends of the lighting unit. The thermal insulator is disposed within one or more of the noted open spaces of the mounting flange.

Said thermal conductivity of said thermal insulator can be at least about <NUM> percent less than said thermal conductivity of said mounting flange.

Said mounting flange and said thermal insulator can be formed from different materials.

Said mounting flange can comprise at least one of a metal or a metal alloy.

Said lighting unit housing can comprise said mounting flange.

At least <NUM>% of a surface area of said proximal end of said lighting unit can comprise said thermal insulator.

Said proximal end can be an at least substantially flat surface.

Said thermal insulator can extend from said base in a direction of said tail cone, and wherein said thermal insulator occupies a space between at least one pair of supports of said at least one support.

Said at least one support can comprise at least one pair of annular supports, with a first annular support of said at least one pair of annular supports being spaced inwardly from a second annular support of said at least one pair of annular supports, and with said thermal insulator being disposed between said first annular support and said second annular support of said at least one pair of annular supports.

Said first annular support and said second annular support can each have a closed perimeter of any appropriate shape.

Said lighting unit can further comprise a printed circuit board disposed within said lighting unit, wherein said at least one light source is at least operatively interconnected with said printed circuit board, and wherein said thermal insulator and said printed circuit board are disposed on opposite sides of said base.

Said printed circuit board can be disposed on said base.

Said base and each said support can be formed from a common material.

Said mounting flange and said lighting unit housing can be formed from said common material.

Said common material can be at least one of a metal and a metal alloy.

Said mounting flange comprises at least one open space that projects in a direction of said tail cone, and wherein said thermal insulator is disposed within each open space of said at least one open space of said mounting flange.

Said lighting unit can further comprise a printed circuit board disposed within said lighting unit, wherein said at least one light source is at least operatively interconnected with said printed circuit board, and wherein said thermal insulator is disposed between said printed circuit board and said tail cone.

Said mounting flange can comprise a base, wherein said printed circuit board is disposed on a first surface of said base that projects toward an interior of said lighting unit housing, and wherein said thermal insulator extends from a second surface of said base that is opposite said first surface.

Said at least one light source can comprise an LED.

The aircraft tail cone assembly can comprise an auxiliary power unit disposed within said tail cone, wherein an exhaust from said auxiliary power unit is directed through at least one exhaust outlet of said tail cone, and wherein said lighting unit is in proximity to said at least one exhaust outlet.

The aircraft tail cone assembly can comprise a cover for said lighting unit housing, wherein an output from said at least one light source is directed through said cover, and wherein said cover and said mounting flange are disposed on opposite ends of said exterior aircraft lighting unit.

An understanding of the present disclosure may be further facilitated by referring to the following detailed description and claims in connection with the following drawings. Any reference to "in accordance with various embodiments" in this Brief Description of the Drawings also applies to the corresponding discussion in the Detailed Description.

With reference to <FIG>, there is illustrated a representative aircraft <NUM> that may incorporate a lighting unit in accordance with <FIG> that will be discussed in more detail below. The aircraft <NUM> includes a fuselage <NUM> and wings <NUM>. Each wing <NUM> has a corresponding leading edge 115a (e.g., a "leading" structure/surface of the corresponding wing <NUM> during movement of the aircraft <NUM> through the air). The fuselage <NUM> includes a cockpit <NUM> and a tail cone <NUM>, which can be substantially integral to the fuselage <NUM>. The aircraft <NUM> also includes engines <NUM> which can be affixed to the wings <NUM> and/or to the fuselage <NUM>, and that may be controlled in any appropriate manner (e.g., by one or more control systems, for example one or more engine control systems). As used herein, the term "engine" is to be understood as including the engines themselves and nacelles <NUM> which contain the engines. Each nacelle <NUM> includes a leading edge 150a (e.g., a "leading" structure/surface of the nacelle <NUM> during movement of the aircraft <NUM> through the air). Although shown in <FIG> generally as a turbofan aircraft in which the engines <NUM> are gas turbine engines, it should be noted that the aircraft <NUM> can be any suitable type of aircraft having any suitable number of engines of any suitable type.

<FIG> illustrates a tail portion <NUM> of an aircraft <NUM> having an external tail light <NUM> (e.g., at least one of a strobe light and a position light). The tail light <NUM> includes a cover or lens <NUM> and is located in close vicinity to the exhaust gas outlet <NUM> of an auxiliary power unit or APU <NUM> that ejects a fast and hot exhaust gas jet stream <NUM> through the exhaust gas outlet <NUM> in an ejecting direction <NUM>.

<FIG> illustrates a portion of a representative aircraft <NUM>, namely a tail cone <NUM>. A distal end of the tail cone <NUM> includes a discharge housing <NUM>. This discharge housing includes an end section <NUM>. This end section <NUM> includes an exhaust port, aperture, or outlet <NUM> through which an exhaust from an APU (within the tail cone <NUM>) may be directed. An external lighting unit <NUM> (e.g., a tail light) is mounted to the end section <NUM> of the discharge housing <NUM> in proximity to the exhaust port <NUM>. The lighting unit <NUM> includes a lighting unit housing <NUM> and a cover or lens <NUM>. One or more light sources (not shown) are disposed within the interior of the lighting unit <NUM> and emit light through the cover <NUM>.

<FIG> illustrates a representative APU <NUM> (also referred to as an "auxiliary power system") that could be utilized by the aircraft <NUM> of <FIG>, the aircraft <NUM> of <FIG>, the aircraft <NUM> of <FIG>, or any other appropriate aircraft. The APU <NUM> includes a gas turbine engine for use on an aircraft to supply electric and pneumatic power to the aircraft systems as an auxiliary or secondary source of power. Any other suitable engine may be employed. As shown in <FIG>, APU <NUM> includes an inlet <NUM> through which ambient air is drawn, a flow splitter <NUM> for splitting the inlet air into an engine stream air 203A and a load stream air 203B, a high pressure compressor (HPC) <NUM> for pressurizing the engine stream air 203A, a combustor <NUM> in which the compressed engine stream air 203A is mixed with fuel and ignited for generating an annular combustion stream <NUM> of hot combustion gases, and a turbine section <NUM> having turbines, for example, a two-stage turbine as shown in <FIG> or other multi-stage turbine, for extracting energy from the combustion gases which then exhaust to engine exhaust <NUM>. The HPC <NUM>, combustor <NUM> and turbine section <NUM> form part of the gas turbine engine portion of the APU <NUM>. The gas turbine engine defines a gas path through which gases flow, such as engine stream air 203A and combustion stream <NUM>, to drive the engine. A power shaft <NUM> is connected to one or more turbines of turbine section <NUM> and HPC <NUM>. Power shaft <NUM> is driven by the one or more turbines of turbine section <NUM>.

APU <NUM> further includes a load compressor (LDC) <NUM> for pressurizing the load stream air 203B to generate load compressor air <NUM> for use by an environment control system (ECS) <NUM> of an aircraft in which APU <NUM> is installed. ECS <NUM> may provide air supply, thermal control, and cabin pressurization in the aircraft. In various embodiments, LDC <NUM> may be linked mechanically to HPC <NUM> and turbine section <NUM> of the gas turbine engine by way of power shaft <NUM>, and thus LDC <NUM> may be drivingly coupled to the gas turbine engine. APU <NUM> may also include a bypass excess air pathway or conduit establishing fluid communication between LDC <NUM> and the engine exhaust for directing at least some of excess load compressor air <NUM> to, in an example, an exhaust pathway to engine exhaust <NUM>. Alternatively, the excess load compressor air <NUM> may be directed to another location upstream of one or more turbines of turbine section <NUM> in order to permit energy from the excess load compressor air <NUM> to be converted into useful work by the gas turbine engine of APU <NUM>.

APU <NUM> may also be adapted to supply electric power to aircraft systems by way of a generator <NUM>. Generator <NUM> may by an oil-cooled generator and include a gearbox for transferring power from power shaft <NUM> of APU <NUM> to electric power. In an example, generator <NUM> may operate at an least substantially constant speed.

In use, inlet <NUM> draws air into APU <NUM>, and flow splitter <NUM> splits the inlet air into engine stream air 203A and load stream air 203B. Engine stream air 203A is directed to HPC <NUM>. HPC <NUM> pressurizes the air by rotating. In combustor <NUM>, the compressed engine stream air 203A is mixed with fuel and ignited, generating combustion stream <NUM> of hot combustion gases. Propulsion of combustion stream <NUM> through turbine section <NUM> rotates the turbines of turbine section <NUM>, thus extracting energy from the combustion gases, and rotating power shaft <NUM> that is drivingly coupled to one or more turbines in turbine section <NUM>. Combustion stream <NUM> then exits APU <NUM> as engine exhaust <NUM>. Load stream air 203B is directed to LDC <NUM>. In various embodiments in which LDC <NUM> is linked mechanically to HPC <NUM> and turbine section <NUM>, for example, by way of power shaft <NUM>, rotation of power shaft <NUM> drives the rotation of LDC <NUM>. The rotation of LDC <NUM> compresses air within LDC <NUM>, generating compressed load compressor air <NUM>. The compressed load compressor air <NUM> may then be directed to ECS <NUM> of the aircraft. As such, APU <NUM> is adapted to supply load compressor air <NUM> for pneumatic power to ECS <NUM>.

Load compressor air <NUM> generated by LDC <NUM> may be regulated by inlet guide vanes and bleed valves (not shown). However, since the rotation of LDC <NUM> may be mechanically linked to HPC <NUM>, as HPC <NUM> rotates, so does LDC <NUM>. In various embodiments, LDC <NUM> and HPC <NUM> rotate at the same speed. In some embodiments, LDC <NUM> and HPC <NUM> rotate at different speeds.

Thus, in various embodiments in which LDC <NUM> is mechanically linked to HPC <NUM>, any time HPC <NUM> rotates LDC <NUM> will generate load compressor air <NUM>. As shown in <FIG>, if more load compressor air <NUM> is generated by LDC <NUM> than is required by ECS <NUM>, unused excess load compressor air <NUM> may be released by a bleed valve (not shown) and directed along an exhaust pathway to be injected into engine exhaust <NUM>. Rotation of power shaft <NUM> may also transfer power to the gearbox of generator <NUM> for electric power. The sizing of APU <NUM> may be determined by the requirements at the highest commanded generator <NUM> power and/or ECS <NUM> pneumatic power, leaving APU <NUM> running below its maximum power at other points of the operating envelope.

An exterior aircraft lighting unit is illustrated in <FIG>, is identified by reference numeral <NUM>, may be used in place of the external tail light <NUM> in <FIG> or the external lighting unit <NUM> of <FIG>, or may be installed on any appropriate aircraft and including where such an aircraft incorporates a tail cone with an APU and where the lighting unit <NUM> may be installed at any appropriate location on the tail cone and including in proximity to APU exhaust from the tail cone. In any case, the lighting unit <NUM> includes a lighting unit housing <NUM>. Components of the light unit housing <NUM> include an annular sidewall <NUM>, a base <NUM> (having a surface that projects toward an interior <NUM> of the housing <NUM> or more generally an interior of the lighting unit <NUM>), and what may be characterized as a mounting flange <NUM>. A plurality of supports or standoff <NUM> extend from the base <NUM> and terminate at a proximal or mounting end <NUM> of the lighting unit <NUM>. The mounting flange <NUM> may include both the base <NUM> and the various supports <NUM>. An outer perimeter of the base <NUM> may extend beyond an outer perimeter of the sidewall <NUM> (e.g., to allow one or more fasteners to be directed through the base <NUM> at a location that is beyond the outer perimeter of the sidewall <NUM>, through a corresponding portion of a thermal insulator <NUM> to be discussed below, and into a tail cone of an aircraft). One of the supports <NUM> may extend about the entire outer perimeter of the base <NUM> (spaced outwardly relative to the sidewall <NUM>) and may be characterized as an outer rim for the mounting flange <NUM>.

The proximal end <NUM> of the lighting unit housing <NUM> (or more generally of the lighting unit <NUM>) is oppositely disposed relative to a distal or light output end <NUM> of the lighting unit housing <NUM> (or more generally of the lighting unit <NUM>). As will be discussed in more detail below, the proximal end <NUM> may be disposed in closely-spaced and/or interfacing relation with a tail cone of an aircraft that includes an APU.

Although the lighting unit housing <NUM> has been described in relation to having different portions or components (which could be separately formed and joined together in any appropriate manner for the above-noted arrangement), the lighting unit housing <NUM> may be of an integral or one-piece construction (e.g., without a joint between adjacent portions or components of the lighting unit housing <NUM>). The lighting unit housing <NUM>, including each of the noted portions/components thereof, may be formed from any appropriate material or combination of materials. One or more metals, one or more metal alloys, or any combination thereof may be used for the lighting unit housing <NUM>, for instance aluminum (e.g., the entirety of the lighting unit housing <NUM> may be formed from aluminum). Any appropriate size, shape, and/or configuration may be utilized for the lighting unit housing <NUM>, and thereby including sizes, shapes, and/or configurations different from the illustrated oval configuration of the sidewall <NUM> and more generally the lighting unit housing <NUM>.

The supports <NUM> of the lighting unit housing <NUM> extend from one side of the base <NUM> (e.g., the supports <NUM> extending in a direction of a tail cone surface on which the lighting unit <NUM> is to be installed). One or more light sources (including an associated printed circuit board and/or other electronics) may be disposed on the opposite side of this base <NUM> and as will be discussed in more detail below. As such, the supports <NUM> may be characterized as providing a "standoff" function between the tail cone of an aircraft and the base <NUM> of the lighting unit <NUM> (when the lighting unit <NUM> is installed on an exterior of the aircraft, such as on an end or end surface of a tail cone).

One or more thermal insulators <NUM> extend from the same side of the base <NUM> of the lighting unit housing <NUM> as the above-noted supports or standoffs <NUM> (e.g., the thermal insulators <NUM> extending in a direction of a tail cone surface on which the lighting unit <NUM> is to be installed). The thermal insulators <NUM> may be formed from a different material than at least the supports/standoffs <NUM> (or from a different material than the entirety of the lighting unit housing <NUM>). Representative materials for the thermal insulators <NUM> include without limitation a mica-based laminate (e.g., Cogetherm®), E60 Glass/Epoxy technical composite, Pyrotek NAD <NUM>, and the like. Generally, the thermal insulators <NUM> may be of a material having a low thermal conductivity and a high compressive strength, including at elevated operating temperatures (e.g., <NUM>-<NUM>). Each thermal insulator <NUM> may have a lower thermal conductivity than a thermal conductivity of the supports/standoffs <NUM> (or more generally a lower thermal conductivity than a thermal conductivity of the mounting flange <NUM>). The thermal conductivity of the thermal insulators <NUM> may be at least about <NUM> percent less than the thermal conductivity of the supports/standoffs <NUM> (or the entirety of the mounting flange <NUM>, or the entirety of the lighting unit housing <NUM>, or both) in various embodiments, and may be at least about <NUM> percent less than the thermal conductivity of the supports/standoffs <NUM> (or the entirety of the mounting flange <NUM>, or the entirety of the lighting unit housing <NUM>, or both) in various embodiments.

The proximal or mounting end <NUM> of the lighting unit <NUM> includes a proximal or terminal end of each support/standoff <NUM>, as well as a proximal or terminal end of each thermal insulator <NUM>. The proximal end <NUM> of the lighting unit <NUM> may be an at least substantially flat surface. At least <NUM>% of a surface area of the proximal end <NUM> may be collectively defined by the thermal insulators <NUM> in various embodiments. At least <NUM>% of a surface area of the proximal end <NUM> may be collectively defined by the thermal insulators <NUM> in various embodiments. In either case, the existence of the thermal insulator(s) <NUM> on the proximal or mounting end <NUM> of the lighting unit <NUM> reduces the contact between the mounting flange <NUM> (that includes the supports/standoffs <NUM>) and the structure to which the lighting unit <NUM> is mounted (e.g., a tail cone of an aircraft).

Generally, the mounting flange <NUM> may be characterized as being in the form of a plurality of supports/standoffs <NUM> that are disposed in spaced relation to one another, with a thermal insulator <NUM> occupying each of these open spaces between the various supports/standoffs <NUM>. <FIG> show the supports/standoffs <NUM> as being annular structures, although each support/standoff <NUM> may be of any appropriate size, shape, and/or configuration (e.g., each support/standoff <NUM> could be in the form of a post or the like). "Annular" in relation to the supports/standoffs <NUM> simply means that a given support/standoff <NUM> extends a full <NUM>° about a common point or location or has a "closed perimeter. " Although the supports/standoffs <NUM> are illustrated as being of an oval-shape, other shapes of annular structures for the supports/standoffs <NUM> may be utilized (e.g., square, rectangular, round). Although the supports/standoffs <NUM> are illustrated as being "concentrically" disposed, non-concentrically disposed arrangements for annular supports/standoffs <NUM> are also within the scope of this disclosure. The supports/standoffs <NUM> may be formed in any appropriate manner, including by machining a closed end of the lighting unit housing <NUM> that will end up defining both the supports <NUM> and the noted base <NUM>. In any case, a thermal insulator <NUM> is disposed between each adjacent pair of supports/standoffs <NUM>.

The lighting unit <NUM> may be mounted to the tail cone of an aircraft in any appropriate manner. One or more fasteners may be directed through the mounting flange <NUM> of the lighting unit housing <NUM> (e.g., a portion of the base <NUM> that extends beyond the outer perimeter of the sidewall <NUM>) and into engagement (e.g., threadable engagement) with a given structure (e.g., an aircraft tail cone). One or more fasteners may in fact also extend through an aligned thermal insulator <NUM>. In addition to the noted thermal properties, the thermal insulator <NUM> may also exhibit an acceptable compressive strength, for instance a compressive strength of at least about <NUM> MPA in various embodiments, and/or a compressive strength of at least about <NUM> MPA in various embodiments (e.g., Cogetherm® having a compressive strength of <NUM> MPa). The thermal insulator <NUM> may also allow for a reduction in the overall weight of the lighting unit <NUM>. The thermal insulator <NUM> may have a reduced density compared to a density of the lighting unit housing <NUM>, for instance the density of the thermal insulator <NUM> may be at least <NUM> percent less than a density of the lighting unit housing <NUM> in various embodiments, and/or the density of the thermal insulator <NUM> may be at least <NUM> percent less than a density of the lighting unit housing <NUM> in various embodiments (e.g., Cogetherm® having a density of <NUM>/cm<NUM>, versus aluminum (e.g., a potential material for the lighting unit housing <NUM>) which has a density of <NUM>/cm<NUM>)).

<FIG> illustrates a portion of the interior <NUM> of the lighting unit <NUM> taken along line 3C-3C of <FIG>, and within the most inwardly-disposed annular support/standoff <NUM> shown in <FIG>. A printed circuit board <NUM> is disposed on a side of the base <NUM> of the lighting unit housing <NUM> that is opposite of the side of the base <NUM> from which the supports/standoffs <NUM> and thermal insulators <NUM> extend (e.g., the printed circuit board <NUM> is disposed on a surface of the base <NUM> that projects toward the interior <NUM> of the lighting unit housing <NUM>). Stated another way, the base <NUM> is disposed between the printed circuit board <NUM> and collectively the thermal insulators <NUM> and the supports <NUM>. One or more light sources <NUM> may be positioned on the printed circuit board <NUM>, may be operatively interconnected with the printed circuit board <NUM>, or both. Each light source <NUM> may be of any appropriate size, shape, configuration, and/or type, for instance a light-emitting diode or LED. <FIG> also illustrates a cover or lens <NUM> that is positioned on/defines the distal or light output end <NUM> of the lighting unit <NUM> and that may be of any appropriate shape on the exterior of the lighting unit <NUM>. Light from operation of one or more of the light sources <NUM> is directed through the cover or lens <NUM> (e.g., the cover or lens <NUM> may be formed from any appropriate transparent material or combination of transparent materials).

<FIG> illustrates a representative mounting or attachment of the external lighting unit <NUM> of <FIG> to an aircraft. An aircraft tail cone assembly <NUM> includes a tail cone <NUM> of an aircraft (e.g., aircraft <NUM> of <FIG>; aircraft <NUM> of <FIG>; aircraft <NUM> of <FIG>), along with the above-described exterior aircraft lighting unit <NUM>. An APU <NUM> of any appropriate size, shape, configuration, and/or type (e.g., APU <NUM> of <FIG>) is disposed within the interior of the tail cone <NUM>. Exhaust from the APU <NUM> is discharged from the tail cone <NUM> through an APU exhaust <NUM> on an end section (or a tail cone surface) <NUM> of the tail cone <NUM>. The lighting unit <NUM> is mounted to the end section <NUM> of the tail cone <NUM> at least somewhat in proximity to the APU exhaust <NUM>.

Exhaust from the APU <NUM> heats the tail cone <NUM> of the associated aircraft. The lighting unit <NUM> reduces conductive heat transfer between the tail cone <NUM> and the lighting unit housing <NUM> (particularly the printed circuit board <NUM> within the interior <NUM> of the lighting unit <NUM> and the associated light source(s) <NUM>). This reduction of conductive heat transfer may be characterized as being provided by the reduced contact between the lighting unit housing <NUM> (more specifically the mounting flange <NUM>) and the end section <NUM> of the tail cone <NUM>. That is, incorporating the thermal insulator(s) <NUM> on the proximal or mounting end <NUM> of the lighting unit <NUM> reduces the conductive heat transfer from the tail cone <NUM> to the lighting unit housing <NUM> (more specifically reduces the conductive heat transfer from the tail cone <NUM> to the mounting flange <NUM> and including its base <NUM>), and including reducing the conductive heat transfer from the tail cone <NUM> to the printed circuit board <NUM> and the associated light source(s) <NUM> (the conductive heat transfer being through the lighting unit housing <NUM>, more specifically being through the mounting flange <NUM>). Heating of the printed circuit board <NUM> may adversely impact one or more coatings (e.g., a parylene coating, which may be subject to evaporation due to exposure to elevated temperatures) and that in turn may adversely impact performance of the printed circuited board <NUM> and the associated lighting source(s) <NUM>.

Any feature of any other various aspects addressed in this disclosure that is intended to be limited to a "singular" context or the like will be clearly set forth herein by terms such as "only," "single," "limited to," or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular. Moreover, any failure to use phrases such as "at least one" also does not limit the corresponding feature to the singular. Use of the phrase "at least substantially," "at least generally," or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a surface is at least substantially or at least generally flat encompasses the surface actually being flat and insubstantial variations thereof). Finally, a reference of a feature in conjunction with the phrase "in one embodiment" does not limit the use of the feature to a single embodiment.

The foregoing description has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present disclosure, as long as they fall within the scope of the claims.

Claim 1:
An aircraft tail cone assembly, comprising:
a tail cone (<NUM>, <NUM>); and
a lighting unit (<NUM>) mounted on said tail cone (<NUM>, <NUM>), wherein said lighting unit (<NUM>) comprises:
a lighting unit housing (<NUM>);
at least one light source (<NUM>) disposed within said lighting unit (<NUM>);
a proximal end in closely-spaced relation or interfacing relation with said tail cone (<NUM>, <NUM>);
a mounting flange (<NUM>),
said mounting flange including at least one open space that projects in a direction of said tail cone (<NUM>, <NUM>), wherein said proximal end comprises said mounting flange (<NUM>); and
a thermal insulator (<NUM>), wherein said proximal end further comprises said thermal insulator (<NUM>), wherein said thermal insulator (<NUM>) has a lower thermal conductivity than a thermal conductivity of said mounting flange (<NUM>), and
said thermal insulator (<NUM>) is disposed within each open space of said at least one open space of said mounting flange (<NUM>).