Patent Description:
Gas turbine engines may be employed to power various devices. For example, a gas turbine engine may be employed to propel or supply power to a vehicle, such as an aircraft. Due to the size or configuration of the aircraft, in certain instances, the gas turbine engine may need to be mounted on a side of an airframe of the aircraft. In certain examples, the gas turbine engine may include a thrust reverser, which is deployable to move relative to the gas turbine engine to redirect turbine engine exhaust flow in order to generate reverse thrust to assist in stopping the aircraft. Generally, however, most side mounted gas turbine engines are unable to employ a thrust reverser that moves relative to the gas turbine engine to deploy due to mounting constraints.

Accordingly, it is desirable to provide a pylon structure for coupling a gas turbine engine to a vehicle, such as an aircraft, which enables a thrust reverser associated with the gas turbine engine to move relative to the gas turbine engine to deploy. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Documents cited during prosecution include <CIT>, which discloses a thrust reverser for a turbojet mounted on a pylon, the thrust reverser having a drive device that drives a movable portion in translation relative to a fixed portion, in which a beam or slide comprises a stop projecting on radially outer surface of the beam and having a clearance to the pylon.

According to various embodiments, a pylon system for coupling an engine to a vehicle is provided. The pylon system includes a vehicle pylon configured to be coupled to the vehicle. The vehicle pylon includes a seal along a portion of the vehicle pylon. The pylon system includes an engine pylon including an inboard longeron and an outboard longeron. The inboard longeron is coupled to the outboard longeron at a first end of the engine pylon and is spaced apart from the outboard longeron at a second end of the engine pylon. The inboard longeron is configured to be coupled to the engine, and the engine pylon is slidably coupled to the seal such that the engine pylon is movable relative to the vehicle pylon between at least a first position and a second position.

The engine includes a translating cowl thrust reverser that is movable between at least a first, stowed position and a second, deployed position. The engine pylon is configured to be coupled to the translating cowl thrust reverser of the engine and the engine pylon is configured to move with the translating cowl thrust reverser between at least the first position and the second position. The inboard longeron further comprises a forward seal at the first end. The pylon system includes a vehicle forward seal coupled to the vehicle pylon, and the forward seal is configured to contact the vehicle forward seal in the first position of the engine pylon. At least a portion of the outboard longeron overlaps the inboard longeron at the first end. The pylon system includes at least one spacer coupled to the inboard longeron proximate the outboard longeron to define a uniform exterior surface for the inboard longeron. The inboard longeron includes an inboard seal that extends along the inboard longeron from the first end to the second end. The pylon system includes an engine skin panel coupled to the inboard longeron and the outboard longeron from the first end to the second end, a vehicle skin panel coupled to the vehicle pylon, and the vehicle skin panel is substantially parallel with the engine skin panel. Each of the vehicle skin panel and the engine skin panel define at least one removable access panel. The seal of the vehicle pylon is coupled to the vehicle skin panel. The vehicle pylon includes a vehicle longeron that is coupled to the vehicle skin panel. The inboard longeron includes at least one fastening aperture configured to receive a fastener to couple the inboard longeron to the engine. The at least one fastening aperture includes at least one serrated slot configured to receive the fastener. The seal of the vehicle pylon further comprises a pair of blade seals and the engine pylon is movable relative to the vehicle pylon along the pair of blade seals. The pylon system includes a skin panel coupled to the inboard longeron and the outboard longeron such that the skin panel extends beyond the outboard longeron to define a rail, and the rail is slidably coupled to the seal. The engine is a gas turbine engine and the vehicle is an aircraft.

Also provided is a pylon system for coupling an engine to a vehicle. The pylon system includes a vehicle pylon configured to be coupled to the vehicle. The vehicle pylon includes a vehicle skin panel that defines an exterior surface of the vehicle pylon, and a seal coupled to the vehicle skin panel that extends along a portion of the vehicle pylon. The pylon system includes an engine pylon including an inboard longeron, an outboard longeron and a skin panel that encloses the inboard longeron and the outboard longeron. The inboard longeron is coupled to the outboard longeron at a first end of the engine pylon and spaced apart from the outboard longeron at a second end of the engine pylon. The inboard longeron is configured to be coupled to the engine, and the skin panel is coupled to the outboard longeron to define a rail that is slidably coupled to the seal such that the engine pylon is movable relative to the vehicle pylon between at least a first position and a second position.

The engine includes a translating cowl thrust reverser that is movable between at least a first, stowed position and a second, deployed position, the engine pylon is configured to be coupled to the translating cowl thrust reverser of the engine and the engine pylon is configured to move with the translating cowl thrust reverser between at least the first position and the second position. The inboard longeron includes a forward seal at the first end and an inboard seal that extends along the inboard longeron from the first end to the second end. The vehicle pylon includes a vehicle forward seal coupled to the vehicle pylon, and the forward seal is configured to contact the vehicle forward seal in the first position of the engine pylon. At least a portion of the outboard longeron overlaps the inboard longeron at the first end, and at least one spacer is coupled to the inboard longeron proximate the outboard longeron to define a uniform exterior surface for the inboard longeron.

In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any type of device that would benefit from a pylon system and the use of the pylon system for a side mounted gas turbine engine and a vehicle described herein is merely one exemplary embodiment according to the present disclosure. In addition, while the pylon system is described herein as being used with a gas turbine engine onboard a vehicle, such as a bus, motorcycle, train, automobile, marine vessel, aircraft, rotorcraft and the like, in embodiments not presently being claimed the various teachings of the present disclosure can be used with a gas turbine engine on a stationary platform. Further, it should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure. In addition, while the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that the drawings are merely illustrative and may not be drawn to scale.

As used herein, the term "axial" refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the "axial" direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term "axial" may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the "axial" direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term "radially" as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as "radially" aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms "axial" and "radial" (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominantly in the respective nominal axial or radial direction. As used herein, the term "substantially" denotes within <NUM>% to account for manufacturing tolerances. Also, as used herein, the term "about" denotes within <NUM>% to account for manufacturing tolerances.

With reference to <FIG>, a pylon system <NUM> is shown. In one example, the pylon system <NUM> couples an engine, such as a gas turbine engine <NUM>, to a vehicle, such as an aircraft <NUM>. As will be discussed, the pylon system <NUM> couples the gas turbine engine <NUM> to an airframe <NUM> of the aircraft <NUM>. Generally, the pylon system <NUM> enables the gas turbine engine <NUM> to be side or rear mounted on the aircraft <NUM> while enabling a thrust reverser <NUM> associated with the gas turbine engine <NUM> to move over various positions. Generally, side mounted or rear mounted gas turbine engines <NUM> are located aft of the wings and also above the wings of the aircraft <NUM>. The pylon system <NUM> may be configured as a left hand pylon or a right hand pylon, which may be attached to an empennage or aft section of the airframe <NUM>. In the example of <FIG>, the pylon system <NUM> is configured as a left hand pylon for side mounting the gas turbine engine <NUM>. A right hand pylon for side mounting the gas turbine engine <NUM> comprises a mirror image of the pylon system <NUM> shown in <FIG>. For ease of description, the following discussion will refer to the pylon system <NUM> as a left hand pylon for side mounting the gas turbine engine <NUM>, but it should be understood that a right hand pylon for side mounting a second gas turbine engine <NUM> to the aircraft <NUM> is a mirror image of the pylon system <NUM> shown and described herein.

Generally, the pylon system <NUM> enables the gas turbine engine <NUM> to be mounted on either the left hand side or the right hand side of the airframe <NUM>, aft of the wings. The pylon system <NUM> enables the aircraft <NUM> to employ the gas turbine engine <NUM> with the thrust reverser <NUM>, which improves a stopping power of the aircraft <NUM>, while enabling the thrust reverser <NUM> to move relative to the gas turbine engine <NUM> without interfering with the mounting of the gas turbine engine <NUM> on the airframe <NUM>. In addition, by mounting the gas turbine engine <NUM> on the side of the aircraft <NUM>, a cabin of the aircraft <NUM> is quieter because of the additional distance between passenger seats and the location of the gas turbine engine <NUM>. Further, by side mounting the gas turbine engine <NUM> using the pylon system <NUM>, the aircraft <NUM> has lower wing clearance, and this enables the use of shorter landing gear, which saves weight. In addition, by side mounting the gas turbine engine <NUM> using the pylon system <NUM>, less foreign object debris, such as dirt, dust and sand, is ingested by the gas turbine engine <NUM> during operation.

As the gas turbine engine <NUM> coupled to the pylon system <NUM> is any suitable engine including the thrust reverser <NUM> with a translating cowl or transcowl <NUM>, the gas turbine engine <NUM> and the thrust reverser <NUM> will not be discussed in detail herein. Briefly, <FIG> is a top view of the gas turbine engine <NUM> with the transcowl <NUM> of the thrust reverser <NUM> in a first, stowed position. The gas turbine engine <NUM> typically generates thrust by means of an accelerating mass of gas. Generally, the gas turbine engine <NUM> is substantially encased within an aerodynamically smooth outer covering, such as a nacelle <NUM>. The nacelle <NUM> substantially surrounds the gas turbine engine <NUM> and forms an aerodynamically shaped cavity around a centerline C of the gas turbine engine <NUM>, thereby providing a flow path for engine exhaust flow when generating forward thrust. Generally, ambient air enters the gas turbine engine <NUM> and passes through a fan. A portion of this air is received within a core of the gas turbine engine <NUM> where it is pressurized by one or more compressors associated with the gas turbine engine <NUM>, and mixed with fuel and ignited within a combustion chamber associated with the gas turbine engine <NUM>. The combustion of the pressurized air and fuel generates combustion products or hot gases known as core flow. The remainder of the air from the fan bypasses the core of the gas turbine engine <NUM> and is known as fan flow. Together, the core flow and the fan flow mix downstream to form the engine exhaust flow that is discharged from the gas turbine engine <NUM>, generating forward thrust.

The thrust reverser <NUM> includes a stationary support structure and the transcowl <NUM>. The support structure couples the thrust reverser <NUM> to the gas turbine engine <NUM>. In this example, the transcowl <NUM> is axially translatable by an actuator relative to the support structure, and thus the gas turbine engine <NUM>, between the first, stowed position, which is the position depicted in <FIG>, a second, deployed position, which is the position depicted in <FIG>, and a third, overstowed position, a detailed cross-section of which depicted in <FIG>. In the first, stowed position, a leading edge <NUM> of the transcowl <NUM> is adjacent to, proximate or abuts the nacelle <NUM>, and in the second, deployed position, the leading edge <NUM> of the transcowl <NUM> is displaced or spaced apart from the nacelle <NUM> to form an aperture <NUM> between the transcowl <NUM> and the nacelle <NUM>. In the third, overstowed position, the leading edge <NUM> compresses a portion of the pylon system <NUM> and a gap between the leading edge <NUM> and the nacelle <NUM> is less than the gap between the leading edge <NUM> and the nacelle <NUM> in the first, stowed position shown in <FIG>. The actuator associated with the transcowl <NUM> is in communication with a controller associated with the gas turbine engine <NUM> or the aircraft <NUM> and is responsive to one or more control signals to move the transcowl <NUM> between the first, stowed position, the second, deployed position and the third, overstowed position. The movement of the transcowl <NUM> moves doors coupled to the transcowl <NUM> to redirect at least a portion of the engine exhaust flow through the aperture <NUM> to generate reverse thrust.

As shown in <FIG>, the pylon system <NUM> includes an engine pylon <NUM> and a vehicle pylon <NUM>. The pylon system <NUM> enables the transcowl <NUM> to move linearly relative to the gas turbine engine <NUM> and the aircraft <NUM> between the first, stowed position, the second, deployed position and the third, overstowed position. In the first, stowed position of the transcowl <NUM>, the engine pylon <NUM> is in a first position (<FIG> and <FIG>) relative to the vehicle pylon <NUM>. In the second, deployed position of the transcowl <NUM>, the engine pylon <NUM> is in a second position (<FIG> and <FIG>) relative to the vehicle pylon <NUM>. In the third, overstowed position of the transcowl <NUM>, the engine pylon <NUM> is in a third position (<FIG>) relative to the vehicle pylon <NUM>. With reference to <FIG>, the engine pylon <NUM> is shown. The engine pylon <NUM> movably couples the transcowl <NUM> of the gas turbine engine <NUM> to the vehicle pylon <NUM> (<FIG>). In addition, as will be discussed, the engine pylon <NUM> enables the transcowl <NUM> of the gas turbine engine <NUM> to be adjustably coupled to the vehicle pylon <NUM>. By enabling the adjustment of the gas turbine engine <NUM> relative to the vehicle pylon <NUM>, a location and orientation of the gas turbine engine <NUM> relative to the airframe <NUM> (<FIG>) is adjustable to account for manufacturing tolerances, which reduces aerodynamic drag by enabling the alignment of the engine pylon <NUM> with the airframe <NUM> (<FIG>).

With reference to <FIG>, an exploded view of the engine pylon <NUM> is shown. In one example, the engine pylon <NUM> includes a first, inboard longeron <NUM>, a second, outboard longeron <NUM>, a forward seal <NUM>, at least one elongated seal <NUM>, at least one fastening assembly <NUM>, at least one spacer <NUM> and a skin panel <NUM>. The inboard longeron <NUM> is composed of a polymer-based material, metal, or metal alloy, and is cast, stamped, machined, additively manufactured, etc. In this example, the inboard longeron <NUM> has a triangular shape, with a first base <NUM> defined at a first end 130a, and a first apex <NUM> defined at a second end 130b. The inboard longeron <NUM> also has a first side 130c opposite a second side 130d. The inboard longeron <NUM> is substantially solid at the first base <NUM> and the first apex <NUM>, but defines a plurality of cut-outs <NUM> between the first base <NUM> and the first apex <NUM>. In this example, the inboard longeron <NUM> defines three cut-outs 148a-148c. The cut-outs 148a-148c reduce a mass associated with the inboard longeron <NUM>. The inboard longeron <NUM> also defines a first flange <NUM>, a second flange <NUM> opposite the first flange <NUM>, and at least one or a plurality of fastening apertures <NUM>.

With brief reference to <FIG>, the inboard longeron <NUM> extends along a longitudinal axis L, which is a center line for the inboard longeron <NUM>, and the first flange <NUM> and the second flange <NUM> extend along an axis transverse or oblique to the longitudinal axis L. In one example, the first flange <NUM> extends at an angle α relative to the longitudinal axis L and the second flange <NUM> extends at a negative of the angle α relative to the longitudinal axis L. The angle α is about <NUM> degrees to about <NUM> degrees. The first flange <NUM> and the second flange <NUM> extend outwardly from the first base <NUM> at the first end 130a to the first apex <NUM> at the second end 130b. The first flange <NUM> and the second flange <NUM> are defined along opposite outboard edges 153a, 153b of the inboard longeron <NUM> and extend outwardly from the first side 130c. With reference back to <FIG>, generally, the first flange <NUM> and the second flange <NUM> are spaced apart at the first apex <NUM> to enable the receipt of mechanical fasteners proximate the first apex <NUM> to couple the skin panel <NUM>, the spacer <NUM> and the elongated seal <NUM> to the inboard longeron <NUM>. In addition, the space defined between the first flange <NUM> and the second flange <NUM> at the first apex <NUM> enables the at least one elongated seal <NUM> to be positioned between the first flange <NUM> and the second flange <NUM> at the first apex <NUM>. The first flange <NUM> includes a chamfer <NUM> that extends for a distance D from the first end 130a. In one example, the distance D is about <NUM> to about <NUM> (about <NUM> inches to about <NUM> inches) and is about the same or greater than a width W of a second base <NUM> of the outboard longeron <NUM>. By defining the chamfer <NUM> for the distance D, when the inboard longeron <NUM> is coupled to the outboard longeron <NUM>, the second end 130b of the inboard longeron <NUM> is angled outward or away from the outboard longeron <NUM>. From the chamfer <NUM> to the first apex <NUM>, the first flange <NUM> defines a plurality of spaced apart holes <NUM>. Each of the holes <NUM> is configured to receive a fastener, such as a rivet, therethrough to couple the elongated seal <NUM>, the spacer <NUM> and the skin panel <NUM> to the first flange <NUM>. The second flange <NUM> defines a plurality of spaced apart second holes <NUM>. Each of the second holes <NUM> is configured to receive a fastener, such as a rivet, therethrough to couple the elongated seal <NUM>, the spacer <NUM> and the skin panel <NUM> to the second flange <NUM>. The spacing of the holes <NUM> and the second holes <NUM> is generally predetermined to provide additional stability for the elongated seal <NUM>. Generally, the inboard longeron <NUM> and the outboard longeron <NUM> are triangular in shape to correspond with the shape of the vehicle pylon <NUM>. It should be noted that the shape of the inboard longeron <NUM> and the outboard longeron <NUM> may vary to correspond with different vehicle pylon shapes. The angle α is also generally predetermined based on the vehicle pylon <NUM>, and may be different for different vehicle pylon shapes.

The fastening apertures <NUM> couple the inboard longeron <NUM> to the transcowl <NUM> of the gas turbine engine <NUM> (<FIG>). In this example, the inboard longeron <NUM> includes three fastening apertures 154a-154c, with two of the fastening apertures 154a, 154b defined proximate the first base <NUM> and the fastening aperture 154c defined proximate the first apex <NUM>. Each of the fastening apertures 154a-154c are the same, and thus, a single fastening aperture 154a will be discussed in detail herein. With reference to <FIG>, in one example, the fastening aperture 154a includes at least one or a pair of fastening slots <NUM> and a central bore <NUM>. The fastening slots <NUM> are defined so as to be spaced apart from the central bore <NUM> and opposite each other about the central bore <NUM>. Each of the fastening slots <NUM> are elongated along an axis that is substantially perpendicular to the longitudinal axis L. Each of the fastening slots <NUM> define a plurality of slot serrations <NUM> about a perimeter of the fastening slot <NUM> on the second side 130d of the inboard longeron <NUM>. The slot serrations <NUM> cooperate with a serrated washer <NUM> associated with a mechanical fastener <NUM> to enable a vertical position of the inboard longeron <NUM>, and thus, the engine pylon <NUM> to be adjusted relative to the vehicle pylon <NUM> (<FIG>). The slot serrations <NUM> are spaced apart in any predetermined pattern to define a plurality of defined positions for coupling the mechanical fastener <NUM> to the inboard longeron <NUM>. In this example, the mechanical fastener <NUM> is the bolt <NUM> associated with the locking positioning system <NUM> of commonly assigned <CIT> (Attorney Docket No. H223712-<CIT>US)) titled "Locking Positioning Systems" to Alstad. The central bore <NUM> is sized to enable a portion of the locking positioning system <NUM> to be positioned through the inboard longeron <NUM> to be coupled to the transcowl <NUM> (<FIG>). It should be noted that the use of the locking positioning system <NUM> for adjustably coupling the inboard longeron <NUM> to the transcowl <NUM> is merely an example, as other mechanical fasteners may be employed and the fastening apertures 154a-154c may be modified to accommodate these mechanical fasteners. Moreover, a combination of locking positioning systems <NUM> and mechanical fasteners may be employed such that the inboard longeron <NUM> may not be coupled to the transcowl <NUM> via three locking positioning systems <NUM> as shown in <FIG>.

With reference to <FIG>, the outboard longeron <NUM> is coupled to the inboard longeron <NUM>. The outboard longeron <NUM> is composed of a polymer-based material, metal, or metal alloy, and is cast, stamped, machined, additively manufactured, etc. In this example, the outboard longeron <NUM> has a triangular shape, with the second base <NUM> defined at a first end 132a, and a second apex <NUM> defined at a second end 132b. The outboard longeron <NUM> also has a first side 132c opposite a second side 132d. The second base <NUM> of the outboard longeron <NUM> is coupled to the first base <NUM> of the inboard longeron <NUM>, and the second apex <NUM> is spaced apart from the first apex <NUM> of the inboard longeron <NUM>. The outboard longeron <NUM> is substantially solid at the second base <NUM> and the second apex <NUM>, but defines a plurality of cut-outs <NUM> between the second base <NUM> and the second apex <NUM>. In this example, the outboard longeron <NUM> defines four cut-outs 174a-174d. The cut-outs 174a-174d reduce a mass associated with the outboard longeron <NUM>. The outboard longeron <NUM> also defines a first outboard flange <NUM> and a second outboard flange <NUM> opposite the first outboard flange <NUM>.

With brief reference to <FIG>, the outboard longeron <NUM> extends along a longitudinal axis L1, which is a center line for the outboard longeron <NUM>, and the first outboard flange <NUM> and the second outboard flange <NUM> extend along an axis transverse or oblique to the longitudinal axis L1. The longitudinal axis L of the inboard longeron <NUM> is oblique to the longitudinal axis L1 of the outboard longeron <NUM>. In one example, the first outboard flange <NUM> extends at an angle β relative to the longitudinal axis L1 and the second outboard flange <NUM> extends at a negative of the angle β relative to the longitudinal axis L1. The angle β is about <NUM> degrees to about <NUM> degrees. The first outboard flange <NUM> and the second outboard flange <NUM> extend outwardly from the second base <NUM> at the first end 132a to the second apex <NUM> at the second end 132b. The first outboard flange <NUM> and the second outboard flange <NUM> are defined along opposite outboard edges 179a, 179b of the outboard longeron <NUM> and extend outwardly from the first side 132c (<FIG>). With reference back to <FIG>, generally, the first outboard flange <NUM> and the second outboard flange <NUM> are spaced apart at the second apex <NUM> to enable the receipt of mechanical fasteners, such as rivets, proximate the second apex <NUM> to couple the skin panel <NUM> to the outboard longeron <NUM>.

The first outboard flange <NUM> includes a projection <NUM>. The projection <NUM> is triangular, and has a projection base 180a that extends outwardly from the first outboard flange <NUM>. An edge 180b of the projection <NUM> tapers from the projection base 180a to the second apex <NUM>. The projection <NUM> is sized to overlap or overlie a portion of the first flange <NUM> of the inboard longeron <NUM> at the first end 130a. The projection <NUM> also includes projection holes <NUM> to receive mechanical fasteners to couple the outboard longeron <NUM> to the inboard longeron <NUM> at the respective first end 130a, 132a. The projection <NUM> extends for a distance D2 from the first end 132a. In one example, the distance D2 is about <NUM> inches (in. ) to about <NUM> inches (in. By defining the projection <NUM> for the distance D2, the outboard longeron <NUM> reinforces the inboard longeron <NUM> at the first end 130a and proximate the fastening apertures <NUM> when the inboard longeron <NUM> is coupled to the outboard longeron <NUM>. From the projection <NUM> to the second apex <NUM>, the first outboard flange <NUM> defines a plurality of spaced apart bores <NUM>. Each of the bores <NUM> is configured to receive a fastener, such as a rivet, therethrough to couple the skin panel <NUM> to the first outboard flange <NUM>. In this example, an interior surface 176a of the first outboard flange <NUM> includes a plurality of nut plates <NUM>. Each of the nut plates <NUM> is coupled to the interior surface 176a via rivets, for example, and is coaxial to a respective one of the bores <NUM>. The nut plates <NUM> receive the rivet inserted into the respective bore <NUM> to couple the skin panel <NUM> to the outboard longeron <NUM>.

The second outboard flange <NUM> includes a second projection <NUM>. The second projection <NUM> is triangular, and has a second projection base 190a that extends outwardly from the second outboard flange <NUM>. An edge 190b of the second projection <NUM> tapers from the second projection base 190a to the second apex <NUM>. The second projection <NUM> is sized to overlap or overlie a portion of the second flange <NUM> of the inboard longeron <NUM> at the first end 130a. The second projection <NUM> also includes second projection holes <NUM> to receive mechanical fasteners to couple the outboard longeron <NUM> to the inboard longeron <NUM> at the respective first end 130a, 132a. The second projection <NUM> extends for the distance D2 from the first end 132a. By defining the second projection <NUM> for the distance D2, the outboard longeron <NUM> reinforces the inboard longeron <NUM> at the first end 130a and proximate the fastening apertures <NUM> when the inboard longeron <NUM> is coupled to the outboard longeron <NUM>. From the second projection <NUM> to the second apex <NUM>, the second outboard flange <NUM> defines a plurality of spaced apart second bores <NUM>. Each of the second bores <NUM> is configured to receive a fastener, such as a rivet, therethrough to couple the skin panel <NUM> to the second outboard flange <NUM>. In this example, an interior surface 178a of the second outboard flange <NUM> includes a plurality of second nut plates <NUM>. Each of the second nut plates <NUM> is coupled to the interior surface 172a via rivets, for example, and is coaxial to a respective one of the second bores <NUM>. The second nut plates <NUM> receive the rivet inserted into the respective second bore <NUM> to couple the skin panel <NUM> to the outboard longeron <NUM>.

The forward seal <NUM> creates a seal between the transcowl <NUM> and the engine pylon <NUM> (<FIG>). The forward seal <NUM> is composed of an elastomeric material, and is cast, molded, etc. The forward seal <NUM> has a first seal surface <NUM> opposite a second seal surface <NUM>, and a first seal end <NUM> opposite a second seal end <NUM>. In one example, the first seal surface <NUM> has a concave curvature to comport with the curvature of the transcowl <NUM> (<FIG>) and to assist in forming a seal against the surface of the transcowl <NUM> (<FIG>). The second seal surface <NUM> is substantially planar to mate against a surface of the first base <NUM> of the inboard longeron <NUM>. In one example, seal fastening bores <NUM> are defined through the first seal surface <NUM> and the second seal surface <NUM> to couple the forward seal <NUM> to the inboard longeron <NUM> and the outboard longeron <NUM>. Corresponding seal fastening bores <NUM> are defined in the first base <NUM> of the inboard longeron <NUM> and seal fastening bores <NUM> are defined in the second base <NUM> of the outboard longeron <NUM> (<FIG>). Mechanical fasteners, such as screws, are inserted through the seal fastening bores <NUM>, <NUM> and seal fastening bores <NUM> to couple the forward seal <NUM> to the inboard longeron <NUM> and the outboard longeron <NUM>. Generally, the forward seal <NUM> is coupled to the inboard longeron <NUM> and the outboard longeron <NUM> such that the forward seal <NUM> extends beyond the first end 130a of the inboard longeron <NUM> and the first end 132a of the outboard longeron <NUM>. It should be noted that the forward seal <NUM> may be coupled to the inboard longeron <NUM> and/or the outboard longeron <NUM> via any technique, including, but not limited to, adhesives. With reference to <FIG>, the first seal end <NUM> is coupled and positioned adjacent to a surface 150a of the first flange <NUM> of the inboard longeron <NUM>. The second seal end <NUM> is coupled and positioned adjacent to a surface 152a of the second flange <NUM> of the inboard longeron <NUM>.

In this example, the at least one elongated seal <NUM> comprises a pair of elongated seals 136a, 136b. The pair of elongated seals 136a, 136b are coupled to the first flange <NUM> and the second flange <NUM>, respectively, to extend from the forward seal <NUM> to the first apex <NUM>. Each elongated seal 136a, 136b is composed of an elastomeric material, and is extruded, cast, molded, etc. Each of the elongated seals 136a, 136b is the same, and includes a first elongated end <NUM> opposite a second elongated end <NUM>, a bulb <NUM> and a fastening strip <NUM> (<FIG>). The first elongated end <NUM> of the elongated seal 136a is positioned adjacent to the first seal end <NUM> of the forward seal <NUM> and extends from the forward seal <NUM> to the first apex <NUM>. The first elongated end <NUM> of the elongated seal 136b is positioned adjacent to the second seal end <NUM> of the forward seal <NUM> and extends from the forward seal <NUM> to the first apex <NUM>. The second elongated end <NUM> of the elongated seals 136a, 136b is coupled to the first apex <NUM>. With reference back to <FIG>, the bulb <NUM> has an oval cross-section, and extends outwardly from the elongated seal 136a, 136b to provide sealing against the transcowl <NUM> (<FIG>). The fastening strip <NUM> is defined adjacent to the bulb <NUM>, and extends from the first elongated end <NUM> to the second elongated end <NUM>. The fastening strip <NUM> is planar, and includes spaced apart seal holes <NUM>. The seal holes <NUM> are coaxially aligned with respective ones of the holes <NUM> and the second holes <NUM> to couple the elongated seals 136a, 136b to the respective one of the first flange <NUM> and the second flange <NUM>.

In this example, the at least one fastening assembly <NUM> comprises a pair of fastening assemblies 138a, 138b. In one example, each of the fastening assemblies 138a, 138b is a nut plate strip, which includes a plurality of nut plates <NUM> fixedly coupled to an elongated body <NUM>. Each of the nut plates <NUM> and the bodies <NUM> are composed of a metal or metal alloy, and are stamped, cast, forged, additively manufactured, etc. The nut plates <NUM> are generally formed discretely from the respective body <NUM>, and are coupled to the respective body <NUM> via rivets, for example. Each nut plate <NUM> is coaxial with a hole <NUM> defined through the body <NUM>. Each body <NUM> has a first body end <NUM> opposite a second body end <NUM>. The first body end <NUM> is coupled adjacent to the forward seal <NUM>, and the second body end <NUM> extends to the first apex <NUM>. The fastening assembly 138a extends along the first flange <NUM>, and the fastening assembly 138b extends along the second flange <NUM>. As will be discussed, the fastening assemblies 138a, 138b enable the respective the elongated seal 136a, 136b, the spacer <NUM>, and the skin panel <NUM> to be coupled to the respective first flange <NUM> and the second flange <NUM>.

In this example, the at least one spacer <NUM> comprises a pair of spacers 140a, 140b. The spacers 140a, 140b are composed of a metal or metal alloy, and are stamped, cast, machined, additively manufactured, etc. The spacers 140a, 140b comprise elongated strips, which extend from proximate the respective projection <NUM> and second projection <NUM> along the respective first flange <NUM> and second flange <NUM> to the respective first apex <NUM> and second apex <NUM> to provide a uniform surface for the skin panel <NUM>. Stated another way, the spacers 140a, 140b have a thickness which is substantially equal to a thickness of the projection <NUM> and the second projection <NUM> to define a smooth coupling surface along the inboard longeron <NUM> for the skin panel <NUM>. Each of the spacers 140a, 140b defines a plurality of coupling holes <NUM> that are spaced apart along the spacer 140a, 140b. The coupling holes <NUM> are coaxially aligned with respective holes <NUM> of the fastening assemblies 138a, 138b.

The skin panel <NUM> is coupled to the inboard longeron <NUM> and the outboard longeron <NUM> to define a smooth exterior surface for the engine pylon <NUM>. The skin panel <NUM> is composed of a polymer-based material, metal, or metal alloy, and is stamped, machined, cast, additively manufactured, etc. The skin panel <NUM> includes a first skin panel surface <NUM> and a second skin panel surface <NUM>, which are interconnected by a fold or bend <NUM>. The first skin panel surface <NUM> is coupled along the first flange <NUM> of the inboard longeron <NUM> and the first outboard flange <NUM> of the outboard longeron <NUM> to define an exterior surface along a top of the engine pylon <NUM>. The second skin panel surface <NUM> is coupled along the second flange <NUM> of the inboard longeron <NUM> and the second outboard flange <NUM> of the outboard longeron <NUM> to define an exterior surface along a bottom of the engine pylon <NUM>. The bend <NUM> interconnects the first skin panel surface <NUM> with the second skin panel surface <NUM> and encloses the engine pylon <NUM> at the first apex <NUM> and the second apex <NUM>. Thus, the skin panel <NUM> substantially surrounds the inboard longeron <NUM> and the outboard longeron <NUM> and substantially encloses the engine pylon <NUM>.

The first skin panel surface <NUM> and the second skin panel surface <NUM> each include a plurality of skin panel bores <NUM>. The skin panel bores <NUM> are defined through the skin panel <NUM> for receipt of a mechanical fastener, such as a rivet <NUM> (<FIG>), to couple the skin panel <NUM> to the inboard longeron <NUM> and outboard longeron <NUM>. The skin panel bores <NUM> of the first skin panel surface <NUM> are coaxially aligned with a respective one of the holes <NUM> of the first flange <NUM>, the coupling holes <NUM> of the spacer 140a, the seal holes <NUM> of the elongated seal 136a, the projection holes <NUM> of the projection <NUM>, and the holes <NUM> of the fastening assembly 138a; and the bores <NUM> of the first outboard flange <NUM>. The skin panel bores <NUM> of the second skin panel surface <NUM> are coaxially aligned with a respective one of the second holes <NUM> of the second flange <NUM>, the coupling holes <NUM> of the spacer 140b, the seal holes <NUM> of the elongated seal 136b, the second projection holes <NUM> of the second projection <NUM>, and the holes <NUM> of the fastening assembly 138b; and the second bores <NUM> of the second outboard flange <NUM>.

In one example, with reference to <FIG>, where the projection <NUM> overlies the first flange <NUM>, the rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the first skin panel surface <NUM>, the projection holes <NUM> of the projection <NUM>, the seal holes <NUM> of the elongated seal 136a, the holes <NUM> of the fastening assembly 138a and are secured to the respective one of the nut plates <NUM>. Where the spacer 140a overlies the first flange <NUM>, the rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the first skin panel surface <NUM>, the coupling holes <NUM> of the spacer 140a, the seal holes <NUM> of the elongated seal 136a, the holes <NUM> of the fastening assembly 138a and are secured to the respective one of the nut plates <NUM>. Where the second projection <NUM> overlies the second flange <NUM>, the rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the second skin panel surface <NUM>, the second projection holes <NUM> of the second projection <NUM>, the seal holes <NUM> of the elongated seal 136b, the holes <NUM> of the fastening assembly 138b and are secured to the respective one of the nut plates <NUM>. Where the spacer 140b overlies the second flange <NUM>, the rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the second skin panel surface <NUM>, the coupling holes <NUM> of the spacer 140b, the seal holes <NUM> of the elongated seal 136b, the holes <NUM> of the fastening assembly 138b and are secured to the respective one of the nut plates <NUM>. Generally, with reference to <FIG>, the first skin panel surface <NUM> and the second skin panel surface <NUM> are sized such that a portion of the first skin panel surface <NUM> and the second skin panel surface <NUM> are each cantilevered over the outboard longeron <NUM> to define a first rail and a second rail, indicated by reference numerals 239a, 239b, respectively. In one example, the first skin panel surface <NUM> and the second skin panel surface <NUM> extend a distance DR beyond the second side 132d of the outboard longeron <NUM>. The distance DR is about <NUM> to about <NUM> (about <NUM> inches to about <NUM> inches). The first rail 239a and the second rail 239b defined by the respective portion of the first skin panel surface <NUM> and the second skin panel surface <NUM> that overhangs the outboard longeron <NUM> enables the engine pylon <NUM> to move relative to the vehicle pylon <NUM>, as will be discussed.

With reference back to <FIG>, the second skin panel surface <NUM> defines an access opening <NUM>, which is enclosed with a removable access panel <NUM>. The access opening <NUM> is defined proximate the bend <NUM> to provide access to the fastening aperture 154c to enable adjustment of the coupling between the engine pylon <NUM> and the transcowl <NUM> during installation and use. The access opening <NUM> is generally sized to enable an operator to insert their hand and manipulate the fastening device coupled to the fastening aperture 154c, such as the locking positioning system <NUM>, previously incorporated by reference herein. The access panel <NUM> is composed of a polymer-based material, metal, or metal alloy, and is stamped, machined, cast, additively manufactured, etc. The access panel <NUM> is coupled to the access opening <NUM> via press-fit, mechanical fasteners, etc. Generally, the access panel <NUM> is coupled to the access opening <NUM> to be removable for maintenance, but secured during operation of the aircraft <NUM> (<FIG>).

With reference to <FIG>, the vehicle pylon <NUM> is shown in greater detail. In <FIG>, the engine pylon <NUM> has been removed for clarity. In one example, the vehicle pylon <NUM> includes a vehicle or airframe longeron <NUM>, a forward seal assembly <NUM>, at least one seal fastening assembly <NUM>, at least one seal <NUM>, at least one vehicle or airframe rib <NUM>, at least one vehicle or airframe beam <NUM> and at least one vehicle skin panel or skin panel <NUM>. With reference to <FIG>, the airframe longeron <NUM> is composed of polymer-based material, metal, or metal alloy, and is cast, forged, stamped, additively manufactured, etc. The airframe longeron <NUM> has a triangular shape, with an airframe base <NUM> defined at a first end 300a, and an airframe apex <NUM> defined at a second end 300b. The airframe longeron <NUM> also has a first side 300c opposite a second side 300d. The airframe longeron <NUM> is substantially solid at the airframe base <NUM> and the airframe apex <NUM>, but defines a plurality of cut-outs <NUM> between the airframe base <NUM> and the airframe apex <NUM>. In this example, the airframe longeron <NUM> defines three cut-outs 324a-324c. The cut-outs 324a-324c reduce a mass associated with the airframe longeron <NUM>. The airframe longeron <NUM> also defines a first airframe flange <NUM> and a second airframe flange <NUM> opposite the first airframe flange <NUM>.

With brief reference to <FIG>, the airframe longeron <NUM> extends along a longitudinal axis L2, which is a center line for the airframe longeron <NUM>, and the first airframe flange <NUM> and the second airframe flange <NUM> extend along an axis transverse or oblique to the longitudinal axis L2. In one example, the first airframe flange <NUM> extends at an angle γ relative to the longitudinal axis L2 and the second airframe flange <NUM> extends at a negative of the angle γ relative to the longitudinal axis L2. The angle γ is about <NUM> degrees to about <NUM> degrees. With reference back to <FIG>, the first airframe flange <NUM> and the second airframe flange <NUM> extend outwardly from the airframe base <NUM> at the first end 300a to the airframe apex <NUM> at the second end 300b. The first airframe flange <NUM> and the second airframe flange <NUM> are defined along opposite edges 330a, 330b of the airframe longeron <NUM> and extend outwardly from the second side 300d (<FIG>). Generally, the first airframe flange <NUM> and the second airframe flange <NUM> are spaced apart at the airframe apex <NUM> to enable the receipt of mechanical fasteners proximate the airframe apex <NUM> to couple the seal <NUM> and the skin panel <NUM> to the airframe longeron <NUM>.

The first airframe flange <NUM> defines a plurality of spaced apart airframe bores <NUM> from the airframe base <NUM> to the airframe apex <NUM>. Each of the airframe bores <NUM> is configured to receive a fastener, such as a rivet <NUM> (<FIG>), therethrough to couple the skin panel <NUM> to the first airframe flange <NUM>. In one example, the fastener is the rivet <NUM>, however, any suitable fastener may be used. In this example, an interior surface 326a of the first airframe flange <NUM> includes a plurality of airframe nut plates <NUM> (<FIG>). Each of the airframe nut plates <NUM> is coupled to the interior surface 326a via rivets, for example, and is coaxial to a respective one of the airframe bores <NUM>. The airframe nut plates <NUM> receive the end of the rivet <NUM> inserted into the respective airframe bore <NUM> to couple the skin panel <NUM> to the airframe longeron <NUM>. The first airframe flange <NUM> also defines at least one rib protrusion <NUM>. In this example, the first airframe flange <NUM> defines two rib protrusions 336a, 336b, which correspond with a respective one of the two airframe ribs 308a, 308b. The rib protrusions 336a, 336b each extend outwardly from the first airframe flange <NUM> and define a rib coupling bore <NUM> for coupling the respective airframe rib 308a, 308b to the airframe longeron <NUM>.

With reference to <FIG>, the second airframe flange <NUM> defines a plurality of spaced apart second airframe bores <NUM> from the airframe base <NUM> to the airframe apex <NUM>. Each of the second airframe bores <NUM> is configured to receive the rivet <NUM> therethrough to couple the skin panel <NUM> to the second airframe flange <NUM>. In this example, nut plates (not shown) may be used to secure the rivet <NUM> to the second airframe flange <NUM> during assembly, and thus, couple the skin panel <NUM> to the airframe longeron <NUM>.

With reference back to <FIG>, the forward seal assembly <NUM> includes a vehicle or airframe forward seal <NUM> and a seal bracket <NUM>. The airframe forward seal <NUM> creates a seal between the engine pylon <NUM> and the vehicle pylon <NUM> (<FIG>). The airframe forward seal <NUM> is composed of an elastomeric material, and is cast, molded, etc. The airframe forward seal <NUM> has a first airframe seal surface <NUM> opposite a second airframe seal surface <NUM>, and a first airframe seal end <NUM> opposite a second airframe seal end <NUM>. The airframe forward seal <NUM> also includes a first seal side <NUM> opposite a second seal side <NUM>. In one example, the first airframe seal surface <NUM> faces aft or toward the airframe apex <NUM> and seals against the engine pylon <NUM> in the first, stowed position (<FIG>). The first airframe seal surface <NUM> and the second airframe seal surface <NUM> are generally smooth and planar. The second airframe seal surface <NUM> is coupled to the seal bracket <NUM>. The first airframe seal end <NUM> is positioned adjacent to the first airframe flange <NUM> of the airframe longeron <NUM>. The second airframe seal end <NUM> is positioned adjacent to the second airframe flange <NUM> of the airframe longeron <NUM>. The first airframe seal end <NUM> and the second airframe seal end <NUM> each define a recess <NUM> for coupling the at least one seal <NUM> to the forward seal assembly <NUM>. The coupling of the at least one seal <NUM> to the airframe forward seal <NUM> ensures that the at least one seal <NUM> remains in contact with the engine pylon <NUM> over an entirety of the vehicle pylon <NUM>. The first seal side <NUM> has a concave curvature to assist in forming a seal against the nacelle <NUM> (<FIG>). The second seal side <NUM> is substantially planar to mate against a surface of the airframe base <NUM>.

The seal bracket <NUM> couples the airframe forward seal <NUM> to the airframe longeron <NUM> (<FIG>). The seal bracket <NUM> is composed of polymer-based material, metal, or metal alloy, and is cast, stamped, machined, additively manufactured, etc. In one example, the seal bracket <NUM> is L-shaped, and includes a seal portion <NUM> and a coupling portion <NUM>. The seal portion <NUM> is substantially normal to the coupling portion <NUM>. The seal portion <NUM> is coupled to the airframe forward seal <NUM> and is planar. In one example, the airframe forward seal <NUM> is coupled to the seal bracket <NUM> via nut plates that are attached to the seal bracket <NUM>. The nut plates are attached to the seal bracket <NUM> via riveting, for example. The rivets are then used to secure the airframe forward seal <NUM> to the seal bracket <NUM>. The coupling portion <NUM> is coupled to the airframe base <NUM> and is planar. In one example, the coupling portion <NUM> is coupled to the airframe base <NUM> via welding, however, adhesives, mechanical fasteners and the like may be used.

In one example, with reference to <FIG>, the at least one seal fastening assembly <NUM> includes two seal fastening assemblies 304a, 304b. In one example, each of the seal fastening assemblies 304a, 304b is a nut plate strip, which includes a plurality of seal nut plates <NUM> fixedly coupled to an elongated body <NUM>. Each of the seal nut plates <NUM> and the bodies <NUM> are composed of a metal or metal alloy, and are stamped, cast, forged, additively manufactured, etc. The seal nut plates <NUM> are generally formed discretely from the bodies <NUM>, and are coupled to the bodies <NUM> via welding, for example. Each seal nut plates <NUM> is coaxial with a hole <NUM> defined through the body <NUM>. Each body <NUM> has a first body end <NUM> opposite a second body end <NUM>. The first body end <NUM> is coupled to the at least one seal <NUM> proximate the airframe forward seal <NUM>, and the second body end <NUM> extends to proximate the airframe apex <NUM>. The seal fastening assembly 304a extends next to, proximate or along the first side 300c proximate the first airframe flange <NUM>, and the seal fastening assembly 304b extends next to, proximate or along the first side 300c proximate the second airframe flange <NUM>. As will be discussed, the seal fastening assemblies 304a, 304b enable the at least one seal <NUM> to be coupled to the at least one skin panel <NUM>.

In this example, the at least one seal <NUM> comprises two seals 306a, 306b. Each seal 306a, 306b is composed of an elastomeric material, and is extruded, cast, molded, etc. Each of the seals 306a, 306b is the same, and includes a blade seal <NUM> and a fastening strip <NUM> that each extend from a first seal end <NUM> to a second seal end <NUM>. The first seal end <NUM> of each of the seals 306a, 306b is coupled to the at least one skin panel <NUM> and the second seal end <NUM> of the airframe forward seal <NUM> to extend from the airframe forward seal <NUM> to at or beyond the airframe apex <NUM>. The blade seal <NUM> extends outwardly from the fastening strip <NUM> and is substantially planar. Generally, with reference to <FIG>, the blade seal <NUM> extends a distance DB beyond the at least one skin panel <NUM> to contact the first skin panel surface <NUM> and the second skin panel surface <NUM>. In one example, the distance DB is about <NUM> to about <NUM> (about <NUM> inches to about <NUM> inches). A surface 390a of each blade seal <NUM> is positioned against and in contact with the first skin panel surface <NUM> and the second skin panel surface <NUM> of the engine pylon <NUM>, respectively, and enables the first skin panel surface <NUM> and the second skin panel surface <NUM> to move or slide along each of the blade seals <NUM> as the engine pylon <NUM> moves relative to the vehicle pylon <NUM> (<FIG>), as will be discussed. The fastening strip <NUM> includes a plurality of spaced apart seal bores <NUM> that extend through the seal 306a, 306b to receive a mechanical fastener, such as a rivet <NUM>, to couple the seals 306a, 306b to the at least one skin panel <NUM>.

With reference to <FIG>, the at least one airframe rib <NUM> supports the at least one skin panel <NUM> between the airframe longeron <NUM> and the at least one airframe beam <NUM>. In one example, the at least one airframe rib <NUM> includes two airframe ribs 308a, 308b. In this example, the airframe rib 308a is larger than the airframe rib 308b due to the triangular shape of the vehicle pylon <NUM>. The airframe rib 308a is positioned adjacent to the airframe longeron <NUM> between the cut-outs 324a, 324b, and the airframe rib 308b is positioned adjacent to the airframe longeron <NUM> between the cut-outs 324b, 324c. The airframe ribs 308a, 308b are received between the first airframe flange <NUM> and the second airframe flange <NUM>. In one example, each of the airframe ribs 308a, 308b include a first notch <NUM> and a second notch <NUM>, which are defined on opposite sides of the airframe ribs 308a, 308b to enable the airframe ribs 308a, 308b to be received between the first airframe flange <NUM> and the second airframe flange <NUM>. The first notch <NUM> and the second notch <NUM> are each defined on a first side <NUM> of the airframe ribs 308a, 308b, which is opposite a second side <NUM>. The first side <NUM> is coupled to the airframe longeron <NUM>, and the second side <NUM> is coupled to the at least one airframe beam <NUM>. The second side <NUM> includes L-shaped grooves 408a, 408b (<FIG>). The L-shaped grooves 408a, 408b assist in coupling the at least one airframe beam <NUM> to the airframe ribs 308a, 308b. The airframe ribs 308a, 308b may also include a plurality of rib bores <NUM>, which may be defined along a top side <NUM> and a bottom side <NUM> of the airframe ribs 308a, 308b. The rib bores <NUM> are spaced apart along each of the top side <NUM> and the bottom side <NUM>, and may be threaded to enable a mechanical fastener, such as a rivet <NUM> (<FIG>), to couple the at least one skin panel <NUM> or the at least one airframe beam <NUM> to the airframe ribs 308a, 308b.

In this example, the at least one airframe beam <NUM> includes two airframe beams 310a, 310b. The airframe beams 310a, 310b are composed of a polymer-based material, metal, or metal alloy, and are cast, forged, stamped, additively manufactured, etc. Each of the airframe beams 310a, 310b are L-shaped, and include a skin coupling portion <NUM> and a side portion <NUM>. The skin coupling portion <NUM> is about normal to the side portion <NUM>. The skin coupling portion <NUM> of the airframe beam 310a extends substantially parallel with the first airframe flange <NUM>, and the skin coupling portion <NUM> of the airframe beam 310b extends substantially parallel with the second airframe flange <NUM>. The skin coupling portion <NUM> includes a plurality of holes <NUM> for receiving a mechanical fastener, such as a rivet <NUM> (<FIG>), for coupling the at least one skin panel <NUM> to the airframe beams 310a, 310b. The side portion <NUM> is coupled to the airframe ribs 308a, 308b and provides rigidity to the vehicle pylon <NUM>. Generally, the airframe beams 310a, 310b provide structural strength for attaching the at least one skin panel <NUM> to the vehicle pylon <NUM>.

The at least one skin panel <NUM> encloses a portion of the vehicle pylon <NUM>. In this example, the at least one skin panel <NUM> includes two skin panels 312a, 312b. Each of the skin panels 312a, 312b is composed of a polymer-based material, metal, or metal alloy, and is stamped, machined, cast, additively manufactured, etc. The skin panels 312a, 312b cooperate to enclose the airframe longeron <NUM>, the airframe ribs 308a, 308b and the airframe beams 310a, 310b and to define an exterior surface of the vehicle pylon <NUM>. Each of the skin panels 312a, 312b include a first panel side <NUM> opposite a second panel side <NUM> and a first panel end <NUM> opposite a second panel end <NUM>. The first panel side <NUM> is proximate the engine pylon <NUM>, and includes a cut-out region <NUM>. The cut-out region <NUM> is defined to enable the engine pylon <NUM> to engage and move along the seals 306a, 306b. The second panel side <NUM> is coupled to the aircraft <NUM> (<FIG>) and a portion of the second panel side <NUM> is coupled to the airframe beams 310a, 310b. The first panel end <NUM> of each of the skin panels 312a, 312b are coupled together to enclose the first panel end <NUM> (<FIG>). The second panel end <NUM> of each of the skin panels 312a, 312b are coupled together to enclose the second panel end <NUM> (<FIG>). Generally, the skin panels 312a, 312b are slightly different in exterior shape to provide the predetermined optimal shape for the vehicle pylon <NUM> based on the aerodynamics associated with the aircraft <NUM>.

Each of the skin panels 312a, 312b also include a plurality of panel bores <NUM>. A portion of the panel bores <NUM> are defined through the skin panel 312a proximate the first panel side <NUM> to couple the skin panel 312a to the skin panel 312b, the airframe longeron <NUM>, the seal 306a, the seal fastening assembly 304a and the airframe ribs 308a, 308b. A portion of the panel bores <NUM> are defined through the skin panel 312b proximate the first panel side <NUM> to couple the skin panel 312b to the skin panel 312a, the airframe longeron <NUM>, the seal 306b, the seal fastening assembly 304b and the airframe ribs 308a, 308b. In one example, with reference to <FIG>, the rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312a, the first airframe flange <NUM> and is secured with the airframe nut plates <NUM>. The rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312a, the seal bore <NUM>, the hole <NUM> of the seal fastening assembly 304a and is secured with the respective seal nut plates <NUM>. The rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312b, the second airframe flange <NUM> and is secured with the airframe nut plates <NUM>. The rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312b, the seal bore <NUM>, the hole <NUM> of the seal fastening assembly 304b and is secured with the respective seal nut plates <NUM>. A portion of the panel bores <NUM> are defined through the skin panel 312a proximate the second panel side <NUM> to couple the skin panel 312a to the airframe ribs 308a, 308b and the airframe beams 310a, 310b. A portion of the panel bores <NUM> are defined through the skin panel 312b proximate the second panel side <NUM> to couple the skin panel 312b to the airframe ribs 308a, 308b and the airframe beams 310a, 310b. A portion of the panel bores <NUM> are defined to extend between the first panel side <NUM> and the second panel side <NUM> and are coaxially aligned with a respective one of the rib bores <NUM> to couple the skin panel 312a, 312b to the airframe ribs 308a, 308b with a respective one of the rivets <NUM> (<FIG>).

In addition, the skin panel 312b defines an airframe access opening <NUM>, which is enclosed with a removable airframe access panel <NUM>. With reference to <FIG>, the airframe access opening <NUM> is defined so as to be proximate the cut-out 324a of the airframe longeron <NUM> to provide access to the fastening aperture 154a, 154b (<FIG>) to enable adjustment of the coupling between the engine pylon <NUM> and the transcowl <NUM> during installation and use. The airframe access opening <NUM> is generally sized to enable an operator to insert their hand and manipulate the fastening device coupled to the fastening aperture 154a, 154b, such as the locking positioning system <NUM>, previously incorporated by reference herein. The airframe access panel <NUM> is composed of a polymer-based material, metal, or metal alloy, and is stamped, machined, cast, additively manufactured, etc. The airframe access panel <NUM> is coupled to the airframe access opening <NUM> via press-fit, mechanical fasteners, etc. Generally, the airframe access panel <NUM> is coupled to the airframe access opening <NUM> to be removable for maintenance, but secured during operation of the aircraft <NUM> (<FIG>). It should be noted that the vehicle pylon <NUM> may include a number of other components, including, but not limited to, additional aircraft beams, fasteners, seals, pre-coolers, control valves, thrust links, etc. depending upon the aircraft <NUM>, which are outside of the scope of the present disclosure.

With brief reference back to <FIG>, in one example, in order to assemble the engine pylon <NUM>, the spacers 140a, 140b are positioned on the respective one of the first flange <NUM> and the second flange <NUM>. The elongated seals 136a, 136b are positioned adjacent to the respective one of the first flange <NUM> and the second flange <NUM> to be opposite the respective one of the spacers 140a, 140b. The fastening assemblies 138a, 138b are positioned on the fastening strips <NUM> of the respective elongated seals 136a, 136b. With the nut plates <NUM> and the second nut plates <NUM> coupled to the outboard longeron <NUM>, the outboard longeron <NUM> is positioned over the inboard longeron <NUM> such that the projection <NUM> and the second projection <NUM> overlie the first flange <NUM> and the second flange <NUM>, respectively, and are positioned adjacent to the spacers 140a, 140b. The forward seal <NUM> is coupled to the inboard longeron <NUM>. The first base <NUM> of the inboard longeron <NUM> is coupled to the second base <NUM> of the outboard longeron <NUM>. Generally, the inboard longeron <NUM> is coupled to the outboard longeron <NUM> at a first end 120a of the engine pylon <NUM> and is spaced apart from the outboard longeron <NUM> at a second end 120b of the engine pylon <NUM>. The skin panel <NUM> is positioned about the inboard longeron <NUM> and the outboard longeron <NUM>. The rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the first skin panel surface <NUM>, the coupling holes <NUM> of the spacer 140a, the seal holes <NUM> of the elongated seal 136a, the holes <NUM> of the fastening assembly 138a and are secured to the respective one of the nut plates <NUM>. The rivets <NUM> are inserted through respective ones of the skin panel bores <NUM> of the second skin panel surface <NUM>, the coupling holes <NUM> of the spacer 140b, the seal holes <NUM> of the elongated seal 136b, the holes <NUM> of the fastening assembly 138b and are secured to the respective one of the nut plates <NUM>.

With reference to <FIG>, with the engine pylon <NUM> assembled, the engine pylon <NUM> is coupled to the transcowl <NUM>. In one example, the locking positioning system <NUM>, previously incorporated by reference herein, is coupled to the transcowl <NUM> and the inboard longeron <NUM> to couple the engine pylon <NUM> to the gas turbine engine <NUM>. Each of the locking positioning systems <NUM> may be adjusted along the slot serrations <NUM> defined by the fastening apertures 154a-154c to adjust a position of the gas turbine engine <NUM> along a Z-axis, in a rectangular coordinate system in which the X-axis is parallel to a center axis C of the gas turbine engine <NUM>. Stated another way, the slot serrations <NUM> enable the locking positioning system <NUM> to secure the engine pylon <NUM> at various positions on the exterior of the transcowl <NUM>. Once the engine pylon <NUM> is coupled to the gas turbine engine <NUM>, the engine pylon <NUM> is coupled to the vehicle pylon <NUM>.

With brief reference back to <FIG>, in one example, in order to assemble the vehicle pylon <NUM>, the airframe forward seal <NUM> is coupled to the seal bracket <NUM>. The airframe ribs 308a, 308b are coupled to the first airframe flange <NUM> and the second airframe flange <NUM>. The airframe beams 310a, 310b are coupled to the airframe ribs 308a, 308b. The seals 306a, 306b are positioned on the respective one of the first airframe flange <NUM> and the second airframe flange <NUM>. The seal fastening assemblies 304a, 304b are positioned next to the respective one of the seals 306a, 306b. The skin panel 312b is coupled to the seal 306b, the airframe longeron <NUM>, the airframe ribs 308a, 308b and the airframe beam 310b. The rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312b, the seal bore <NUM>, the hole <NUM> of the seal fastening assembly 304b and is secured with the respective seal nut plate <NUM>. The rivets <NUM> are each inserted through the panel bores <NUM> and the respective rib bores <NUM> to couple the airframe ribs 308a, 308b to the skin panel 312b. Fasteners, such as rivets, are each inserted through the panel bores <NUM> to couple the airframe ribs 308a, 308b to the airframe beam 310b. The skin panel 312a is coupled to the seal 306a, the airframe longeron <NUM>, the airframe ribs 308a, 308b and the airframe beam 310a. The rivet <NUM> is inserted through the panel bore <NUM> of the skin panel 312a, the seal bore <NUM>, the hole <NUM> of the seal fastening assembly 304a and is secured with the respective seal nut plate <NUM>. The rivets <NUM> are each inserted through the panel bores <NUM> and the respective rib bores <NUM> to couple the airframe ribs 308a, 308b to the skin panel 312a. Fasteners, such as rivets, are each inserted through the panel bores <NUM> to couple the airframe ribs 308a, 308b to the airframe beam 310a. With the vehicle pylon <NUM> assembled, the vehicle pylon <NUM> is coupled to the airframe <NUM> of the aircraft <NUM> (<FIG>). In one example, the vehicle pylon <NUM> is coupled to a beam of the airframe <NUM> to enable fuel, pneumatic, hydraulic, and electric energy to transfer from the gas turbine engine <NUM> to the aircraft <NUM>.

With reference to <FIG>, with the vehicle pylon <NUM> coupled to the aircraft <NUM>, the engine pylon <NUM> is coupled to the vehicle pylon <NUM> to couple the gas turbine engine <NUM> to the aircraft <NUM>. It should be noted that the gas turbine engine <NUM> may also be coupled to the airframe <NUM> of the aircraft <NUM> at additional locations, if desired. In one example, the first rail 239a and the second rail 239b defined by the respective portion of the first skin panel surface <NUM> and the second skin panel surface <NUM> that overhangs the outboard longeron <NUM> is positioned over the respective blade seal <NUM> of the vehicle pylon <NUM>. Generally, a gap is defined between the first skin panel surface <NUM> and the skin panel 312a, and the second skin panel surface <NUM> and the skin panel 312b. The gap is about <NUM> (<NUM>,<NUM> inches) plus or minus about <NUM> (<NUM> inches). The first rail 239a and the second rail 239b are movable or slidable along the blade seal <NUM> until the transcowl <NUM> is in the first, stowed position of <FIG> and the engine pylon <NUM> is in the first position. Generally, the engine pylon <NUM> is coupled to the vehicle pylon <NUM> such that the skin panel 312a, 312b is substantially parallel with the first skin panel surface <NUM> and the second skin panel surface <NUM>, respectively, and substantially parallel to the centerline C of the gas turbine engine <NUM> (<FIG>) to reduce or substantially eliminate drag. In the first, stowed position, with reference to <FIG>, the forward seal <NUM> of the engine pylon <NUM> is adjacent to and in contact with the airframe forward seal <NUM>. The airframe access panel <NUM> enables an operator to adjust the coupling of the gas turbine engine <NUM> relative to the aircraft <NUM> once installed to ensure a proper alignment between the engine pylon <NUM> and the vehicle pylon <NUM> (<FIG>). In addition, the access panel <NUM> of the engine pylon <NUM> enables further adjustment of the engine pylon <NUM> relative to the gas turbine engine <NUM> to further ensure that the gas turbine engine <NUM> is properly aligned with the aircraft <NUM> (<FIG>), which also reduces drag.

During operation of the gas turbine engine <NUM>, with reference to <FIG>, the transcowl <NUM> may be moved, via signals to the actuator received from the controller associated with the gas turbine engine <NUM>, to the third, overstowed position. In the third, overstowed position, the transcowl <NUM> is moved forward to unload locks associated with the transcowl <NUM> to enable the transcowl <NUM> to move to the second, deployed position. The advancement of the transcowl <NUM> relative to the gas turbine engine <NUM> causes the first rail 239a and the second rail 239b to move or slide along the blade seal <NUM> of the respective seals 306a, 306b until the engine pylon <NUM> is in the third position and the transcowl <NUM> is in the third, overstowed position. In the third position, the forward seal <NUM> of the engine pylon <NUM> compresses the airframe forward seal <NUM> to form a tight seal between the gas turbine engine <NUM> and the aircraft <NUM>. In addition, during operation of the gas turbine engine <NUM>, with reference to <FIG>, the transcowl <NUM> may be moved, via signals to the actuator received from the controller associated with the gas turbine engine <NUM>, to a second, deployed position. In the second, deployed position, the transcowl <NUM> is moved aft relative to the gas turbine engine <NUM> to define the aperture <NUM>. With reference to <FIG>, the aft movement of the transcowl <NUM> relative to the gas turbine engine <NUM> causes the first rail 239a and the second rail 239b to move or slide along the blade seal <NUM> of the respective seals 306a, 306b until the engine pylon <NUM> is in the second position and the transcowl <NUM> is in the second, deployed position. In the second, deployed position, the forward seal <NUM> of the engine pylon <NUM> is spaced a distance apart from the airframe forward seal <NUM>.

Thus, with reference to <FIG>, the pylon system <NUM> enables the gas turbine engine <NUM> to be mounted to a side of the aircraft <NUM> with the thrust reverser <NUM>. By providing the engine pylon <NUM> movable relative to the vehicle pylon <NUM> between the first position, the second position and the third position, the transcowl <NUM> is also movable between the first, stowed position, the second, deployed position and the third, overstowed position, respectively, without interfering with the side or rear mounting of the gas turbine engine <NUM> to the aircraft <NUM>. The ability to employ the transcowl <NUM> with the gas turbine engine <NUM> improves the stopping performance of the aircraft <NUM>, which may be desirable in certain landing conditions. Moreover, by providing the inboard longeron <NUM> with the fastening apertures <NUM> (<FIG>) that may be used with the locking positioning system <NUM>, the position of the engine pylon <NUM> relative to the transcowl <NUM> is adjustable in multiple degrees of freedom, such as about <NUM> degrees of freedom, which enables the engine pylon <NUM> and the gas turbine engine <NUM> to be positioned at a position relative to the aircraft <NUM> that reduces or substantially eliminates drag. In addition, the elongated seals 136a, 136b, the forward seal <NUM>, the airframe forward seal <NUM> and the seals 306a, 306b reduce leakage around the components of the pylon system <NUM>.

Claim 1:
A pylon system for coupling an engine to a vehicle, comprising:
a vehicle pylon (<NUM>) configured to be coupled to the vehicle, the vehicle pylon including a seal (<NUM>) along a portion of the vehicle pylon; and
an engine pylon (<NUM>) including an inboard longeron (<NUM>) and an outboard longeron (<NUM>), the inboard longeron coupled to the outboard longeron at a first end of the engine pylon and spaced apart from the outboard longeron at a second end of the engine pylon, the inboard longeron configured to be coupled to the engine, and the engine pylon is slidably coupled to the seal such that the engine pylon is movable relative to the vehicle pylon between at least a first position and a second position.