Abstract:
A method, system, and apparatus for attaching a fairing to a body or aircraft wing are disclosed. A plurality of attach anchors is disposed on the body or aircraft wing to which the fairing is to be attached. Disposed in the fairing is a plurality of core pockets that are alignable with the plurality of attach anchors, and each of the core pockets defines a channel. The fairing is placed over the body or the aircraft wing such that the heads of the attach anchors are received in the core pockets. The fairing is then slid across the body or the aircraft wing with the channels sliding along the heads of the attach anchors such that the fairing is prevented from being lifted away from the body or aircraft wing.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to structural attachment and, more specifically, to structural attachment of fairings. 
     BACKGROUND OF THE INVENTION 
     Ongoing research into aircraft design from time to time may discover improved wing contour designs to improve aircraft performance. Even subtle changes in wing contours may, for example, improve lift-to-drag ratios. Such improvements in lift-to-drag ratios can result in greater aircraft lift capacity or improved fuel economy per unit cargo weight. Certainly, future aircraft can benefit greatly from these enhancements. 
     Although future aircraft will benefit from such improvements, it would be advantageous to be able to incorporate these design changes in aircraft currently in service. Currently used aircraft have useful lives measured in decades, and such durable assets certainly represent an appreciable investment which owners would like to be able to upgrade. Accordingly, it would be advantageous to incorporate improved wing designs in currently deployed commercial or military aircraft. 
     Unfortunately, changing wing contours on currently in-service aircraft presents a considerable challenge. Wings on aircraft must be intricately interconnected with their aircraft to allow for flight deck controls to be connected to the many control surfaces that constitute part of the wings. Moreover, other aircraft systems, such as fuel tanks, are integrated into the wings. As a result, it is not very feasible to remove an aircraft wing and replace it with a new and improved wing. On the other hand, wing contours of existing aircraft can be modified in place by applying fairings to a surface of the wing. In particular, a contour of an upper wing surface can be changed by affixing a convex fairing to the upper wing surface. 
     Problems remain, however, in how to accomplish the attachment of fairings to such wing surfaces practicably, cost effectively, and durably. For example, mounting a fairing to a hollow aircraft wing housing a fuel tank presents all of the above problems. The fairing would have to be anchored to structural members within the wing such as stringers to be durable. At the same time, the fairing has to be attached without puncturing the fuel tanks inside the wing. Drilling or otherwise driving an attachment device through the fairing and into the wing, engaging the stringers, and not puncturing the tank presents a formidable problem. The problem becomes especially daunting if it is to be accomplished cost effectively within a reasonable amount of time and without incurring wasted expenses for repairing damaged wing supports or resealing punctured fuel tanks. 
     Thus, there is an unmet need in the art for attaching a fairing to an aircraft wing with a method that is durable, cost effective, and practicable to allow in-service aircraft to benefit from improvements in wing contour design. 
     SUMMARY OF THE INVENTION 
     The present invention provides a practical method for attaching a fairing to a body. The method allows for attach anchors to be inserted into the wing directly, optionally using existing securing orifices used to secure a body surface to the supporting structure of the body. Using existing securing orifices allows the attach anchors to be installed without meticulously drilling of the fairing and the surface of the body in order to connect with a structural member while not puncturing a tank. The fairing can then be mounted over the attach anchors, slid into place, and locked in position, achieving a practical and durable connection of the fairing to the wing. 
     An exemplary embodiment of the present invention provides a method for attaching a fairing to a body or aircraft wing. A plurality of attach anchors is disposed on the body or aircraft wing to which the fairing is to be attached. Disposed in the fairing is a plurality of core pockets that are alignable with the plurality of attach anchors, and each of the core pockets defines a channel. The fairing is placed over the body or the aircraft wing such that heads of the attach anchors are received in the core pockets. The fairing is then slid across the body or the aircraft wing with the channels sliding along the heads of the attach anchors such that the fairing is prevented from being lifted away from the body or aircraft wing. 
     Embodiments of the present invention may employ attach anchors shaped to match an inner cross-sectional shape of the channels of the core pockets in the fairing. An attach anchor may be a one piece assembly. Alternatively, an attach anchor may include an interlocking fitting at the head of the attach anchor, where the interlocking fitting is shaped to engage the channel. The interlocking fitting then is secured to the body wing surface with a securing pin mounted through the interlocking fitting. The interlocking fitting may be engaged by the securing pin through a bushing having an eccentric opening, thereby allowing the interlocking fitting to be aligned to match positions of the core pockets in the fairing. The attach anchors may include securing orifices so that locking members can be inserted through the fairing into the securing orifices once the fairing is in place to lock the fairing in position. As desired, a transitioning member can be applied over such a fairing to seal any gaps around the fairing. Embodiments may be used with any bodies that can benefit from a changed shape, including aircraft wings, aircraft bodies, or other shapes as desired for a particular application. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. 
     FIG. 1 is a cross-sectional view of an aircraft wing with a fairing; 
     FIG. 2A is a top view of an aircraft wing with a plurality of fairing panels; 
     FIG. 2B is an enlarged view of a plurality of the fairing panels of FIG. 2A; 
     FIG. 3A is a cross-sectional view across a channel of one of the fairing panels; 
     FIG. 3B is another cross-sectional view from a perspective rotated ninety degrees from that of FIG. 3A along the channel of one of the fairing panels prior to engagement of the fairing panel; 
     FIG. 3C is another cross-sectional view along the channel of one of the fairing panels with the fairing secured in place; 
     FIG. 4 is a cross sectional view of a fairing panel mounted on a wing surface and fitting with a transitioning member; and 
     FIG. 5 is a flowchart of a method of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a cross-sectional view of an aircraft wing  100  with a fairing  110  attached to the wing  100 . The wing  100  has a lower surface  120  and an upper surface  130  to which the fairing  110  is attached. As can be appreciated from FIG. 1, the attachment of the fairing  110  changes a contour of the wing  100  from that which was defined at the upper surface  130  of the wing by the original contour of the wing  100  to the contour now incorporating the fairing  110 . Embodiments of the present invention permit such attachment in a practical manner. It will be appreciated that applicability of embodiments of the present invention is not limited to aircraft wings. For one nonlimiting example, with aeronautic lifting body designs, a fairing might suitably be attached to a main body of an aircraft. For another nonlimiting example, a fairing might suitably be attached to a hull of a marine vessel to adjust fluid dynamic properties of water passing across the hull. 
     FIG. 2A shows a top view of an aircraft wing  200  with a plurality of fairing panels  210  mounted thereon using an exemplary embodiment of the present invention. As will be further described, the fairing panels  210  each are mounted to a plurality of attach anchors  220  installed on the surface  230  of the wing  200 . As also will be further explained, the attach anchors  220  are directly mounted onto the surface  230  of the wing  200  and the fairing panels  210  are then attached to the attach anchors  220 . FIG. 2A shows that the fairing panels  210  can be applied to parts of the surface  230  of the wing  200  both near a fuselage  240  of an aircraft and away from the fuselage  240 . FIG. 2A also shows how a long fairing panel  250  can be applied completely across a length of the surface  230  of the wing  200 . FIG. 2A also shows how a short fairing panel  260  may be applied across only a part of a length of the surface  230  of the wing  200 . Wing contour improvements and an original wing contour appropriately dictate a shape, size, and contour of the fairing panels  210 . The circled area  270  is enlarged in FIG. 2B to better show how the fairing panels  210  are joined to the surface  230  of the wing  200 . 
     FIG. 2B shows in more detail how the fairing panels  210  are secured to the wing surface  230  in one presently preferred embodiment. FIG. 2B shows that the attach anchors  220  are received in core pockets  280  in the fairing panels  210 . FIG. 2B shows one presently preferred embodiment of the invention in which the core pockets  280  incorporate an angled channel  290 . The angled channel  290  is disposed approximately perpendicular to a direction  295  in which the aircraft will travel. The sides of the angled channel  290  describe a width which narrows toward an underside (not shown) of the fairing panels  210  to securely engage the attach anchors  220 , which will be shown in more detail in FIG.  3 A. The fairing panels  210  are installed by positioning the core pockets  280  over the attach anchors and sliding the fairing panels  210  toward the fuselage  240  to secure the fairing panels in place. In such a presently preferred embodiment, forces on the fairing panels  210  caused by airflow over the wing surface  230  from travel are approximately perpendicular to the angled channel  290  of the core pockets  280 . Thus, forces caused by the airflow on the fairing panels  210  advantageously do not strain the attach anchors  220  or the core pockets  280  along the direction in which the fairing panels are slidably installed on the wing surface  230 . It will also be appreciated from FIG. 2B that the fairing panels  210  can be shaped in a number of ways to effect a new wing contour across the wing surface  230 . For example, the fairing panels  210  include a fairing a long fairing panel  250 , a short fairing panel  260 , and an angled fairing panel  298 . Embodiments of the present invention do not restrict the shape of the fairing panels  210  that can be used. 
     FIGS. 3A,  3 B, and  3 C show in more detail how the attach anchors  220  engage the core pockets  280  to attach a fairing panel  210  to a wing surface  230 . FIG. 3A shows an enlarged cross-sectional view of the fairing panel  210  looking across the angled channel  290  of one of the core pockets  280  of a fairing panel  210 . More specifically, FIG. 3A shows the attach anchor  220  engaging the angled channel  290  of one of the core pockets  280  in an installed position. 
     In one presently preferred embodiment, the fairing panel  210  itself is suitably a composite, honeycomb-stiffened panel having pockets of a solid material around attachment points  300  such as that shown in FIG.  3 A. Such a panel is advantageously lighter in weight than a panel made entirely of a solid material of sufficient sturdiness to withstand forces applied to the fairing panel  210  about such an attachment point. The angled channel  290  is fitted within the core pocket  280 . As previously described in connection with FIG. 2B, the angled sides narrow toward an underside  310  of the fairing panel  210  with the underside  310  of the fairing panel  210  facing the wing surface  230 . Inward-facing sides of the angled channel  290  thereby securely engage outward-facing sides of the attach anchor  220 . 
     More specifically, in the embodiment shown in FIG. 3A, the attach anchor  220  has four parts: an interlocking fitting  315 , a cylindrical fastener  320 , a bushing  330 , and a self-sealing collar  340 . In one presently preferred embodiment, the interlocking fitting  315  is shaped to substantially match an inner cross-section of the angled channel  290  to effect a secure fit between the attach anchor  220  and the core pocket  280 . The interlocking fitting  315  receives the bushing  330  which, in turn, receives the cylindrical fastener  320 . The interlocking fitting  315  suitably is formed to receive an off-the-shelf bushing  330 , and the bushing  330  may include an eccentric or slotted opening through which the fastener  320  is received or have an undersized outside diameter relative to an opening in the interlocking fitting  315  the bushing  330  will engage. The eccentric, slotted, or undersized diameter opening in the bushing  330  allows the interlocking fitting  315  to be adjusted in position to align with a respective core pocket  280  in the fairing, and then to be substantially secured to the surface with the fastener  320 . 
     In one presently preferred embodiment, the interlocking fittings  315  would be aligned by creating a template of positions of the core pockets  280  in a respective fairing panel  210 . The template is placed over the body or wing surface to which the fairing panel  210  will be mounted, and provide a guide through which the attach anchors  220  are installed and aligned to receive the core pockets  280 . Once aligned, the fasteners  320  can be tightened to their fully installed position and thereby secure the interlocking fittings  315  in place to ultimately securely hold the fairing panel  210  in place. 
     The fastener  320 , once installed through the bushing  320  and the interlocking fitting  315  is capped with the self-sealing collar  340 . The fastener  320  in one presently preferred embodiment is received in an existing fastener orifice  350  in the wing surface  230 , thereby replacing an ordinary fastener used to secure a wing surface material  360  to a stringer  370  or other structural member that supports the wing surface  230 . The self-sealing collar  340  disposed on a wing-facing, inside end  380  of the fastener  320 . Once installed, the collar  340  seals against the stringer  370 . Accordingly, if the attach anchor  220  is installed through a portion of the wing surface  230  that includes a fuel or other tank, inserting the attach anchor  220  advantageously does not create an opening in the tank. It will also be appreciated that, when a stringer  370  extends through such a tank, the stringer  370  may be fillet-sealed (not shown) to guard against leakage between the stringer  370  and the wing surface material  360 , then along the shank of the fastener  320  to the wing surface  230 . 
     At an opposite end of the fastener  320  from the inside end  380 , an outside, broadened head  390  of the fastener  320  engages the bushing  330  to hold the bushing  330  and, thus, the interlocking fitting  315  in place. In the embodiment shown, the angled channel  290  of the core pocket  280  engages the interlocking fitting  315 , which in turn is secured to the wing surface  230  by the fastener  320 . 
     From FIG. 3A, other aspects of the embodiment of the invention shown will be appreciated. First, it will be appreciated that the attach anchor  220  may be formed in other ways. For one example, the interlocking fitting  315  could be shaped to directly receive the fastener  220  without using a bushing  330 . Second, it will be appreciated that the angled channel  290  is suitably formed into the material of the fairing panel  210 . Alternatively, the angled channel  290  is suitably composed of a separately formed material that is bonded or otherwise fastened to the fairing panel  210 . Also, it will be appreciated that the interlocking fitting  315  or other head of the attach anchor  220  in one presently preferred embodiment closely fits sides of the angled channel  290 . This provides a secure coupling of the fairing panel to the wing surface  230 . At the same time, however, sufficient clearance between the interlocking fitting  315  other head of the attach anchor  220  and the inward-facing sides of the angled channel is desired so that the attach anchor  220  and the angled channel  290  do not become jig-locked while the fairing panel  210  is being installed on the wing surface  230 . Also, it will be appreciated that the attach anchors  220  suitably have a round head or a rectangular head as desired, as long as the head shape chosen fits the shape of the angled channel  290  with which the attach anchor will engage. 
     FIG. 3B is a cross-sectional view of the attach anchor  220  and the angled channel  290  from a ninety-degree perpendicular angle to that shown in FIG. 3A in which the attach anchor  220  has not yet been received into the angled channel  290 . Therefore, FIG. 3B shows how the fairing panel  210  can be applied to the wing surface  230  so that the fairing panel  210  can be fastened to the wing surface  230  using the attach anchor  220  and the core pocket  280 . 
     As previously mentioned, in one presently preferred embodiment of the invention installation involves sliding the fairing panel  210  across the wing surface  230  to permit the fairing panel  210  to engage the attach anchors  220  with the angled channel  290 . In such an embodiment, the core pockets  280  include a receiving aperture  394  which can receive the interlocking fitting  315  or other head of the attach anchor  220  from a direction perpendicular to the wing surface  230  and the angled channel  290 . As will be appreciated with comparison to FIG. 3A, once the attach anchor  220  is received in the angled channel  290 , the angled channel  290  holds the fairing panel  210  in place on the wing surface  230 . This prevents the fairing panel  210  from being lifted away from the wing surface  230 . However, to apply the fairing panel  210  to the wing surface  230  before it is secured, the fairing panel  210  incorporates the receiving aperture  394  to receive the attach anchor  220 . 
     The receiving aperture  394  of the core pocket  280  is suitably an enlarged opening in the angled channel  290  itself. Alternatively, as shown in FIG. 3B, the receiving aperture  394  represents a space past an end of the angled channel  290 . Taking advantage of the receiving aperture  394 , the fairing panel  210  can be placed with the receiving apertures  394  of its core pockets  280  over the attach anchors  220  and pressed against the wing surface  230 . Then, the fairing panel can be slid into place as shown to secure the fairing panel  210  to the wing surface  230 . 
     Once the fairing panel  210  is anchored to the wing surface  230  as shown in FIGS. 3A and 3C, the fairing panel  210  can be locked into place so that the fairing panel  210  cannot be disengaged from the wing surface by sliding it in an opposite direction. FIG. 3C shows the attach anchor  220  and the angled channel  290  from the same perspective as FIG. 3B, but this time showing the attach anchor  220  received in the angled channel  290 . Once received in the angled channel  290 , the fairing panel  210  can be locked into place by a locking fastener  396 . The locking fastener  396  passes through a solid area  397  of the fairing panel  210 . In one presently preferred embodiment of the invention, the locking fastener  396  is received by a locking orifice  398  in the interlocking fitting  315  or other head of the attach anchor  220 . Alternatively, the locking fastener  396  is suitably received in an orifice in the wing surface  230 . For example, the attach anchor  220  is suitably received in an orifice  350  in the embodiment shown. The locking fastener  396  suitably is one of a screw, setscrew, bolt, rivet, stop fastener, or other similar fastener. Once the locking fastener  396  engages the locking orifice  398 , advantageously the fairing panel  210  cannot be slid back over the wing surface  230  in a direction from which it was installed to remove it from the wing surface  230 . 
     FIG. 4 shows a cross-sectional view of a portion of a wing  400  equipped with a fairing panel  210  which is fitted with a transitioning member  410 . The transitioning member  410  smoothes an edge  420  of the fairing panel to the wing surface  430 . Without the transitioning member  410  in place, a blunt edge would exist at the edge  420  of the fairing panel  210  which would create drag. Also, the transitioning member  410  acts to prevent fluids, such as water or air, from entering under the fairing panel  210 . 
     More specifically, FIG. 4 shows how the transitioning member  410  is joined to the fairing panel  210  and wing surface  430 . The transitioning member  410  extends from the edge  420  of the fairing panel  210  where it is joined to the fairing panel  210  with a transitioning member fastener  440 . The fastener  440  suitably is a screw, rivet, or other attachment device to forcibly join the transitioning member  410  to the fairing panel  210 . More specifically, the fastener  440  engages the transitioning member by passing through a fairing panel surface  450  and into the transitioning member  410 . As shown, the fairing panel has a square edged core with fairing panel surface  450  having a cantilevered extended junction which engages the transitioning member  410 . At an end of the transitioning member  410  opposite the fairing panel  210 , the transitioning member  410  tapers to become flush with the wing surface  430  where it can be joined to the wing surface  430  with suitable adhesive. In one presently preferred embodiment, the transitioning member  410  is an extruded part composed of a flexible material. Flexibility of the material facilitates installation and allows the transitioning member  410  to be resilient to damage if weight is placed on the transitioning member  410  or its surface incurs some sort of impact. The transitioning member  410  shown is extruded to incorporate hollow cavities  460  which also allow the transitioning member  410  to have a reduced mass so as not to add unnecessary weight to the wing  400  to which it is mounted. It will be appreciated that the transitioning member  410  can be composed of an inexpensive material such that, if the transitioning member  410  and/or the fairing panel  210  had to be removed from the wing surface, it could be inexpensively replaced with a new one. 
     FIG. 5 is a flowchart of an exemplary method  500  of attaching fairing panels to a body, such as, without limitation, a wing surface  230  (FIGS.  2 A and  2 B). At a block  510 , the attach anchors are installed on the wing or body to which the fairing is to be mounted. At a block  520 , the fairing panel is fabricated with core pockets are formed to accommodate and engage the attach anchors. It will be appreciated that the order of these steps could be made in another order as desired for a particular application. At a block  530 , the fairing panel is positioned with the core pockets over the attach anchors to receive the attach anchors within the body of the fairing panel. Once in place, at a block  540  the fairing panel is slid across the surface of the body or the wing so that the attach anchors engage the core pockets to prevent the fairing from being lifted away from the body or wing. At a block  550 , the fairing panel is locked in place to prevent the fairing panel from being slid back off the attach anchors. At a block  560 , a transitioning member is applied adjacent the fairing panel to seal gaps around the fairing panel, or between the fairing panel and any other fairing panels. This method can be repeated for as many fairing panels as desired to be installed on the body or wing. 
     While the preferred embodiment of the invention has been illustrated and described in the context of attaching a fairing to an aircraft wing, embodiments of the present invention could be used to attach fairings to other bodies that could benefit from enhanced aerodynamic, fluid dynamic, or other properties that could be improved by the addition of one or more fairings. In addition, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.