CROSS-REFERENCE TO RELATED APPLICATIONS 0001 This application claims, and is entitled to, the benefit of Provisional Patent Application Serial No. 60/182,252, filed Feb. 14, 2000, the specification of which is hereby incorporated by reference into the present application.

FEDERAL RESEARCH 0002 Not applicable.

BACKGROUND-FIELD OF INVENTION 0003 The present invention pertains to an aircraft wing or lifting airfoil that incorporates trailing edge flaps and ailerons as primary flight control surfaces; and improves the performance of said airfoil. 0004 More particularly, this invention addresses the geometry and camber of the airfoil profile and improves the overall aerodynamic efficiency of the airfoil during its operation by means of relocating the trailing edge devices to predetermined positions. 0005 In general, an airfoil is designed for a particular aircraft and the specific use of that aircraft. In most instances the lift and drag characteristics of any given airfoil can be further optimized using established aerodynamic principles.

BACKGROUND-DESCRIPTION OF PRIOR ART 0006 It is well known and extensively documented that changes in an airfoil's camber during various phases of flight produce optimal results. It has also been suggested that changing the shape of an airfoil's trailing edge, or attaching certain devices to it, will effectively alter the camber and increase airfoil efficiency. 0007 An object of the present invention is to provide a new fixed camber, employed by the airfoil for the majority of the time that it is in operation, resulting in a greater lift-to-drag ratio and reduced fuel consumption for normal flight operations. 0008 Accordingly, prior art describes and depicts various devices intended to change the camber of an airfoil in flight. Typical of such devices are those shown in the following patents: 0009 U.S. Pat. No. 4,131,253, Zapel 0010 U.S. Pat. No. 4,725,026, Krafka et al. 0011 U.S. Pat. No. 4,741,503, Anderson et al. 0012 U.S. Pat. No. 4,899,284, Lewis et al. 0013 U.S. Pat. No. 5,740,991, Gleine et al. 0014 U.S. Pat. No. 5,875,998, Gleine et al. 0015 U.S. Pat. No. 6,010,098, Campanile et al. 0016 U.S. Pat. No. 6,045,096, Rinn et al. 0017 U.S. Pat. No. 6,076,775, Bauer 0018 U.S. Pat. No. 4,444,368, Andrews, narrows the re-cambering of the wing to a variable displacement of the aft flap. 0019 U.S. Pat. No. 4,053,124, Cole, changes wing camber utilizing the leading and/or trailing edge devices and a flexible skin panel. 0020 Wing camber changes are necessary and desirable during certain low speed aspects of flight, i.e., Take Off, Approach, Landing; and therefore leading edge devices and trailing edge flaps have been incorporated into the systems and operations of aircraft for decades. 0021 To date the concept of changing an airfoil's camber during flight solely to produce optimal efficiency has yet to be put to practical use. Lack of practical mechanical designs, reliability, and functional hardware; restricts the use of these devices for aerodynamic, structural, and economic considerations. 0022 An object of the present invention is to utilize all trailing edge devices of an airfoil to obtain maximum efficiency throughout the majority of the flight regime. 0023 U.S. Pat. No. 4,867,396, Wainfan, installs a small fixed flap like device to the trailing edge of an airfoil without consideration of trailing edge flaps; or if trailing edge flaps are a part of the airfoil, without consideration of this device's effects upon the airfoil with trailing edge flaps deployed. 0024 U.S. Pat. No. 5,265,830, Allen, installs a plate across the span of the trailing edge of an airfoil, and is only applicable to an airfoil having a blunt trailing edge. 0025 U.S. Pat. No. 4,542,868, Boyd, attaches a wedge shaped flap at or near the trailing edge of an airfoil to improve the coefficient of lift and reduce the coefficient of drag. This effectively creates an airfoil having a blunt trailing edge with an increase in pressure drag at all but certain optimal airspeeds. 0026 U.S. Pat. No. 5,088,665, Vijgen, Howard, Bushnell, Holmes, incorporates the attachment of a serrated panel to a lifting surface. While in theory this apparatus may improve lift or drag characteristics of an airfoil, the authors have made no claims regarding fuel efficiency in an aircraft. 0027 An object of the present invention is to increase the coefficient of lift and decrease the coefficient of drag with out attaching any external devices to the trailing edge of the airfoil. 0028 U.S. Pat. No. 5,555,651, Henderson, describes a new configuration of a trailing edge flap for a wing which is effective during trailing edge flap extension only. 0029 U.S. Pat. No. 5,342,004, Bobbitt, redesigns the surface contours of the final flap segment to enhance the performance of the airfoil. Altering surface contours may have undesirable aerodynamic effects and loads on aircraft mechanisms controlling the flap segments. 0030 Replacement of conventional flight control surfaces with re-contoured flight control surfaces has not been accepted or proven in the aerospace community. 0031 An object of the present invention is to change the camber of an airfoil without changing the shape or contour of any component of the airfoil. 0032 U.S. Pat. No. 5,407,153, Kirk et al., mounts winglets on an existing Boeing 727 type airplane and re-rigs some of the wing trailing edge flight control surfaces in order to redistribute wing bending and shear loads and contribute to fuel mileage. In this instance the addition of winglets to the airfoil is the major contributing factor to the airfoil's improved performance. 0033 In 1996 a Supplemental Type Certificate was issued by the Federal Aviation Administration for a modification to the neutral settings of the inboard and outboard ailerons and aft flap segments on Boeing 727 type aircraft; which is now incorporated into a noise abatement modification for Boeing 727 aircraft. It should be noted that the above two modifications to the Boeing 727 aircraft result in limiting trailing edge flap extension. 0034 An object of the present invention is to provide a mechanical means for an aircraft wing to attain optimal camber for the majority of the time it is in operational use, and yet allow normal operation of the wing leading and trailing edge devices. 0035 The aforementioned prior art, some of which is theoretical and some of which has practical applications, does not provide passive drag reduction and lift improvement utilizing the airfoil and the airfoil's trailing edge components originally supplied by the aircraft manufacturer. An object of the present invention is to increase airfoil efficiency, or the lift-to-drag ratio, employing existing major components of the aircraft wing to enhance the aerodynamics.

SUMMARY 0036 In accordance with the present invention a system of repositioning all wing trailing edge flight control surfaces to a predetermined position in order to obtain an increase in the lift-to-drag ratio, resulting in reduced fuel consumption for any distance flown.

OBJECT AND ADVANTAGES 0037 Accordingly, several objects and advantages of the present invention are: 0038 (a) to provide an airfoil with a new fixed camber resulting in a greater lift-to-drag ratio; 0039 (b) to provide an airfoil with increased aerodynamic efficiency without attaching any external devices to the trailing edge of the airfoil; 0040 (c) to provide an airfoil with an optimal camber for the majority of the time it is functioning and not restrict the operation of said airfoil's flight control surfaces; 0041 (d) to provide an airfoil with means for changing said airfoil's geometric profile without changing the shape or contour of any component of the airfoil; 0042 (e) to provide an airfoil with significant performance improvement through the use of all trailing edge devices on said airfoil; 0043 (f) to provide an airfoil for an aircraft which gives the aircraft the capability to climb to a higher initial cruising altitude; 0044 (g) to provide an airfoil for an aircraft which gives the aircraft an increased rate of climb; 0045 (h) to provide an airfoil for an aircraft that has superior aerodynamic efficiency while the aircraft is in a cruising mode; and 0046 (i) to provide an airfoil for an aircraft which reduces the quantity of fuel consumed by said aircraft over any given distance flown. 0047 Further objects and advantages are to provide an airfoil with increased lift and reduced drag characteristics that is able to lift an aircraft from a given surface to a higher altitude in any specific time; thus reducing perceptible sound decibel levels in the vicinity of the aircraft's departure. This airfoil's aerodynamic efficiency will also reduce total powerplant emissions as a result of the reduction of fuel consumed for a given flight. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

DRAWING FIGURES 0048 The drawings depict the present invention as applied to the left hand wing of a Boeing 737 type aircraft However, it is understood that all wings on an aircraft are treated identically. 0049 FIG. 1 illustrates the association and position of trailing edge flight control devices on the aircraft wing. 0050 FIG. 1A views the aircraft wing from behind with the trailing edge flaps extended. 0051 FIG. 2 is a profile depicting the inter-relationship of the trailing edge flap segments when retracted. 0052 FIG. 2A is a profile depicting the inter-relationship of the trailing edge flap segments when extended. 0053 FIG. 3 is a side view of aileron positions. 0054 FIG. 4 is a side view of aft flap positions. 0055 FIG. 5 is a perspective view of a self-adjusting extendible push-pull rod. 0056 FIG. 6 is an isometric view of this inventions modifications to the trailing edge flaps. 0057 FIG. 7 illustrates structure used to close a void in the trailing edge flaps. 0058 FIG. 8 is a profile of the mechanisms that position the outboard aft flap. 0059 FIG. 9 is a view looking down into the inboard mid flap depicting the mechanisms that position the inboard aft flap. 0060 FIG. 10 is a perspective view of a self-adjusting compressible push-pull rod. 1Reference Numerals In Drawings11trailing edge flaps12aileron13aircraft wing14fore flap15powerplant16mid flap18aft flap20aileron neutral position21aileron predetermined position22aft flap original position23aft flap predetermined position24original push-pull rod25self-adjusting extendible26alloy stoppush-pull rod28aft flap track31adjustable rod end32locking nut33sliding shaft34cylinder35flange36boss37internal spring40skin extension41splice42fastener43bulb seal44seal retainer50right-angled bellcrank52horizontal cam track54elongated bellcrank56cable driven drum58cam slot59configuration change60self-adjusting compressiblepush-pull rod

DESCRIPTIONPREFERRED EMBODIMENT 0061 A preferred embodiment of the airfoil of the present invention employs a multi-segmented trailing edge flap system equivalent to the flap system of a Boeing 737 type aircraft. The association of the trailing edge flaps 11 and ailerons 12 to the aircraft wing 13 is depicted in FIG. 1. The trailing edge flaps 11 of the Boeing 737 aircraft are composed of a section inboard and a section outboard of the under-wing mounted powerplant 15. The inter-relationship of the trailing edge flap segments, (fore flap 14, mid flap 16, and aft flap 18), is illustrated in FIG. 2 and FIG. 2A. Each section of aft flap 18 is positioned by two push-pull rods 24, and transits on two aft flap tracks 28 installed in the mid flap 16. 0062 The aileron neutral position 20 (FIG. 3) is altered to a predetermined position 21 situating the trailing edge of the aileron 12 below the unmodified neutral setting; utilizing standard maintenance and rigging practices for the aircraft involved. 0063 The aft flap segments 18 are relocated to a predetermined position 23 aft and below their original positions 22 as depicted in FIG. 4. This is accomplished by replacing the existing push-pull rods 24, which control the position of the aft flap segments 18, with distinctive self-adjusting extendible push-pull rods 25 (FIG. 5) of equal length. The forward, or retracted, travel of the aft flap 18 is limited by welding an alloy stop 26 (FIG. 6) on the aft flap tracks 28 which locates the aft flap 18 in its predetermined position 23 when the trailing edge flaps 11 are retracted. 0064 When static, the new rods 25 are of sufficient length to position the aft flap 18 as originally intended when the flaps 11 are extended. Both ends of the new rods 25 have adjustable rod ends 31 identical to the original rods 24, including locking nuts 32. A sliding shaft 33 and a cylinder 34 are manufactured from recognized aircraft quality alloys with properties that exceed the virtues of the original rods 24. The lengths of both the sliding shaft 33 and the cylinder 34 are greater than one half the length of the original rods 24. 0065 The sliding shaft 33 is solid and round, with a congruent flange 35 approximately equal in diameter to the inner diameter of the cylinder 34 and located at the opposite end of the shaft 33 from the rod end 31. The outside diameter of the shaft 33 is approximately equal to the diameter of an orifice in a boss 36. 0066 The cylinder 34 is round with an outside diameter approximately equal to the original rods 24. The cylinder 34 has a bored cavity of sufficient diameter and depth to accommodate the sliding shaft flange 35 and an internal spring 37. The depth of the bored cavity is calculated to allow internal spring 37 compression when the aft flap 18 engages the stop 26 on the aft flap tracks 28 during flap retraction; and normal aft flap 18 positioning upon flap extension. A boss 36 is threaded on the bored end of the cylinder 34 to provide a guide for the sliding shaft 33 and retain the internal spring 37. 0067 An internal spring 37 is installed around the sliding shaft 33 and between the flange 35 and the boss 36, inside the bored cavity of the cylinder 34. The length and rigidity of the internal spring 37 are calculated to provide accurate aft flap 18 position during flap extension, and spring 37 compression during flap retraction when the aft flap 18 engages the stop 26 on the aft flap track 28. 0068 Re-situating the aft flap 18 to the predetermined position 23 creates a void between the mid flap 16 and the aft flap 18 which disrupts the even aerodynamic surface of the aircraft wing 13. This void is eliminated by the addition of a skin extension 40 to the lower surface of the mid flap 16 (FIG. 6). The skin extension 40 is manufactured from the same material as the lower surface of the mid flap 16 and is of sufficient width to cover the void when the trailing edge flaps 11 are retracted. The skin extension 40 (FIG. 7) is mounted on the same plane as the lower surface of the mid flap 16 with a splice 41 that extends the entire span of the mid flap 16 and the skin extension 40. Current accepted aircraft maintenance and repair practices govern the gauge, width, and material properties of the splice 41; and the quantity, placement, and type of fastener 42 utilized. The aircraft's original bulbseal 43 and seal retainer 44 are then reinstalled on the skin extension 40 in a position to contact the leading edge of the aft flap 18 when the trailing edge flaps 11 are retracted. 0069 It becomes evident that the above described method and means: 0070 (a) allow the primary flight control surfaces of an aircraft wing to be operated as originally intended, 0071 (b) creates a unique airfoil geometric profile when the primary flight control surfaces of the wing are in the neutral, or normal, position, and 0072 (c) will improve the aerodynamic efficiency of an airfoil by increasing the lift-to-drag ratio.

OPERATION OF INVENTION 0073 This invention functions passively and operates through the utilization of aerodynamic principles. It is known from classical aerodynamic theory that a more highly cambered than usual trailing edge section will improve overall airfoil lifting efficiency and reduce the coefficient of drag. The desirable properties and efficiency of the airfoil are maximized during the vast majority of the time that the airfoil is operating. Special operational or flight procedures are not required; pilots and maintenance personnel will perform their respective duties in the same manner as they did previously. 0074 When use of the trailing edge flaps 11 is necessary, the internal spring 37 in the extendible push-pull rods 25 maintains an overall rod length equal to the original push-pull rods 24, assuring that the aft flap 18 is positioned as originally intended by the aircraft manufacturer. As the trailing edge flaps 11 are retracted for climbing and cruising the stops 26 on the aft flap tracks 28 limit the forward and upward travel of the aft flap 18 to it's predetermined position 23, and the extendible push-pull rods 25 lengthen in order to accommodate the remainder of the retraction motion of the mid flap 16 and fore flap 14. The skin extension 40 and the bulb seal 41 close the void between the mid flap 16 and aft flap 18 when the trailing edge flaps 11 are retracted; leaving the aft flap 18 in it's predetermined position 23. This increases the camber and extends the chord of the airfoil. The re-positioning of the aileron 12 to it's predetermined position 21 contributes to the new geometric profile of the airfoil.

ALTERNATIVE EMBODIMENT 0075 Another possibility with regard to repositioning the aft flap 18 to a predetermined position 23 for increased airfoil efficiency when the trailing edge flaps 11 are retracted utilizes the mechanisms that control the position of the push-pull rods 24 for aft flap 18 extension and retraction. 0076 The aft flap 18 of the outboard section of flaps 11 is positioned by a right-angled bellcrank 50 (FIG. 8) attached to the rod end 31 of each push-pull rod 24. The bellcrank 50 is allowed to pivot about a central point as a horizontal cam track 52, at the distal end of the bellcrank 50 from the rod end 31, imparts a forward or aft motion to the bellcrank 50 extremity attached to the rod end 31; thus dictating aft flap 18 position. The mid flap 16 of the inboard section of trailing edge flaps 11 contains an elongated bellcrank 54 (FIG. 9) that pivots about a point near a cable driven drum 56 with a cam slot 58. The end of the elongated bellcrank 54 proximate to the cable driven drum 56 has a lobe which travels in the cam slot 58 providing forward and aft movement to the opposite end of the bellcrank 54. The rod end 31 of the push-pull rod 24 is attached to the distal end of the bellcrank 54 from the cam slot 58. The forward and aft movement of the bellcrank 54 positions the aft flap 18 during trailing edge flaps 11 extension and retraction. 0077 A change to the configuration 59, of the right-angled bellcrank 50 and the elongated bellcrank 54, to provide an attach point for the push-pull rods 24 that is closer to the aft flap 18, would allow the aft flap 18 to be moved down and aft to it's predetermined position 23 when the trailing edge flaps 11 are retracted. The aft flap tracks 28 inherently limit the rearward travel of the aft flap 18 by design. The change to the configuration 59 of the bellcranks 50 and 54 would not allow full extension of the trailing edge flaps 11 utilizing the original push-pull rods 24, as they would push the aft flap 18 to the aft flap track 28 limit before the fore flap 14 and mid flap 16 reached full deployment; damaging components in the trailing edge flaps 11 system. 0078 This method requires replacing the original push-pull rods 24 with a self-adjusting compressible push-pull rod 60 (FIG. 10). The compressible rods 60 have the same material properties and components as the extendible rods 25. However, in this case the internal spring 37 is installed between the flange 35 and the bottom of the bored cavity in the cylinder 34, and it's length and rigidity are calculated to provide accurate aft flap 18 positions until spring 37 compression becomes necessary to allow the flaps 11 to be fully extended. When static the compressible rods 60 are of sufficient length to situate the aft flap 18 in it's predetermined position 23, and the combined lengths of the sliding shaft 33 and the cylinder 34 approximate the length of the original rods 24. Again, a void is created between the mid flap 16 and aft flap 18 when the flaps 11 are retracted. The void would be treated, as in the preferred embodiment, with a skin extension 40, bulbseal 43, and seal retainer 44; installed with a splice 41 and fasteners 42. 0079 As described in the preferred embodiment, the aileron neutral position 20 (FIG. 3) is altered to a predetermined position situating the trailing edge of the aileron 12 below the unmodified neutral setting. This is accomplished utilizing standard maintenance and rigging practices for the aircraft involved. 0080 This embodiment allows the aft flap 18 to be relocated to a predetermined position 23 when the flaps 11 are retracted, and assures correct aft flap 18 positions throughout the course of flaps 11 extension. The compressible rods 60 permit full extension of the fore flap 14 and mid flap 16 when the aft flap 18 reaches the limits of the aft flap tracks 28. The re-positioning of the aileron 12 to it's predetermined position 21 contributes to the new geometric profile of the airfoil.

Conclusions, Ramifications, and Scope of the Invention 0081 Thus the reader will see that the method employed and the attending mechanisms used to accomplish said method produce an airfoil with a lengthened chord and a redefined positive camber. This highly cambered trailing edge area of the airfoil will improve span wise loading, reduce drag, and enhance lifting efficiency. The increased lift-to-drag ratio results in decreased fuel consumption for any distance flown for the vehicle operating with said airfoil. In addition, the airfoil of the present invention imparts unto an aircraft the capability to climb to a higher initial cruising altitude at an increased rate of climb, and provides exceptional efficiency while the aircraft is in cruise flight. 0082 Furthermore, the present invention has the additional advantages in that: 0083 (a) it does not necessitate the addition of any external devices to the trailing edge of the airfoil; 0084 (b) it does not require the alteration or re-contouring any of the airfoil's flight control surfaces; 0085 (c) it permits normal operation of any leading edge or trailing edge apparatus inherent to the airfoil; 0086 (d) the reduction in fuel consumed by any vehicle employing said airfoil results in lower emissions from the vehicles powerplant(s) into the atmosphere; and 0087 (e) a higher rate of climb for an aircraft equipped with the airfoil of the present invention will reduce the perceptible sound decibel levels in the area below the aircraft. 0088 While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example the structure used to seal the void created between flap segments could be installed utilizing various techniques such as bonding, welding, or bracing with gussets; and structure material could be anything considered airworthy. The shape of the stop on the aft flap track can vary as long as it functions as intended; and it could be fabricated from metal, phenolic, or a durable composite material. The stop can be installed utilizing any structurally sound method; considering the intended purpose of the stop. As much as practical, the shape and substance of the extendible or compressible push-pull rods and their components can change; and the material properties and characteristics of the internal spring should change to accommodate different air loads or aircraft. 0089 As regarding other aircraft types, each distinct aircraft trailing edge system is modified differently in order to realize an optimal airfoil efficiency. A flap system employing a single flap would reposition that single flap when retracted; and a multi-segmented flap system only repositions the aft segment when the flaps are retracted. The precise means of accomplishing this repositioning will vary in accordance with the mechanisms used to extend and retract the trailing edge flaps of the aircraft wing. However, the use of extendible or compressible push-pull rods, and/or changing the contour or configuration of bellcranks, and eliminating voids or non-aerodynamic areas, are elements that could be incorporated. Aileron repositioning should be achieved using standard maintenance and rigging procedures for the aircraft involved. 0090 Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.