Aviation Partners, Inc.

The Boeing Company

Other

C. R. Bard, Inc.

Gratzer, Richard L.

Gratzer, Louis B.

Louis B Gratzer

Walter B Gillette

A method for improving performance in an aircraft having a winglet coupled to a wing, the winglet having a leading edge and a trailing edge continuously transitioning from a leading edge and trailing edge of the wing. The method includes coupling a wing tip to the winglet. The wing tip may include a curved leading edge from the winglet leading edge to a leading end point, a curved trailing edge from a winglet trailing edge to a trailing end point, and an end segment connecting the leading end point and the trailing end point. The end segment may be swept back from the trailing end point to the leading end point at an end segment angle.

Wing tip with optimum loading

A method of improving performance of an aircraft, including attaching a wing tip to a wing of the aircraft. The wing tip includes a winglet and a ventral fin. The winglet includes a winglet leading edge, a winglet trailing edge, an adapter section, a transition section attached to the adapter section, a blade section attached to the transition section, and a first tip section attached to the blade section. The ventral fin is coupled to the winglet at an attachment location adjacent the transition section. The ventral fin includes a second tip section. The wing has a wing leading edge and a wing trailing edge in a wing chord plane. Attaching the wing tip to the wing includes connecting the adapter section to the wing such that the winglet leading edge continuously transitions from the wing leading edge, and the winglet trailing edge continuously transitions from the wing trailing edge.

Wing tip with winglet and ventral fin

A split winglet configured for attachment to a wing tip of a wing. The split winglet may include an upper winglet extending from the wing tip above a chord plane of the wing and a ventral fin projecting below the chord plane. The upper winglet and the ventral fin may include tip configurations. At least one of the upper winglet tip configuration and the ventral fin tip configuration may be provided by a curved blade cap attached thereto. The curved blade cap may include a leading edge having a first curve with a first radius, and a trailing edge having a second curve with a second radius different from the first radius. The curved blade cap may also include a distal segment oblique to the first curve and the second curve.

Split blended winglet

An airplane including a wing and a wing tip attached to an end of the wing. The wing has a wing leading edge and a wing trailing edge in a wing chord plane. The wing tip includes a winglet and a ventral fin. The winglet has a winglet leading edge continuously transitioning from the wing leading edge, and a winglet trailing edge continuously transitioning from the wing trailing edge. The winglet leading edge may be swept rearward. The winglet includes an adapter section attached to the end of the wing, a transition section attached to the adapter section, a blade section attached to the transition section, the blade section extending above the wing chord plane, and a first tip section attached to the blade section. The ventral fin may be coupled to the winglet at an attachment location adjacent the transition section, and extends below the wing chord plane.

A wing tip designed for attachment to a winglet of an aircraft, the winglet coupled to a wing of the aircraft and having a leading edge and a trailing edge continuously transitioning from a leading edge and trailing edge of the wing. The wing tip may include a curved leading edge from the winglet leading edge to a leading end point, a curved trailing edge from a winglet trailing edge to a trailing end point, and an end segment connecting the leading end point and the trailing end point. The end segment may be swept back from the trailing end point to the leading end point at an end segment angle.

A split winglet is disclosed having a first generally upward projecting wing end, and a second generally downward projecting wing end. The second generally downward projecting wing end may be integrally formed with the first generally upward projecting wing end to form a winglet assembly or may be separately attached onto an existing upwardly curved winglet.

An airplane, including a wing and a spiroid wing tip coupled to an end of the wing. The wing includes a wing leading edge and a wing trailing edge. The spiroid wing-tip includes an enclosed loop, which includes a beginning section, an ending section, and a middle section. The beginning section includes a leading edge generally continuous with the wing leading edge. The ending section includes a trailing edge swept rearward with respect to the wing trailing edge. The middle section is between the beginning section and the ending section, and includes a portion extending above a chord plane of the wing.

Split spiroid

The spiroid wing tip according to embodiments of the invention including a continuous segmental assembly having a closed loop frontal profile comprising a lower near vertical segment, a horizontal segment, a vertical segment, a second horizontal upper segment, and a near vertical segment. Accordingly to some embodiments of the invention, the spiroid profile is lowered with respect to the wing chord plane, such that a portion of the spiroid wing tip extends below the wing chord plane.

A wing incorporating a wing tip with a curved leading edge and a curved trailing edge to minimize induced drag for a given wing form is disclosed. The curve of the leading and trailing edges of the wing tip may be described generally as parabolic, elliptic, or super elliptic. A finite tip segment may be included with a sweep angle between the end of the curved leading edge and the end of the curved trailing edge. The wing tip may also include a spanwise camber.

A split winglet configured for attachment to a wing of an airplane. The split winglet may include an upper winglet smoothly extending from the wing tip above a chord plane of the wing and a ventral fin projecting below the chord plane from a lower surface of the upper winglet. The upper winglet may include a transition section which curves upward from the wing tip into a substantially planar section. Upper and lower surfaces of the upper winglet may be bounded by leading and trailing edges which are swept toward an airstream direction, parallel with the chord plane, and curve toward the airstream direction before terminating at a point distal of the wing tip. Similarly, upper and lower surfaces of the ventral fin may be bounded by leading and trailing edges which curve toward the airstream direction and terminate at a point distal of the wing tip.

The blended winglet is a wing-like device comprising a blended lifting surface attachable to each airplane wing tip so as to achieve minimum induced drag for a given surface size. The device consists of a nearly planar, straight section joined to the wing tip through a curved transition section designed to obtain an optimum aerodynamic loading. Surface streamwise cross sections are airfoils having appropriate thickness, camber and twist variations. In a critical departure from the usual winglet design approach, the sensitive transition section features a smoothly varying chord distribution which blends smoothly and continuously with the wing and with the adjoining straight section. In the transition section the leading edge sweep angle is limited to 65.degree. or less and the airfoil nose camber is correspondingly increased to accommodate the high sweep. The transition section also features limited in-plane curvature (i.e., large radius) to accommodate a large chord variation and to provide a practical means of achieving optimum aerodynamic loading. It also minimizes aerodynamic interference and undesirable flow separation and compressibility effects. Specific mathematical guidelines for the selection of winglet geometry are presented as a design framework for achieving maximum drag reduction and performance improvement while maintaining favorable characteristics over a range of operating conditions.

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Seattle, WA, United States of America

Louis B Gratzer