Abstract: Apparatus for playing a board game based on airplane flight concepts and geographical relationships among countries of the world. Spaces are provided on a board for the movement of symbolic elements representing airplanes, with the number of spaces moved determined by chance, subject, however, to specific instructions affecting the movement of the symbolic elements, as determined by the directions of certain of the spaces on the board. At least four (4) stacks of cards are provided, with each card providing a specific flight destination or good or bad information affecting the flight movement on the board, either towards or from the numerous airports located on the board. The object of the game is for a player to be the first to move his symbolic element or airplane to the total number of airports agreed upon by the players before the game starts.

Abstract: A tennis racquet having a polar moment of inertia similar to conventional length racquets, but being longer than conventional racquets with the same or larger size strung surface. Having the same polar moment of inertia as a well playing conventional racquet gives it the same "feel" but with greater reach, and, if desired, a larger strung surface.

Abstract: An improved diffuser for fluid flow compressors which utilizes alternately swept diffuser vanes.

Abstract: A tennis racket frame is constructed primarily of an elongated tubular member having a wall thereof consisting of a plurality of concentric layers of high tensile strength fibers impregnated and bonded together by binder resin to produce a hollow cored tennis racket. The method includes forming a plurality of string holes in the head portion of the racket, during or prior to the molding operation. The holes are formed by separating the fibers around the location of the hole by passing pointed penetrating tools through the frame in the area which will form the head portion thereof, and either retaining the tool in position in the holes during molding, or replacing the tools with positioning pins or grommets prior to the molding operation. If the pins are utilized they may be removed after molding of the racket is complete, and if grommets are utilized they become integrally attached to the racket and provide additional support for the strings.

Abstract: A tennis racket frame is constructed primarily of an elongated hollow tube member having a wall thereof consisting essentially of a plurality of concentric layers of high tensile strength fibers impregnated and bonded together by binder resin, at least two of the layers being helical windings of opposite unidirectional hands, and the head portion of a racket frame having a groove molded therein to receive the loop portions of the strings in recessed relation to the surrounding surface areas of the frame. The frames are made by a method including the use of a special mandrel on which the layers of fiber are wound under controlled conditions providing extra material in the head portion which is formed into the wall of the grooved portion of the head without affecting the overall sectional dimensions of the frame.

Abstract: A tennis racket frame is constructed primarily of an elongated hollow tube member having a wall thereof consisting essentially of a plurality of concentric layers of high tensile strength fibers impregnated and bonded together by binder resin, at least two of the layers being helical windings of opposite unidirectional hands, and the head portion of a racket frame having a groove molded therein to receive the loop portions of the strings in recessed relation to the surrounding surface areas of the frame. The frames are made by a method including the use of a special mandrel on which the layers of fiber are wound under controlled conditions providing extra material in the head portion which is formed into the wall of the grooved portion of the head without affecting the overall sectional dimensions of the frame.

Abstract: A jet engine disposed at and preferably in front of the tip end of an airplane wing with exhaust flow intercepting and rotating counter to tip vortex flow to reduce vortex induced drag, the angle of rotation of exhaust flow being cyclically variable to dissipate the vortex flow. The tip engine assists in powering the aircraft.