Abstract: Apparatus and methods are disclosed for designing and manufacturing a composite structure, such as a composite rotor blade spar or composite rotor blade. A first mold may define a first mold surface and a second mold may include a rigid layer and a heated layer secured to the rigid layer and defining a second mold surface. A plurality of heating elements embedded in the second mold may be activated according to different temperature progressions to cure portions of the uncured composite rotor blade positioned coextensive therewith. In some embodiments, the second mold defines a root portion and first and second branch portions. A shear web may be placed between the branch portions during curing. The blade spar may define a complete airfoil contour or have fairings secured thereto having lines extending therethrough to a tip jet. A tip jet mounting structure and blade root attachment apparatus are also disclosed.

Abstract: Apparatus and methods are disclosed for manufacture of a composite rotor blade spar having non-uniform wall thickness. Tooling for manufacturing include a first mold defining a first mold surface and a second mold comprising a rigid layer and a heated layer secured to the rigid layer and defining a second mold surface. A plurality of heating elements embedded in the second mold are activated according to a plurality of different temperature progressions effective to cure portions of the uncured composite blade spar positioned between the first and second mold surfaces coextensive with each heating element of the plurality of heating elements. In some embodiments, the second mold defines a root portion and first and second branch portions. A shear web is placed between the first and second branch portions and is bonded to a blade spar skin surrounding the second mold during curing of the blade spar skin.

Abstract: A rotor blade having conduits for supporting control lines is disclosed. The control lines extend from a rotor hub to a tip jet mounted near a distal end of the rotor blade. The conduits mount within leading and trailing edge fairings mounted to a blade spar. The conduits may be supported by bulkheads secured at discrete locations along the blade spar and secured to the leading and trailing edge fairings. The conduits may also be secured to support webs secured to the leading or trailing edge fairing and extending longitudinally therealong. The conduit may have a tapered inner surface and a tapered fitting may secure to the control line to engage the tapered inner surface.

Abstract: A rotor blade assembly is disclosed including a blade spar having a duct extending therethrough and having upper and lower surfaces. A mounting structure is secured to the blade spar and defines a fluid path in fluid communication with the duct. The mounting structure likewise has upper and lower surfaces. A tip jet is secured to the mounting structure in fluid communication with the fluid path. The blade spar and mounting structure abut one another at a joint and the upper surfaces of the blade spar and mounting structure lie on a common airfoil contour extending across the joint. The lower surfaces of the blade spar and mounting structure also lie on the common airfoil contour. One or both of the blade and mounting structure include a composite material. The mounting structure may include two portions secured to one another having a distal portion of the blade spar captured therebetween.

Abstract: A fairing system may be assembled about a rotor of a rotorcraft to present an aerodynamically quasi-static region that rotates in an airstream, as well as certain extensions that sweep through the airstream as the rotor hub passes through the air. A spherical interface between the extensions on the rotor hub fairing and the base or root portion of each blade fairing provides three degrees of freedom permitting lead-lag, flapping, and blade pitch pivoting in the blade, while still maintaining an aerodynamic profile that will minimize drag.

Abstract: A rotor blade having a detachable fairing is disclosed. The rotor blade includes leading and trailing edge fairings secured to the blade spar and one or more control lines extending between of the fairings and the blade spar. A detachable fairing extends from one or both of the leading and trailing edge fairings toward one of the distal and proximal ends of the blade spar. The detachable fairing and blade spar form an airfoil contour. The detachable fairing may secure to a tip jet attachment fitting at a distal end of the blade spar. A mounting structure including upper and lower plates may secure near a proximal end of the blade spar and the detachable fairing may secure to both the upper and lower plates to form all or part of an airfoil contour. The mounting structure may include a spherical seat engaging a spherical surface of a hub shroud.

Abstract: Apparatus and methods are disclosed for manufacture of a composite structure, such as a composite rotor blade spar or composite rotor blade. A first mold may define a first mold surface and a second mold may include a rigid layer and a heated layer secured to the rigid layer and defining a second mold surface. A plurality of heating elements embedded in the second mold may be activated according to different temperature progressions to cure portions of the uncured composite rotor blade positioned coextensive therewith. In some embodiments, the second mold defines a root portion and first and second branch portions. A shear web placed between the branch portions may be bonded to a blade skin positioned within the mold. The rotor blade may include a rotor blade spar having leading and trailing edge fairings secured thereto or the blade spar may define a complete airfoil contour.

Abstract: A fairing system may be assembled about a rotor of a rotorcraft to present an aerodynamically quasi-static region that rotates in an airstream, as well as certain extensions that sweep through the airstream as the rotor hub passes through the air. A spherical interface between the extensions on the rotor hub fairing and the base or root portion of each blade fairing provides three degrees of freedom permitting lead-lag, flapping, and blade pitch pivoting in the blade, while still maintaining an aerodynamic profile that will minimize drag.

Abstract: A rotor blade having a detachable fairing is disclosed. The rotor blade includes leading and trailing edge fairings secured to the blade spar and one or more control lines extending between of the fairings and the blade spar. A detachable fairing extends from one or both of the leading and trailing edge fairings toward one of the distal and proximal ends of the blade spar. The detachable fairing and blade spar form an airfoil contour. The detachable fairing may secure to a tip jet attachment fitting at a distal end of the blade spar. A mounting structure including upper and lower plates may secure near a proximal end of the blade spar and the detachable fairing may secure to both the upper and lower plates to form all or part of an airfoil contour. The mounting structure may include a spherical seat engaging a spherical surface of a hub shroud.

Abstract: An aircraft is disclosed having an engine and a propeller mounted to a fuselage. An empennage mounts to the aircraft and includes first and second horizontal stabilizers separated by a distance greater than the diameter of a stream tube of the propeller at the horizontal stabilizers. A rudder extends between the horizontal stabilizers and is positioned within the stream tube of the propeller. The rudder may mount to a first vertical stabilizer extending between the horizontal stabilizers. The horizontal stabilizers may be secured to second and third vertical stabilizers to form a duct having the rudder positioned within the duct. Additional rudders may mount to the second and third vertical stabilizers.