Sikorsky Aircraft Corporation

United Technologies Corporation

Robert D Beatty

Thomas Alan Egolf

David H Hunter

Robert C Moffitt

Justin J Thomas

Eric Lucien Nussenblatt

Peter F Lorber

Timothy A Krauss

Fred W Kohlhepp

Ashish Bagai

Chris Paul Butler

Edmond F Kiely

Nicholas Charles Tuozzo

Gary Law

Shawn Westfall

Michael C Lonergan

Edward Reed

John K Karpowich

Nick Tuozzo

An aircraft includes an airframe, an extending tail, a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly, and a translational thrust system positioned at the extending tail. The translational thrust system provides translational thrust to the airframe. An upper hub fairing is positioned at the upper rotor assembly. A lower hub fairing is positioned at the lower rotor assembly. A shaft fairing is disposed between the upper hub fairing and the lower hub fairing. The upper hub fairing is substantially sealed to the shaft fairing and the lower hub fairing is substantially sealed to the shaft fairing.

Sealed hub and shaft fairing for rotary wing aircraft

A main rotor blade assembly for a rotary wing aircraft is provided including a main rotor blade root region, a main rotor blade inboard region arranged outboard of said main rotor blade root region, a main rotor blade main region arranged outboard of said main rotor blade inboard region, and a main rotor blade tip region arranged outboard of said main rotor blade main region. At least one of chord, twist, sweep, airfoil shape, and thickness/chord of the main rotor blade assembly has been optimized to achieve balanced high speed forward flight and hover relative to both efficiency and high thrust capability.

Dual rotor, rotary wing aircraft

A stationary ground tube for use in an aircraft rotor fairing includes a first cylindrical portion including a first bore aligned along a longitudinal axis, the cylindrical body portion having a tubular body from a first end to a second end; and a second cylindrical portion coupled to the first cylindrical portion, the second cylindrical portion including a second bore aligned along the longitudinal axis. The second cylindrical portion is coupled to the aircraft rotor fairing via at least one attachment device.

Non-rotating stationary ground tube for a wind fairing

A main rotor blade incorporating a rotor blade tip region having a tip chord and a tip taper such that the ratio of the main rotor blade chord to the tip chord is approximately 0.30. The tip taper ratio preferably providing an approximately 28% area of reduction in said outer 10% of said blade span. The tip region preferably further including a hover optimized high lift airfoil and a tip sweep that reaches a constant value of approximately 30 degrees along the quarter chord line.

Rotor blade tip planform

A mounting arrangement (100) for a Variable Diameter Rotor blade assembly (16) having an outer blade segment telescopically mounting to a torque tube member (24), and connecting means (70) for transferring centrifugal loads of the outer blade segment (22) to a rotor hub assembly (18). The outer blade segment (22) includes a spar member (30) having a longitudinal axis (26) and defining an internal channel (62) for accepting the torque tube member (24) and the connecting means (70). The mounting arrangement (100) couples the connecting means (70) to the spar member (30) and includes a restraint surface (86) formed within the spar member (30) and a restraint assembly (68) disposed in combination therewith. The restraint surface (86) is disposed inboard of the tip end (90) of the spar member (30) and in a plane oriented transversely of the longitudinal axis (26). The restraint assembly (68) is disposed internally of the spar member (30) and includes a bearing block (102) mounting to the connecting means (70) and having upper and lower transverse slots (104a, 104b) formed therein. The restraint assembly (68) further comprises a load transfer member (106) disposed in combination with the transverse slots (104a, 104b) and the restraint surface (86) for transferring centrifugal loads to the connecting means (70). A sidewall aperture (134) is formed in the spar member (30) and proximal to the restraint surface (86) to facilitate installation of the load transfer member (106) in the transverse slots (104a, 104b).

Mounting arrangement for variable diameter rotor blade assemblies

A rotor blade subassembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a flexbeam, an integrated torque tube/spar member, and an aerodynamic fairing or rotor blade. The flexbeam is a laminated composite structure that reacts centrifugal loads and a majority of the bending loads of the rotor assembly. The flexbeam has a spanwise predetermined linear twist so that the pretwisted flexbeam is unstrained during specified forward flight conditions. The integrated torque tube/spar member is formed as a continuous, filament wound tubular composite structure having high torsional and bending stiffness that provides a continuous torsional load path and facilitates load coupling between the rotor blade and the pretwisted flexbeam. The spar segment of the functions as the primary structural member of the rotor blade subassembly and, is operative to react all bending, torsional, shear, and centrifugal dynamic loads of the rotor assembly. The torque tube segment reacts all torsional loads and some of the bending loads of the rotor assembly. The rotor blade is fabricated from a high modulus composite material and has a high aerodynamic taper such that the tapered rotor blade has a low outboard mass, a high inboard stiffness, and a high chordwise frequency. The high chordwise frequency allows the rotor assembly to be operated over a weaker modal response zone. The tapered rotor blade includes a triangularly shaped trailing edge segment that is responsive to the aerodynamic pressures encountered during operation of the shrouded counter-rotating rotors.

Rotor blade subassembly for a rotor assembly having ducted, coaxial

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Trumbull, CT, United States of America

Robert D Beatty