Patent ID: 8926280
Filing Date: 2015-01-06
Classification: B64C

Abstract:
1. A tail rotor of a rotary wing aircraft, the tail rotor being shrouded and having a central hub and a shrouded duct, the tail rotor having a rotor blade in a fibre-reinforced composite design, comprising: a blade section having a blade skin and a blade body, wherein the blade section forms an aerodynamically effective profile; a blade tip that faces the shrouded duct and faces away from the central hub of a drive device of the rotor; a coupling section which faces towards the central hub, with an attachment device for a separate tension-torque-transmission element, the coupling section defining one single attachment hole, spar tapes that go all the way through the blade section from one end to the other, the spar tapes made of unidirectional fibre material and having an essentially rectangular cross-section, the single attachment hole defined by a cylindrical hole-face with a generally constant diameter extending through the coupling section, and a single bolt for attaching the rotor blade to the central hub of the drive device using the single attachment hole, the single bolt also attaching a separate control tube to the rotor blade using the single attachment hole, the rotor blade and the control tube being separately formed, and the single attachment hole forming a hole-face by intersecting the planes of the spar tapes, the coupling section having a cured section and the single attachment hole being formed only in the cured section of the coupling section wherein the single attachment hole in the coupling section of the rotor blade is formed by a process comprising the step of machining the single attachment hole into the cured section of the coupling section of the rotor blade.