The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1992
Filed:
Apr. 11, 1991
Steven D Weiner, Orange, CT (US);
Thomas J Toner, Milford, CT (US);
John J Occhiato, Derby, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
An integrated empennage structure is provided for a helicopter embodying a ducted fan antitorque device. The integrated empennage structure includes a shroud that houses the ducted fan antitorque device, a vertical stabilizer, and a horizontal stabilizer. The aerodynamic configurations and/or orientations and the spatial orientations of the shroud, vertical stabilizer, and the horizontal stabilizer are interactively related and optimized to provide yaw stability and directional control and pitch stability and maneuverability required for helicopter flight operations. The shroud is spatially orientated at a first predetermined cant angle with respect to the vertical plane of symmetry of the helicopter fuselage such that the ducted fan antitorque device provides lateral antitorque thrust to counteract main rotor assembly induced torque and a positive vertical force component to enhance the overall lift capability of the helicopter. The vertical stabilizer is spatially orientated at a second predetermined cant angle with respect to the vertical plane and aerodynamically configured with a predetermined camber and/or aerodynamically orientated with a predetermined angle if incidence to provide an antitorque force during forward flight regimes that allows the ducted fan antitorque device to be effectively off-loaded and a negative vertical force component that complements the negative vertical force provided by the horizontal stabilizer. The aerodynamic functioning of the vertical stabilizer allows aerodynamic configuration and/or the aerodynamic orientation of the horizontal stabilizer to be reduced and facilitates the attachment of the horizontal stabilizer in substantially symmetrical relation to the vertical stabilizer. The horizontal stabilizer is aerodynamically configured and orientated to optimize the dynamic pitch stability of the helicopter in the forward flight regimes.