Method of minimizing the attitude hump phenomenon and a rotary wing aircraft provided with stabilizer means therefor
AssigneeAirbus Helicopters
InventorsSylvie Borie, Samuel Leyder, Marc Allongue
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Abstract
A system and method of minimizing the attitude hump phenomenon of a rotary wing aircraft is provided. The rotary wing aircraft includes upper pitching-stabilizer and at least one lower pitching-stabilizer. The lower stabilizer is positioned in a wake of the upper stabilizer generated by a stream of air passing through the rotary wing and impacting against the upper surface of the upper stabilizer.
Claims20
A method of minimizing the attitude hump phenomenon relating to a rotary wing aircraft having an airframe extending longitudinally from a front end to a rear end, the method comprising:
- providing an upper pitching-stabilizer means and at least one lower pitching-stabilizer means;
- and
- positioning the lower stabilizer means offset towards the rear end from the upper stabilizer by a longitudinal distance being generally equal to a maximum longitudinal chord of the upper stabilizer means such that the lower stabilizer means is arranged in an aerodynamic shadow of a stream of air passing through said rotary wing and impacting against the upper surface of the upper stabilizer means such that the upper stabilizer means at least partially blocks the stream of air from the lower stabilizer means when the aircraft has a forward speed slower than a predetermined speed.
A rotary wing aircraft comprising:
- an airframe extending longitudinally from a front end to a rear end;
- an upper pitching-stabilizer means extending transversely from the rear end;
- and
- at least one lower pitching-stabilizer means, extending transversely from the rear end and offset towards the rear end from the upper stabilizer means by a longitudinal distance being generally equal to a maximum longitudinal chord of the upper stabilizer means and offset by an elevation distance being less than the longitudinal distance such that the lower stabilizer means is arranged in an aerodynamic shadow of a stream of air passing through said rotary wing and impacting against an upper surface of an upper stabilizer means such that the upper stabilizer means at least partially blocks the stream of air from impacting the lower stabilizer means when the aircraft has a forward speed slower than a predetermined speed.
A rotary wing aircraft having a primary rotor wing and a rear rotor, the aircraft comprising:
- an airframe extending in a longitudinal direction from a front end to a rear end;
- an upper stabilizer surface extending transversely from the rear end;
- and
- at least one lower stabilizer surface, extending transversely from the rear end and offset towards the rear end from the upper stabilizer surface by a longitudinal distance being generally equal to a maximum longitudinal chord of the upper stabilizer means such that the lower stabilizer surface is arranged in an aerodynamic shadow of an airstream generated by the primary rotary wing and impacting the upper stabilizer surface such that the upper stabilizer surface at least partially blocks the airstream from impacting the lower stabilizer surface,
- wherein the upper stabilizer surface and the lower stabilizer surface are located forward of the rear rotor in the longitudinal direction.
Dependencies are inferred from the claim text.