MUMBAI, India, Sept. 28 -- Intellectual Property India has published a patent application (202541026932 A) filed by Hindustan Aeronautics Limited on March 24, 2025, for Method To Fabricate Pitch Case Of Rotary Wing Aircraft Composite Tail Rotor Blade.
Inventor includes Dr. Vijaya Kumar K..
The application for the patent was published on September 25, 2026, under issue no. 39/2026.
Abstract: The present invention comprises a novel method to fabricate pitch case of composite tail rotor blade (Figure.1) for an advanced rotary wing aircraft. The pitch case (2) is fabricated uniquely due its geometrical complexity having tapered hollow structure to integrate members of the pitch change mechanism and embedded with the aerofoil section or the main body (3) of the rotor blade during fabrication and blades are made in pair, one each on both the side of a flex beam (1) The present invention incorporates a unique five step approach to fabricate high quality hollow tapered pitch case of the tail rotor without warpages, poor compaction, surface undulations, non uniform wall thickness and layer folds that provide strength to sustain multiple load paths and to increase the fatigue life of the rotor blade. The pitch case fabrication as per the present invention is fabricated using pitch case mandrel assembly (Figure.3) that comprises of a pre casted upper (5) and lower (6) silicon mandrels, upper (7) & lower (8) wedges and trailing edge (9) and leading-edge (10) wedges. All these are integrated to a pre cured composite flex beam (11). The glass prepreg layers are wrapped over the pitch case assembly and cured together, later these mandrels, wedges are removed from the cured pitch case to obtain equally stiff and strong hollow section to withstand mechanical stresses, including centrifugal forces, vibrations, and aerodynamic loads.
Disclaimer: Curated by HT Syndication.
