Molded Erosion Protection Systems for Composite Rotor Blades

Naval aircraft operate in hostile environments that include sandy or dusty landing zones and/or severe sand/rain storms. Helicopters and other vertical/short takeoff and landing (VTOL/ STOL) aircraft such as the V-22 Osprey are expected to endure thesesevere environments without rapid erosion to the leading edge of their rotor blade. The U.S. Navy is interested in removing the metallic leading edge strip and replacing it with innovative erosion-resistant coating materials/concepts directly over thecomposite leading edge of the rotor blade. Hontek has developed extremely rain and sand erosion resistant polyurethane elastomers under prior SBIR contracts. Hontek proposes to mold these highly erosion resistant elastomers directly onto the compositeleading edge, or mold them into individual boots for installation later onto the composite leading edge. In addition, this proposal will investigate the adhesive bonding, the removal and repair of the erosion protection systems. Fast and easy removal andrepair techniques will be developed. Another task will investigate the use of nanoparticles to increase the erosion resistance of the elastomers. The proposed molded erosion protection systems have universal applications to all types of composite rotorblades, propeller blades and radomes. It is anticipated that this effort will provide a light weight and conformable erosion protection system for the composite leading edge on current and emerging VTOL/STOL aircraft such as V-22 Osprey. This effort willeliminate the need for frequent inspection to detect incipient fatigue cracks in the metal leading edge, reduce acquisition and operating costs, enhance blade fatigue life, improve mission safety, reduce need for spares, simplify field serviceability andreduce total ownership cost (TOC).