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A team from the USA rotorcraft industry, NASA, and academia was established to create a validated high-fidelity computational fluid dynamics (CFD) icing tool for rotorcraft. Previous work showed that an oscillating blade with a periodic variation in angle of attack causes changes in the accreted ice shape and this makes a significant change in the airfoil drag. Although there is extensive data for ice accumulation on a stationary airfoil section, high-quality icing-tunnel data on an oscillating airfoil is scarce for validating the rotorcraft icing problem. In response to this need, a two-dimensional (2D) oscillating airfoil icing test was recently performed in the Icing Research Tunnel at the NASA Glenn Research Center. Three leading-edge specimens for an existing 15-inch chord test apparatus were designed and instrumented to provide the necessary data for the CFD code validation.

Engineering plastics are now available for use on lightly loaded aircraft structure. These materials have excellent cost benefits as well as producibility benefits over their hand laidup predecessors. They are especially useful in the strut and nacelle areas where many of the fairings are attached for aerodynamic purposes only and may have rather complicated contours. In addition to lower costs, the manufacturing process is consistent, unlike hand laidup parts, which often require rework. In the strut and nacelle area one of the major requirements for all parts is sonic durability. This paper is intended to explain the test setup and test procedure for sonic testing of thermoplastics and thermosets and the results of the testing up to this point. Included in this explanation will be the assumptions made, the test setup, results of the testing and conclusions drawn from the testing.

Flight in icing for transport category aircraft certification presents a particularly challenging set of considerations to establish adequate safety commensurate with the associated risk while balancing design complexity and efficiency. A review highlighting important aspects of the regulatory evolution and guiding principles for flight in icing certification is presented, including the current standards and recent rulemaking activity.

Determining local ice crystal icing concentration factors in the region of the forward fuselage is critical for setting the Total Water Content levels for air data probe qualification testing. Simulation, modeling, and testing techniques for this concentration-factor phenomenon are still in their infancy, and there is currently not a significant amount of this type of analysis in the literature. A representative, 3D analysis was conducted using transport airplane geometry and flight conditions that explored the sensitivities resulting from parametric changes to flight and ice crystal icing conditions, particle modeling parameters, and bouncing effects.