Bird strike by artificial and real birds on aircraft leading edges

Abstract

Aircraft wing and stabiliser leading edges need to be analysed against bird strike. Incident statistics reveal that these components are set out to this type of impact which leads to damage. Hence, airworthiness certification asks for safety measures. This approach is similar to other aircraft or helicopter [1] components which are prone to bird strike. Here are discussed horizontal and vertical stabiliser designs to improve the integrity after bird strike. The designs were developed for hybrid laminar flow control (HLFC) i. e. incorporate a suction technology to improve laminarity at the leading edge. At detail scale, particular a splitter or deflector design with a tailored skin single duct (TSSD) with a variable porosity was shown. Two horizontal stabiliser demonstrators with microperforated titanium skins were highlighted as these were applied for the first back-to-back testing of artificial bird versus real bird at a full-scale level. The identical structures were impacted each under identical boundary conditions by the different bird types resulting in comparable deformation and damage pattern. The latest DLRRAB (DLR reinforced artificial bird) artificial bird in ellipsoidal shape and a duck with a weight of 3.6 kg (8 lbs) for both was applied. The advantages of artificial birds and the particular challenges of testing with real birds were compared on the basis of load measurements and impact on hemispherical leading edges of aluminium. A possible path from real over biofidelic to artificial birds for representative and test-to-test repeatable testing together with numerical simulation was sketched. The approach with artificial bird models may offer an alternative method to animal experiments.