Experimental evaluation of bird strikes in urban air mobility

Abstract Since the Wright brothers demonstrated the first powered, sustained, and controlled flight in 1903, the airspace has been shared between birds and humans. Novel aircraft and advanced mobility concepts such as urban air mobility (UAM) are emerging in full swing. In that concept, a safe and efficient aviation transportation system will use highly automated aircraft that will transport passengers or cargo at low altitudes within and between metropolitan regions. To accomplish these missions, new types of aircraft which are sometimes known as air taxis are being developed. A successful integration of these aircraft into existing airspace is complicated and needs to take into account various aspects. One of these is the risk of wildlife strikes in general and bird strikes in particular. While bird strike constitutes a risk to any type of aircraft, the risk is predicted to be higher in case of air taxis. The proposed operational cruising altitude of air taxis is lower resulting in higher probability of collision as these are the altitudes where birds typically fly. In addition, air taxis are smaller in size and have lower certification requirements compared to conventional aircraft. As a result, the severity of damaging bird strikes is higher. To assess the risk and formulate suitable regulations, an extensive analysis is required providing more quantitative insight into the bird strike challenge. Therefore, a theoretical model of bird strike to quantify the impact force exerted due to a strike by considering different bird and aircraft-related parameters was developed previously. This paper aims to validate this theoretical model experimentally. While impact forces have been extensively studied for bird strikes in case of conventional aircraft, this work seeks to apply these principles in a novel context, where traditional aircraft standards may not fully address the unique challenges posed by air taxis. The paper presents a methodology for implementing an experimental setup, allowing for the theoretical impact force model to be fully validated and providing insights into the bird strike influencing parameters. A test matrix containing 7 test cases, 9 test scenarios, and 135 iterations is formulated to conduct the bird strike experiment, and the influencing parameters are considered for theoretical model verification. The paper closes with the presentation of the experimental results for validating the theoretical model which indicate 92.89 % conformance of experimental results with the theoretical model.