Role of near-miss bird strikes in assessing hazards

Abstract

Management of problem wildlife within the airfield environment is a difficult job. Today's Bird-Animal Aircraft Strike Hazard (BASH) program managers require as much information as possible to accomplish their tasks. Bird censuses and actual bird-strike events in and around the air operations area are used to make airfield management decisions and to assess the risk of bird hazards to aircraft. Both types of information are sampled rather sparsely. Avian radar is now being used as a new tool to provide continuous sampling of bird activity that significantly supplements visual censuses. The measure of risk used today is commonly expressed as the ratio of the number of bird strikes per 100,000 flying hours. While important, this measure of risk is relatively insensitive to improvements in safety measures that do not result in dramatically fewer bird strikes. Stated differently, a reduction in safety or an increase in risk (which reflects an increased likelihood of bird strikes occurring) is not anticipated, but, rather, it is calculated after the fact when increases in bird strikes have been experienced. As a result, BASH managers are at a disadvantage because they can respond only after bird strikes occur. To address this deficiency, we introduce a new method for assessing risk that is based on near-miss events that complements risk calculations based on reported bird strikes. Recent advances in commercially available, digital avian tracking radars enabled biologists to automatically monitor and assess near-miss events. Near-miss events occur much more frequently than bird strikes. A combined dataset of bird strikes and near-misses provides BASH managers with a more responsive metric to evaluate the success of their program over time than by using only the bird-strike dataset.