Characterisation of the realistic impact

This paper describes a study to characterise the impact threat to aircraft from runway debris. This work investigated the likelihood of an event excee ding a critical impact energy; it did not address the probability of an eve nt occurring. Runway debris was collected from six airfields and parameters such as size fraction, mass, density, bluntness and material type were cha racterised. The distribution of the stone mass against frequency was accura tely modelled and based on this, an expression was developed for the probab ility of an impact exceeding a critical level during a single take-off or l anding. By considering the probability of a 50J impact from runway debris a s a once in a lifetime event, the implication is that the actual threat is significantly more than the currently perceived threat. This study provides the foundations for more comprehensive studies and will give the designers improved understanding of the threat to aircraft from runway debris.