摘要: Abstract The severe operating conditions for components in military aircraft lead to a wide range of failure modes and introduce many factors which can influence those failures. As result, the accident investigator or analyst may need explore issues more widely than might be case with systems benign controlled environments. Complicating are increasing age fleets, as result rising cost fleet replacement, reluctance inability OEMs provide impartial technical support, widespread use materials processes near their stress environment limits, an effort achieve that last little bit operational performance. DSTO provides analysis investigation support Australian Defence Force (ADF) has developed strong capability adviser on aviation failures, part because absence major manufacturer but also long history ADF self-reliance. This presentation brief overview Australia, then uses two recent examples illustrate fundamental tenet i.e., “all damage must explained”. how full required, even cases where appear likely principal factors. first example is drawn from into collision helicopters, demanded one most technically challenging investigations ever undertaken, ultimately, by developing new methods, it was possible remarkable level certainty about event. aspect chosen illustrates approach adopted resolve some apparently anomalous features wreckage. Resolution these drew heavily understanding over years carbon-fibre composite components. second growing emphasis taking “whole system” view, relates serious incident fuel tank ignited wiring system failure. problem resolving sequences when number scenarios assessed. In this case, earlier development, years, assessment failures paid off, very detailed opened up elsewhere fleet.