Five helicopter accidents with evidence of material and/or design deficiencies

Most helicopter accidents are due to problems concerning flight operations, ground duties (mission planning and preparation), training and instructions. These are key issues within the current (European) strategies for greatly reducing the number of accidents in the next few years. However, when accidents occur the subsequent investigations should include or at least consider forensic engineering, even if only to eliminate possible causes like material defects, component and systems failures, and design deficiencies. To illustrate this, the present paper discusses five helicopter accidents with evidence of material and/or design deficiencies. The accidents concerned a Sikorsky S-61N (1974), an Aérospatiale Alouette III (1990), a Westland Lynx SH14D (1998), and two AgustaWestland EH101s (2004, 2006).

► Survey of five helicopter accidents.
► Fractography essential in all cases.
► Quantitative Fractography (QF) and non-LEFM and LEFM analyses for two failures.