ISSN:
0308-0501
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Architecture, Civil Engineering, Surveying
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
This paper is based upon an actual post-crash investigation of a high-performance single-eingine aircraft that crashed in mountainous terrain resulting in a post-crah fire. A detailed metallurgical study of the fuel system separations was undertaken to identify which fittings or fuel lines had suffered mechanical damage during the initial impact sequence and which had been damaged by the post-crash fire or in subsequent handling of the wreckage. This paper discusses some of the basic metallurgical theories used in failure analyses of aluminum alloy components involved in post-crash fire studies. Its primary purpose is to discriminate between thermal effects of fire and mechanical overload, specifically for fuel system components. Metallurigical characterisitics cause certain specific signatures of ‘witness marks’ in mechanically induced speartions and different features in post-crash fire separations. Discussed are frequently observed metallurgical sigantures that may be used to evaluate post-crash, post-fire damage. Based on the metallurgical evidence and the principles described in this paper, it was obvious that the root cause of damage to these fuel system components was either thermal exposure during the post-crash fire or breakage after the fire during handling of the wreckage. Therefore, it was concluded that the fuel system components described herein had not been compromised during the inital impact, but rather had released fuel only after the post-crash fire. These principles can be utilized in similar investigations but it is important to recognize the chaotic nature of seveeere crashes and the wide range of possible damage features that may result. Each investigation must, of necessaity, be based upon both basic principles and an overall assessment of the quality of the evidence as well as the need to resolve what may appear to be conflicting or questionable features of the available evidence.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/fam.810190604
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