FATIGUE FAILURE OF THE DE-HAVILLAND COMET-I

The de Havilland Comet I entered service in 1952, and became the first commercial airliner to be powered by jet engines. It was introduced a s the flagship aircraft on the routes of the British Overseas Airways Corporation, and was hailed as a triumph of British engineering. Howev er there were a number of accidents involving this aircraft, culminati ng, in 1954, in the loss of two aircraft in similar circumstances. The se were Comet G-ALYP near Elba, and Comet G-ALYY near Naples. A Court of Inquiry was convened, and the task of discovering the cause of thes e accidents was given to the Royal Aircraft Establishment al Farnborou gh. The investigation explored a number of avenues, and finally gave s tructural failure of the pressure cabin brought about by fatigue as th e cause of the accidents. The use of fracture mechanics methods not us ed in 1954 has enabled the analysis of these fatigue cracks to be made , and the initial defect size has been estimated to be approximately 1 00 mu m in the case of G-ALYP. This is not incompatible with the manuf acturing techniques of the time, and information regarding cracks in t he cabin identified during manufacture. (C) 1997 Elsevier Science Ltd.