Backgrounders

Backgrounder

Release of the Safety Issues Investigation Report on Post-Impact Fires Resulting from Small-Aircraft Accidents

On May 30, 2000, the pilot of a Cessna 177B Cardinal was attempting to take off from a grass airstrip at Calling Lake, Alberta. The aircraft struck trees during the initial climb, struck the ground, and burst into flame. The post-impact fire resulted in the two occupants being exposed to smoke and flame for some time. One occupant was fatally injured due to the effects of fire, and one sustained serious burns. The investigation (A00W0109) was completed and the final report was released to the public on January 4, 2002.

The accident investigation identified fuel system crashworthiness as a small-aircraft safety deficiency. In light of that finding, the Board identified a need to examine the extent to which fuel system crashworthiness and other safety deficiencies contribute to the risks associated with post-impact fires in otherwise survivable accidents, and to consider the risk control options available to mitigate those risks.

Transportation Safety Board of Canada (TSB) investigators gathered statistics on 521 aviation accidents that occurred in Canada between 1976 and 2002 inclusive, that involved powered, small aircraft, and that resulted in post-impact fires. The results indicated that post-impact fires occur in approximately 4 per cent of accidents involving small aircraft; however, these accidents account for approximately 22 per cent of the fatalities and 11 per cent of the serious injuries caused by all accidents. Overall, 6.2 per cent of fatal injuries and 3.8 per cent of serious injuries that resulted from small-aircraft post-impact fire accidents were related to fire.

Although post-impact fires are a well-known safety concern, past attempts to change certification requirements have been unsuccessful. The TSB investigators reviewed the history of post-impact fires, and noted that both the National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA) have attempted to address this issue in the past, through special studies and notices of proposed rule making. However, cost-benefit analysis negated the proposed safety measures.

The TSB maintains that additional defences to prevent post-impact fires and to reduce fire-related injuries can and should be introduced. The implication of design improvements on new aircraft will be significant, and even more significant on existing designs. The process to enhance current design standards will require considerable effort by Transport Canada and the Federal Aviation Administration, and cooperation by their international counterparts to ensure harmonization of any new standards and guidelines.

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The Safety Issues Investigation, SII A05-01, and the Communiqué are also available on this site.