Steve Henderson

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In the U.S. in 2008, accidents resulting from VFR flight into IMC accounted for 2% of all general aviation (GA) accidents, but 8% of all fatal GA accidents. Furthermore, 88% of VFR into IMC accidents were fatal, compared to 17% of other aviation accidents. Dissonance theory is a model of attitude change associated with making difficult choices. Attitude change reduces cognitive dissonance arising from favourable aspects of a not-chosen alternative and unfavourable aspects of a chosen alternative, through spreading of alternatives. Under dissonance theory, pilots in marginal weather who repeatedly revisit their choice to either continue their flight or divert to an alternate destination progressively distort their perception of weather conditions, making them more likely to commit decision-making errors leading to VFR into IMC accidents. Many aspects of general aviation are consistent with factors that increase spreading of alternatives. Dissonance theory resolves inconsistent results from simulator-based studies of weather decision-making.