SPATIAL DISORIENTATION-IMPLICATED ACCIDENTS IN CANADIAN FORCES, 1982-92

In a recent survey of CF18 aircrew human factors, 44% of pilots report ed experience with spatial disorientation (SD), of whom 10% had experi enced more than 3 episodes. In order to investigate further, we have c ompleted a retrospective study of SD-implicated category A accidents ( where an aircraft is destroyed, declared missing, or damaged beyond ec onomic repair) in the Canadian Forces (CF) during 1982-92. An overview of all SD occurrences (including accidents and incidents) across airc raft types is also presented. information was gathered concerning the genesis and severity of disorientation so that research effort and pil ot training could be appropriately implemented. Mishap investigation s ummaries involving category A accidents where SD was implicated were o btained from the CF Directorate of Flight Safety and reviewed. We also examined in detail the Board of Inquiry Reports of these accidents. T he role of disorientation in these accidents was assessed. There were 62 category A accidents between 1982-92 and, in 14, SD had been assign ed as a possible cause factor in the accident records. When divided in to the categories of Recognized SD (RSD), Unrecognized SD (USD), and I ncapacitating SD (ISD), all but two fell into the category of USD (the pilots were unaware of the disorientation). Of the SD accidents, 11 i nvolved a total loss of 24 lives. The majority of the accidents happen ed during the day, and pilots' cumulative flying experience did not ap pear to be a significant factor. According to our assessment, there we re two episodes of vestibular origin, involving the somatogravic illus ion. Three episodes of disorientation occurred over frozen lakes, one over glassy water, and one over ocean. Two accidents occurred during t actical training involving more than one aircraft. The causes of two a ccidents remain undetermined, with SD listed along with other possible causal factors. The suggestion follows that more research effort and pilot education and training should be placed on somatogravic illusion s and visual limitations under adverse flying conditions, and pilots s hould be made more aware of these 14 accident scenarios.