Abstract : This report updates the survey of U.S. Army helicopter accidents (1987-92) to include fiscal years 1993 through 1995. Those accidents in which spatial disorientation (SD) was considered to have played a major role were identified and compared to those in which SD played no part. In addition, an attempt was made to identify the factors behind each SD accident together with potential solutions. Of the 970 accidents now on the database, 30% were considered to have had SD as a major or contributory factor. Of particular note is the increased incidence of SD during helicopter operations during night aided flight. SD remains an important source of attrition of Army helicopter operations, costing an average of $58 million and 14 lives each year. The contribution of SD accidents to the overall accident rate is not getting smaller. The increase in risk associated with the use of night vision devices when compared to day flying is of particular concern. Recommendations are made in the following four areas: (1) education, (2) training, (3) research, and (4) equipment. In addition, control factors are discussed both on an individual, U.S. Army, and triservice basis.