Document Type


Publication Date





Human Systems Integration involvesthe systematic consideration of tradeoffs in system structure or behavior, which affect sevenhuman-centered domains to optimize total system performance and life cycle cost.All too often, HSI is overlooked or poorly practiced, despite the specific directive within DoDI 5000.02 for program managers to plan for and conduct HSI. In the worst of cases, poor consideration of human capabilitiesandlimitations leads to errors, mishaps, and death or serious injury. One such human limitation in aviation is the inability of the pilot to maintain proper spatial orientationduring flight,asmismatches between the stimuli present during flight create an erroneous perception of aircraft attitude withrespect to the horizon.The consequences include preventable departures from controlled flight and unusual attitudes, unnecessary aircraft ejections, and controlled flight into terrain. Between 1993 and 2013, spatial disorientation contributed to12% of all Class A Mishaps, resulting in the lossof 65 aircraft and 101 lives. With a fatality rate of 24.9%, disorientation leads all Class A mishap causal factors.While it may not be feasible to prevent all spatial disorientation mishaps, itmay be possible to significantly reduce mishap rates throughproper tradeoff analysis, resulting in better total system performance and reduced life cycle costs. To that end, this paper will discuss the HSI domains applicable to spatial disorientation and provide a meta-analytical perspective on practicing HSI and its implications for disorientation prevention.