Despite decades of research, spatial disorientation, which is the incorrect perception of one’s orientation relative to gravity, remains one of the leading causes of aviation mishaps. In this mini-review, we highlight the role of the vestibular system towards generating disorientation. Specifically, in the absence of other cues, the brain is incapable of distinguishing between the acceleration caused by a static force such as gravity from that experienced in an accelerating vehicle, which leads to an ambiguity leading to acceleration being wrongly interpreted as tilts. Finally, because vestibular signals interact with autonomic, respiratory, and vascular regulation, we propose multimodal physiological monitoring as a testable research strategy for characterizing unstable self-motion estimation, while emphasizing that percept-specific detection requires controlled labeling and prospective validation.