Spatial Orientation Modeling: Expanding the Helicopter Envelope

Abstract

For the past 25 years we have used traditional spatial orientation models together with flight data recordings to analyze and predict pilot orientation in aviation mishaps for which there is no apparent mechanical failure or in which spatial disorientation is suspected as a cause of the mishap. The model has been verified in rare mishaps where surviving aircrew have verified predicted perceptions and provided probable causation of several air transport mishaps for NTSB investigations especially dealing with the somatogravic illusions associated with go-around maneuvers. It was thought that helicopters did not have sufficient acceleration to produce the somatogravic illusion. There have been two recent interesting mishaps one which was clearly a somatogravic illusion (aircraft flight recorder data and cockpit voice recorder) and a second high profile mishap (Kobe Bryant) with almost identical flight path and similar degraded visual environment. These mishaps will be examined from the perspective of the recently revised perceptual model to show how the positive feedback nature of the somatogravic illusion can provide overwhelmingly compelling pitch-up sensations to the somatosensory and vestibular sensations even while the pilot is applying 40 plus degree nose down control inputs and looking at the orientation instrumentation. The recent model revisions also provide multisensory options with novel technologies to prevent this type of mishap. The revised and expanded model will assist our DoD safety centers, the FAA and the NTSB in the analysis of future mishaps. Furthermore, the model with all sensory systems now included provides indications of the best technology combinations to be implemented for future cockpits, especially as full automation is becoming more prevalent.