Attentional issues with helmet-mounted displays in poor visibility helicopter flight

Kurzfassung

Helicopter flight in reduced visibility due to poor weather conditions is highly demanding and often endangering flight safety due to high pilot workload, low situation awareness and spatial disorientation. Helmet-mounted displays (HMD) featuring enhanced and synthetic vision can provide pilots with symbology in their forward field-of-view to facilitate an accurate perception of the environment. When equipped with a head-tracker, HMD allow the symbols to be perfectly aligned with the outside scene. This is usually referred to as visual conformance. So far DLR has developed and investigated 2D and 3D symbology concepts for HMD within the scope of an expert online survey on obstacle and route designs, simulator trials and actual flight tests. Based on the findings a new en-route symbology as well as an advanced conformal landing zone representation were developed recently. To evaluate these concepts and to investigate selected designs from the online questionnaire a simulator study will be conducted with civil and military helicopter pilots until the end of April 2014. It is of interest to what extent the concepts support pilots in poor visibility compared to a state-of-the-art baseline condition with regard to task and flight performance, situation awareness and workload. The study will comprise an extensive analysis of human factors aspects, particularly focusing on attentional issues associated with binocular HMD and conformal symbology use. It will be investigated how attention can be selected, focused and divided between different display locations and the environment effectively, hence to what extent various tasks can be performed successfully during the flight depending on display type, visibility, event expectancy and task complexity. Moreover, psychophysiological measurements will be taken during the trials. Finally, objective flight performance will be analyzed as well as subjective helmet ratings on perceptual, visual, and somatic aspects, and system usability will be assessed. The paper will firstly illustrate the prominence of the new symbology concepts from a human factors standpoint, secondly provide details on the conducting of the study, and finally present and discuss selected results with regard to attentional aspects.