Abstract

INTRODUCTION: The performance and comfort of aircrew using stereoscopic displays viewed at a near distance over long periods of time is now an important operational factor to consider with the introduction of aerial refueling tankers using remote vision system technology. Examples include the USAF KC-46, RAAF KC-30, JASDF KC-767, and RNLAF KDC-10. Existing vision standards for Flying Class III aircrew with scanner duty, including aerial refueling operators, were designed for viewing real objects at long distances and may not be adequate for stereoscopic displays viewed at near distances.

METHODS. The Operational Based Vision Assessment Laboratory coordinated with the Air Force KC-46
Directorate, Boeing, and Flight Safety International to develop an aerial refueling operator remote vision system simulation. We also developed a comprehensive set of stereo acuity and ocular alignment measures, which included current standard measures, as well as several experimental vision tests. Fifteen subjects participated in one experiment to evaluate the effect of 2D, stereoscopic, and hyperstereoscopic camera configurations on refueling performance. In a second experiment, 27 subjects were selected such that about one-third clearly met current standards, one-third satisfied waiver criteria, and one-third failed current standards and waiver criteria for stereo acuity and ocular alignment. The relationship between vision test results and refueling performance was evaluated.

RESULTS. The results of Experiment 1 showed that the use of stereoscopic cameras clearly improved performance on average. The results of both experiments show that individuals with poorer quality of vision perform worse and report greater levels of discomfort.

CONCLUSION. The relationship between visual performance metrics and operationally relevant refueling
performance and self-reported eye-strain is reported in detail. Coarse measures of stereo acuity, and standard measures of ocular alignment, such as phorias, may not be adequate for screening aircrew using new technologies such as the KC-46 aerial refueling operator remote vision system.