Share Email Print

Proceedings Paper

Primary rotary-wing DVE-associated flight safety risk factors (Conference Presentation)
Author(s): Morris R. Lattimore

Paper Abstract

During Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF), there were 375 non-combat rotorcraft losses from October 2001 to September 2009. Human factors issues accounted for 78% of these non-combat losses, with controlled flight into terrain (CFIT) and night/degraded visual environment (DVE) as the leading human factor loss causes. This high percentage is reflective of the low survivability rate of DVE/night-based mishaps. Normal human visual sensitivity has been shown to be highly variable under low luminance, low contrast conditions (Lattimore, 2017). Furthermore, Thibos et al. (2002) demonstrated significant structural aberration, with accompanying decreased image quality in a normal population of dilated healthy eyes. Additionally, Watson (2015) computed widely varied human optical point spread functions in normal, dilated eyes. Finally, Bartholomew et al. (2016) assessed visual sensitivity under varied luminance in 234 healthy collegians; only 4.1% of the photopic 20/20 acuity responders were predictive of mesopic acuity responsiveness. Based on these data, nearly all aviators may be at increased risk for poor DVE-related visual and flight performance. Therefore, the greatest risk factor that Army aviators are facing when confronted with DVE conditions is perhaps the visual performance status of their own eyes. Contrast sensitivity testing under mesopic naturally-dilated, night conditions using any of the contrast sensitivity tests available, could be used to determine one’s native or base-line capability under DVE conditions. The systematic compilation of such data could prompt the military services to re-evaluate their vision performance standards, and restructure awareness training.

Paper Details

Date Published: 14 May 2019
Proc. SPIE 11019, Situation Awareness in Degraded Environments 2019, 1101903 (14 May 2019); doi: 10.1117/12.2517093
Show Author Affiliations
Morris R. Lattimore, U.S. Army Aeromedical Research Lab. (United States)

Published in SPIE Proceedings Vol. 11019:
Situation Awareness in Degraded Environments 2019
John (Jack) N. Sanders-Reed; Jarvis (Trey) J. Arthur III, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?