title: Effects of FOV and aircraft bank on pilot head movement and reversal errors during simulated flight.
abstract: BACKGROUND
  Recent studies have shown that while flying under visual meteorological conditions (VMC) pilots tilt their head to keep the horizon stabilized on their fovea. This reflex, referred to as Opto-Kinetic Cervical Reflex (OKCR), may improve spatial awareness by establishing the horizon retinal image as a stabilized primary visual-spatial cue. Since the limited field of view (FOV) provided by helmet-mounted displays (HMDs) significantly decreases visual stimuli, the purpose of this research was to determine how reduced FOV affects head movements.
  
  
  OBJECTIVE
  As FOV is decreased, there will be a significant reduction in OKCR-induced head movement. Reduced FOV will also increase control reversal errors.
  
  
  METHODS
  Twelve pilots completed simulated flight tasks in a stationary dome. Head tilt, pitch, and yaw were examined as a function of aircraft bank and FOV (40 degrees, 60 degrees and 100 degrees circular). The number of control reversal errors was analyzed to investigate signs of spatial disorientation.
  
  
  RESULTS
  During VMC manuevers pilots exhibited significant OKCR; however there were no significant differences among the three levels of FOV. FOV significantly affected head pitch movements under both VMC and instrument meteorological conditions (IMC). Pilots yawed their heads in the direction of aircraft bank under VMC. Pilots committed 22 reversal errors out of 72 trials (30.55%). The magnitude of the error was largest for the 40 degrees FOV condition.
  
  
  CONCLUSIONS
  Pilots exhibit the OKCR under all tested levels of FOV and also make head yaw movements in order to keep the way point in sight during banking maneuvers. Pilots demonstrated stick reversal errors when transitioning from following a lead aircraft under both VMC and IMC conditions.
authors.affiliation: Wright State University, Department of Biomedical and Human Factors Engineering, Dayton, OH 45435, USA. jgalli@cs.wright.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Gallimore
authors.forename: N G
authors.initials: NG
authors.lastname: Brannon
authors.forename: F R
authors.initials: FR
authors.lastname: Patterson
authors.forename: J P
authors.initials: JP
authors.lastname: Nalepka
mesh_terms: D000704:Analysis of Variance; D001359:Aviation / Q000379:methods*; D015982:Bias; D003198:Computer Simulation; D019416:Head Movements / Q000502:physiology*; D006260:Head Protective Devices; D006801:Humans; D008889:Military Personnel / Q000523:psychology; D012018:Reflex / Q000502:physiology*; D012044:Regression Analysis; D012678:Sensation Disorders / Q000209:etiology* / Q000503:physiopathology* / Q000523:psychology; D013028:Space Perception / Q000502:physiology*; D014481:United States; D014796:Visual Perception / Q000502:physiology*