CP.I.I.R4

From the FAA library

• Pilot's Handbook of Aeronautical Knowledgep. 17-22
  Chapter 17: Aeromedical Factors › Vision in Flight › Night Blind Spot

  Night Vision There are many good reasons to fly at night, but pilots must keep in mind that the risks of night flying are different than during the day and often times higher. [Figure 17-16] Pilots who are cautious ... educated on night-flying techniques can mitigate those risks and become very comfortable and proficient in the task. Night Blind Spot It is estimated that once fully adapted to darkness, the rods are 10,000 times more sensitive to light…

• Pilot's Handbook of Aeronautical Knowledgep. 17-27
  Chapter 17: Aeromedical Factors › Flicker Vertigo › Night Landing Illusions

  Night Landing Illusions Landing illusions occur in many forms. Above featureless terrain at night, there is a natural tendency to fly a lowerthan-normal approach. Elements that cause any type of visual obscurities, such as rain, haze, or a dark ... runway environment, can also cause low approaches. Bright lights, steep surrounding terrain, and a wide runway can produce the illusion of being too low with a tendency to fly a higher-than-normal approach. A set of regularly spaced lights…

• Aeronautical Information Manualp. 8-1-7
  Chapter 8. Medical Facts for Pilots › Section 1. Fitness for Flight › 8-1-5. Illusions in Flight

  wider-than-usual runway can have the opposite effect, with the risk of leveling out high and landing hard or overshooting the runway. (c) Runway and terrain slopes illusion. An upsloping runway, upsloping terrain, or both, can create the illusion ... that the aircraft is at a higher altitude than it actually is. The pilot who does not recognize this illusion will fly a lower approach. A downsloping runway, downsloping approach terrain, or both, can have the opposite effect. (d) Featureless…

• Pilot's Handbook of Aeronautical Knowledgep. 17-24
  Chapter 17: Aeromedical Factors › Vision in Flight › Night Vision Protection

  This precaution increases the rate of dark adaptation at night and improves night visual sensitivity. Oxygen Supply Unaided night vision depends on optimum function and sensitivity of the rods of the retina. Lack of oxygen to the rods (hypoxia) significantly ... their sensitivity. Sharp clear vision (with the best being equal to 20–20 vision) requires significant oxygen especially at night. Without supplemental oxygen, an individual’s night vision declines measurably at pressure altitudes above 4,000 feet. As altitude increases…

• Pilot's Handbook of Aeronautical Knowledgep. 17-8
  Chapter 17: Aeromedical Factors › Health and Physiological Factors Affecting Pilot Performance › Visual Illusions

  Turn stopped Sensation of turning in opposite direction as moving fluid deflects hairs in opposite Inversion Illusion An abrupt change from climb to straight-and-level flight can stimulate the otolith organs enough to create the illusion of tumbling backwards ... known as “inversion illusion.” The disoriented pilot may push the aircraft abruptly into a nose-low attitude, which may intensify this illusion. Elevator Illusion An abrupt upward vertical acceleration, as can occur in an updraft, can stimulate the otolith organs…

• Pilot's Handbook of Aeronautical Knowledgep. 17-22
  Chapter 17: Aeromedical Factors › Vision in Flight › Dark Adaptation

  Looking off center can help compensate for this night blind spot. Along with the loss of sharpness (acuity) and color at night, depth perception and judgment of size may be lost. [Figure 17-17] Figure 17-17. Night blind spot ... Dark Adaptation Dark adaptation is the adjustment of the human eye to a dark environment. That adjustment takes longer depending on the amount of light in the environment that a person has just left. Moving from a bright room into…