4.4 The Impact of Human Error on Aviation Safety      

            One of the most significant hazards to flight in low-light conditions is spatial disorientation and visual illusions. These issues can complicate nighttime flying and flying in low-visibility weather, particularly for inexperienced pilots. Spatial disorientation refers to the inability to accurately perceive the aircraft's position, attitude, or movement in space (Federal Aviation Administration, 2016, p. 17-6). Pilots rely on various sensory cues to navigate effectively. 

The visual system is crucial as pilots use their eyes to gauge the aircraft's orientation by focusing on the horizon's position. The somatosensory system provides essential feedback through the skin, muscles, nerves, and joints, allowing pilots to feel the effects of gravity. Additionally, the vestibular system, located in the inner ear, works similarly to an aircraft. As the fluid in the ear shifts across delicate hairs, it provides critical cues for positioning and motion, helping determine pitch, yaw, and roll (FAA, 2016, pp. 17-6). Understanding these systems is vital for maintaining control and ensuring safety while flying in low-light conditions.

When the body experiences a rapid shift in gravity due to a sharp maneuver or a loss of the horizontal field, as may occur during a dark storm or night flight, it can lead to sensory conflict, making it difficult for the pilot to orient the aircraft. Visual references are essential for a pilot's spatial orientation abilities. Central vision is used to gauge distances and infer the speed or depth of objects, while peripheral vision helps assess the motion of surrounding elements. However, when visual cues are compromised due to insufficient lighting during a night flight, over large bodies of water, or because of cloud cover and poor weather conditions, pilots must rely on their instrument readings to maintain proper spatial orientation (FAA, 2016, pp. 17-6).

Pilots can experience illusions such as the Leans or the Coriolis Illusion when changes to the vestibular system occur. These illusions can cause pilots to be disoriented in their vertical posture and altitude awareness. The illusions line Somatotropic Illusion caused by an aircraft rapidly accelerating can disorient a pilot to believe they are in a nose-up attitude, causing them to compensate in a fatal nose-low dive. When visual references are lost outside an aircraft, pilots can experience illusions such as the Black Hole illusion that occurs when low to no light conditions are experienced, causing a pilot to believe the plane to be at a higher altitude than they are (FAA, n.d.).

These types of illusions pose serious risks, particularly for inexperienced pilots. Therefore, training on how to counteract spatial disorientation is essential. Inexperienced pilots should refrain from flying in low-light conditions and poor-visibility weather until adequately trained. Pilots should check weather conditions and study flight routes before flying. When navigating in low-visibility scenarios, reliance on flight instrumentation for accurate readings of altitude, positioning, and speed becomes crucial to ensure safety (National Transportation Safety Board [NSTB], n.d.).

References

Federal Aviation Administration [FAA]. (2016). Pilot’s Handbook of Aeronautical Knowledge:

 Faa-H-8083-25B. EISENBRAUNS. 

FAA. (n.d.). Spatial Disorientation Visual Illusions. FAA. 

https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/spatiald_visillus.pdf 

National Transportation Safety Board [NSTB]. (n.d.). Visual Illusions: The Ground May Be 

Closer Than It Appears. NSTB. 

https://www.ntsb.gov/Advocacy/safety-alerts/Documents/SA-052.pdf