AI.II.B.K1
KnowledgeEnvironmental conditions that degrade vision.
From the FAA library
- 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 ... reduces 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…
- Chapter 7. Safety of Flight › Section 6. Potential Flight Hazards › 7-6-14. Flying in Flat Light, Brown Out Conditions, and White Out Conditions
Flying in Flat Light, Brown Out Conditions, and White Out Conditions a. Flat Light. Flat light is an optical illusion, also known as “sector or partial white out.” It is not as severe as “white out” but the condition causes ... pilots to lose their depth-of-field and contrast in vision. Flat light conditions are usually accompanied by overcast skies inhibiting any visual clues. Such conditions can occur anywhere in the world, primarily in snow covered areas but can also…
- Chapter 11: Night Operations › Night Vision › Factors Affecting Vision
flight deck and/or instruments, scratched and/or dirty instrumentation, use of flight deck red lighting, inadequate flight deck environmental control (temperature and humidity), inappropriate sunglasses and/or prescription glasses/contact lenses, and sustained visual workload during flight. Red light illumination distorts colors (magenta ... cyan pigment appears black) on aeronautical charts. Pilots should use it only where optimum outside night vision capability is necessary. Dim white flight deck lighting should be available when needed for map and instrument reading. ⦁ Monovision contact lenses (one contact…
- Chapter 5. Air Traffic Procedures › Section 4. Arrival Procedures › 5-4-22. Use of Enhanced Flight Vision Systems (EFVS) on Instrument Approaches
More information may be found at the FAA Flight Standards EFVS webpage at https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs400/afs410/efvs. l. Other Vision Systems. Unlike an EFVS that meets the equipment requirements of 14 CFR § 91.176, a Synthetic Vision System (SVS) or Synthetic Vision ... outside scene and also does not meet the equipment requirements for EFVS operations. A pilot cannot use a synthetic vision image on a head-up or a head-down display in lieu of natural vision to descend below DA/DH…
- Chapter 8. Medical Facts for Pilots › Section 1. Fitness for Flight › 8-1-6. Vision in Flight
Vision in Flight a. Introduction. Of the body senses, vision is the most important for safe flight. Major factors that determine how effectively vision can be used are the level of illumination and the technique of scanning ... other aircraft. b. Vision Under Dim and Bright Illumination. 1. Under conditions of dim illumination, small print and colors on aeronautical charts and aircraft instruments become unreadable unless adequate cockpit lighting is available. Moreover, another aircraft must be much closer…
- Chapter 17: Aeromedical Factors › Vision in Flight › Scanning Techniques
looking 10° above, below, or to either side of the object. [Figure 17-19] In this manner, the peripheral vision can maintain contact with an object. With off-center vision, the images of an object viewed longer than ... reach a photochemical equilibrium that prevents any further response until the scene changes. This produces a potentially unsafe operating condition. To overcome this night vision limitation, pilots must be aware of the phenomenon and avoid viewing an object for longer…