NVG (under construction, not ready for use)

Question 1

(Eye anatomy)

The order light enters the eye, and transmits image to the brain.

Answer 1

(1) cornea
(2) pupil
(3) iris
(4) lens
(5) retina
(6) optical nerve
(7) brain

Question 2

(Eye anatomy)

The cornea is

Answer 2

a circular, transparent protective tissue that projects forward and protects the eye.

Question 3

(Eye anatomy)

The pupil is

Answer 3

the opening (black center portion) in the center of the iris.

Question 4

(Eye anatomy)

The pupil allows

Answer 4

the light to enter the eye to stimulate the retina.

Question 5

(Eye anatomy)

The iris is

Answer 5

the round, pigmented (colored) membrane of the eye surrounding the pupil.

Question 6

(Eye anatomy)

The iris adjusts

Answer 6

the size of the pupil by using its ciliary muscles, which are attached to the pupil.

Question 7

(Eye anatomy)

When the pupil dilates (enlarges) under low light levels, it allows more light to enter the eye to further stimulate the 1)_________. When the pupil constricts (becomes smaller) under high light levels, it decreases the amount of light entering the eye, avoiding oversaturation (stimulation) of the 2)________.

Answer 7

1) retina
2) retina

Question 8

(Eye anatomy) The lens is a transparent, biconvex membrane located behind the pupil. The lens then directs (refracts) the light upon the retina (the posterior or rear portion of the eye).

Answer 8

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Question 9

(Eye anatomy) The retina is a complex, structured membrane, consisting of 10 layers called the Jacob’s membrane. The retina contains many tiny photoreceptor cells, called rods and cones.

Answer 9

11

Question 10

(Eye anatomy) Once light stimulates the retina, it produces a chemical change within the photoreceptor cells. When the chemical change occurs, nerve impulses are stimulated and transmitted to the brain via the optic nerve.

Answer 10

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Question 11

(Eye anatomy) Night Blind Spot- Occurs when the fovea becomes inactive under darkness or with low-level illumination, central vision becomes less effective and a night blind spot (5 to 10 degrees wide) develops.

Answer 11

11

Question 12

(Eye anatomy) This results from the concentration of cones in the fovea centralis and parafovea, the area immediately surrounding the fovea of the retina. The night blind spot should not be confused with the physiological blind spot (the so-called day blind spot) caused by the optic disk.

Answer 12

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Question 13

(Eye anatomy) Because of the night blind spot, larger and larger objects will be missed as distance increases. To see things clearly at night, an individual must use off-center vision and proper scanning techniques. Utilize the “Off-Center” vision technique to compensate.

Answer 13

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Question 14

(Eye anatomy) Day or Physiological Blind Spot-The physiological (day) blind spot is present all the time, not only during the day. This blind spot results from the position of the optic disk on the retina. The optic disk has no light-sensitive receptors. The physiological blind spot covers an area of approximately 5.5 to 7.5 degrees and is located about 15 degrees from the fovea.

Answer 14

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Question 15

(Eye anatomy) Compensated by binocular vision, each eye compensates for the blind spot in the optic disk of the opposite eye.

Answer 15

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Question 16

Name the 3 types of vision

Answer 16

Photopic, Mesopic, Scotopic

Question 17

Photopic vision is

Answer 17

used during daylight or when a high level of artificial illumination exists. The cones concentrated in the fovea centralis of the eye are primarily responsible for vision in bright light. Because of the high light level, rhodopsin is bleached out and rod cells become less effective. Sharp image interpretation and color vision are characteristic of photopic vision.

Question 18

Mesopic vision is

Answer 18

used at dawn, at dusk, and during full moonlight. Vision is achieved by a combination of cones and rods. Visual acuity steadily decreases as available light decreases. Color perception changes because the cones become less effective. As cone sensitivity decreases, crewmembers should use off- center vision and proper scanning techniques to detect objects during low light levels.

Question 19

Scotopic vision is

Answer 19

experienced under low light levels. Cones become ineffective, resulting in poor resolution of detail. Visual acuity decreases to 20/200 or less. This enables a person to see only objects the size of or larger than the big “E” on visual acuity testing charts from 20 feet away. (A person must stand at 20 feet to see what can normally be seen at 200 feet under daylight conditions.) Also, color perception is lost. A night blind spot in the central field of view appears at low light levels. The night blind spot occurs when cone-cell sensitivity is lost.

Question 20

Several visual problems or conditions affect night vision. These include

Answer 20

presbyopia, night myopia, myopia, hyperopia and astigmatism.

Question 21

Presbyopia- This condition is

Answer 21

part of the normal aging process, which causes the lens of the eye to harden.

Question 22

Night Myopia- (explain)

Answer 22

Myopic individuals do not see distant objects clearly; only nearby objects are in focus for them. Because of this, slightly nearsighted (myopic) individuals will experience visual difficulty at night when viewing blue-green light that could cause blurred vision. Also, image sharpness decreases as pupil diameter increases.

Question 23

Myopia- (explain)

Answer 23

When a myopic person views an image at a distance, the actual focal point of the eye is in front of the retinal plane (wall), causing blurred vision. Thus, distant objects are not seen clearly; only nearby objects are in focus. The problem is referred to as nearsightedness.

Question 24

Hyperopia- (explain)

Answer 24

Error in refraction, the lens of the eye does not focus an image directly on the retina. When an individual with hyperopia views a near image, the actual focal point of the eye is behind the retinal plane (wall), causing blurred vision. The problem is referred to as farsightedness.

Question 25

Astigmatism- Astigmatism is

Answer 25

an unequal curvature of the cornea that may cause an out-of-focus condition. If, for example, an astigmatic person focuses on power poles (vertical), the wires (horizontal) will be out of focus in most cases.

Question 26

DARK ADAPTATION (DSSTT) define -

Answer 26

Dark adaptation is the process by which the eyes increase their sensitivity to low levels of illumination.

Question 27

DARK ADAPTATION (DSSTT) Starting level- • the lower the starting level of illumination, the less time is required for adaptation. • Each person adapts to darkness in varying degrees and at different rates. • Exposure to intense sunlight for 2-5hrs decreases visual sensitivity for up to 5hrs. • Cumulative effect- the rate of dark adaptation and degree of night visual acuity decrease. May persist for several days.

Answer 27

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Question 28

DARK ADAPTATION (DSSTT) Sensitivity- • When fully dark-adapted rods become 10,000 times more sensitive than at the start. • Through a dilated pupil, total eye sensitivity becomes 100,000 times more sensitive.

Answer 28

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Question 29

DARK ADAPTATION (DSSTT) Time to Dark Adapt- 30 to 45 min under minimal lighting conditions. Time to Readapt After High intensity Lighting- several to 45min

Answer 29

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Question 30

(SPATIAL DISORIENTATION) define -

Answer 30

Spatial disorientation is an individual’s inability to determine his position, attitude, and motion relative to the surface of the earth, or significant objects. i.e. Trees, poles, or building during a hover. When it occurs, pilots are unable to see, believe, interpret, or prove the information derived from their flight instruments.

Question 31

(SPATIAL DISORIENTATION) 3 types

Answer 31

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Question 32

(SPATIAL DISORIENTATION) most dangerous type?

Answer 32

1

Question 33

(SPATIAL DISORIENTATION)

Answer 33

Type I (UNRECOGNIZED)- A disoriented aviator does not perceive any indication of spatial disorientation. In other words, he does not think anything is wrong. What he sees or thinks he sees is corroborated by his other senses. Type I disorientation is the most dangerous type of disorientation. The pilot unaware of a problem fails to recognize or correct the disorientation, usually resulting in a fatal aircraft mishap.

Question 34

(SPATIAL DISORIENTATION)

Answer 34

Type II (RECOGNIZED)-The pilot perceives a problem (resulting from SD). The pilot may fail to recognize it as SD.

Question 35

(SPATIAL DISORIENTATION)

Answer 35

Type III (INCAPACITATING) - The pilot experiences such an overwhelming sensation of movement that he cannot orient himself by using visual cues or the aircraft instruments. Not fatal if co-pilot can gain control of the aircraft.

Question 36

(EQUILIBRIUM MAINTENANCE) Visual System- The visual system is the most important in maintaining equilibrium and orientation. 80% of our orientation information comes from the visual system. • IMC- must rely on instruments for spatial orientation. • Demands disciplined training

Answer 36

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Question 37

VISUAL ILLUSIONS (FFF CRASH SCAR) “FFF”?

Answer 37

“Flicker Vertigo” “Fascination (Fixation)” “False Horizon Illusion”

Question 38

VISUAL ILLUSIONS (FFF CRASH SCAR) “CRASH”?

Answer 38

“Confusion with Ground Lights” “Relative Motion” “Altered Planes of Reference” “Height - Depth Perception Illusion”

Question 39

VISUAL ILLUSIONS (FFF CRASH SCAR) “SCAR”?

Answer 39

“Size-Distance Illusion” “Crater Illusion” “Autokinesis” “Reversible Perspective Illusion”

Question 40

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 40

Flicker Vertigo- Flicker vertigo may be created by helicopter rotor blades or airplane propellers interrupting direct sunlight at a rate of 4 to 20 cycles per second. Flashing anticollision strobe lights, especially while the aircraft is in the clouds, can also produce this effect. Viewing a flickering light can be both distracting and annoying, could produce seizures in those rare individuals who are susceptible to flicker-induced epilepsy. Solution - Turn off light source

Question 41

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 41

Fascination (Fixation) - Fascination, or fixation, flying can be separated into two categories: task saturation and target fixation. Task saturation may occur during the accomplishment of simple tasks within the cockpit. Crew members may become so engrossed with a problem or task within the cockpit that they fail to properly scan outside the aircraft. Solution - Refrain from staring at objects too long; scan

Question 42

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 42

False Horizon Illusion- The false horizon illusion occurs when the aviator confuses cloud formations with the horizon or the ground. An aviator may perceive the cloudbank below to be horizontal although it may not be horizontal to the ground; thus, the pilot may fly the aircraft in a banked attitude. Solution - Conduct a proper scan of instruments and other visual cues

Question 43

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 43

Confusion with Ground Lights- Confusion with ground lights occurs when an aviator mistakes ground lights for stars. This illusion prompts the aviator to place the aircraft in an unusual attitude to keep the misperceived ground lights above them. Solution - Conduct a proper scan, both aided and unaided

Question 44

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 44

Relative Motion- Relative motion is the falsely perceived self-motion in relation to the motion of another object. This illusion can be encountered during flight in situations such as formation flight, hover taxi, or hovering over water or tall grass. Solution-Proper scanning, experience and knowledge of the occurrence

Question 45

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 45

Altered Planes of Reference- In altered planes of reference the pilot has an inaccurate sense of altitude, attitude, or flight-path position in relation to an object so great in size that the object becomes the new plane of reference rather than the correct plane of reference, the horizon. A pilot approaching a line of mountains may feel the need to climb although the altitude of the aircraft is adequate. Solution - Perform map recon to determine height of obstacle, and search for true plane of reference

Question 46

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 46

Structural Illusions- Structural illusions are caused by the effects of heat waves, rain, snow, sleet, or other visual obscurants. A straight line may appear curved when it is viewed through the heat waves of the desert. The curvature of the aircraft windscreen can also cause structural illusion. This illusion is due to the refraction of light rays as they pass through the windscreen. Solution - Experience and knowledge

Question 47

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 47

Height - Depth Perception Illusion- The height-depth perception illusion is due to a lack of sufficient visual cues and causes an aircrew member to lose depth perception. Flying over an area devoid of visual references—such as desert, snow, or water—will deprive the aircrew member of his perception of height. The aviator, misjudging the aircraft’s true altitude, may fly the aircraft dangerously low in reference to the ground or other obstacles above the ground. Solution - Trust instruments and scan horizon

Question 48

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 48

Size-Distance Illusion- The size-distance illusion is the false perception of distance from an object or the ground, created when a crew member misinterprets an unfamiliar object’s size to be the same as an object that he is accustomed to viewing. This illusion can occur if the visual cues, such as a runway or trees, are of a different size than expected. An aviator making an approach to a larger, wider runway may perceive that the aircraft is too low. Solution - Experience and knowledge of the occurrence

Question 49

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 49

Crater Illusion- The crater illusion occurs when aircrew members land at night, under NVG conditions, and the IR searchlight is directed too far under the nose of the aircraft. This will cause the illusion of landing with up-sloping terrain in all directions. Solution - Proper use of landing and search light, knowledge of occurrence, and proper scanning

Question 50

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 50

Autokinesis- Autokinesis primarily occurs at night when ambient visual cues are minimal and a small, dim light is seen against a dark background. After about 6 to 12 seconds of visually fixating on the light, one perceives movement at up to 20 degrees in any particular direction or in several directions in succession, although there is no actual displacement of the object. Solution - Avoid fixating on objects, develop a good scan.

Question 51

VISUAL ILLUSIONS (FFF CRASH SCAR)

Answer 51

Reversible Perspective Illusion- At night, an aircraft may appear to be going away when it is, in fact, approaching a second aircraft. This often occurs when an aircraft is flying parallel to another’s course. Therefore, it is difficult to tell the direction of the aircrafts travel. Solution-proper scanning technique and the 3-r’s: red on the right is returning.

Question 52

(VESTIBULAR SYSTEM) Inner ear contains the vestibular system, which contains the motion- & gravity detecting sense organs. Located in the temporal bone, on each side of the head.

Answer 52

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Question 53

(VESTIBULAR SYSTEM) Each vestibular consist of 2 distinct structures; semicircular canals / vestibule proper, which contain the otolith organs.

Answer 53

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Question 54

(VESTIBULAR SYSTEM) Vestibule Proper- The otolith organs are small sacs located in the vestibule. Sensory hairs project from each macula into the otolithic membrane, an overlaying gelatinous membrane that contains chalklike crystals, called otoliths. They respond to gravity & linear accelerations/decelerations. Changes in position of the head, relative to the gravitational force, cause the otlithic membrane to shift position on the macula. The sensory hairs bend, signaling a change in head position.

Answer 54

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Question 55

(VESTIBULAR SYSTEM) Semicircular Canals- They sense changes in an angular acceleration. The canals will react to any changes in roll, pitch, or yaw attitude. The endolymph fluid in the canals moves with inertial torque resulting from angular acceleration in one of three planes. The motion of the fluid bends the cupula which moves the hairs of the hair cells situated beneath the cupula. This movement stimulates the vestibular nerve & these impulses are transmitted to the brain where they are interpreted as rotation of the head.

Answer 55

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Question 56

Vestibular Illusions are either ___________ or ___________.

Answer 56

“Somatogyral Illusions” “Somatogravic Illusions”

Question 57

Somatogyral Illusions- Are caused when

Answer 57

angular accelerations & decelerations stimulate the semicircular canals.

Question 58

Somatogravic Illusions- are caused from

Answer 58

changes in linear acceleration & gravity that stimulate the Otolith Organs.

Question 59

3 types of Somatogyral Illusions are

Answer 59

“Leans” “Graveyard Spin” “Coriolis Illusion”

Question 60

3 types of Somatogravic Illusions are

Answer 60

“Oculogravic” “Elevator” “Oculoagravic”

Question 61

Leans- The most common form. The pilot fails to perceive angular motion. During continuous straight-& level flight, the pilot will correctly perceive that he is straight & level. However, a pilot rolling into or out of bank may experience perceptions that disagree with the reading on the attitude indicator & other instruments. To counter the falsely perceived position, the pilot will lean his body until the false sensation leaves.

Answer 61

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Question 62

Graveyard Spin- Usually occurs in fixed-wing aircraft. If you enter a spin & remain in it for several seconds, the semicircular canals will reach equilibrium; no motion is perceived. Upon recovering from the spin, you undergo deceleration, which is sensed by the semicircular canals. You then have a strong sensation of being in a spin in the opposite direction even though the flight instruments contradict that perception. If deprived of external references, you may disregard the instruments & make control corrections against the falsely perceived spin. The aircraft will then enter a spin in the original direction.

Answer 62

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Question 63

Coriolis Illusion- The most dangerous of all, occurs whenever a prolonged turn is initiated & the pilot makes a head motion in a different geometrical plane. When a pilot enters a turn & then remains in the turn, the semicircular canal corresponding to the yaw axis is equalized. The endolymph fluid no longer deviates, or bends, the cupula. If the pilot initiates a head movement in a geometrical plane other than that of a turn, the yaw axis semicircular canal is moved from the plane of rotation to a new plane of nonrotation. The fluid then slows in that canal, resulting in a sensation of a turn in the direction opposite that of the original turn. Simultaneously, the two other canals are brought within a plane of rotation. The fluid stimulates the other two other cupulas. The combined effect of the coupler deflection in all three canals creates the new perception of motion in three different planes of rotation: yaw, pitch, & roll. The Pilot experiences an overwhelming head-over-heels tumbling sensation.

Answer 63

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Question 64

Oculogravic- Occurs when an aircraft is accelerated or decelerates in a forward direction. Inertia from linear acceleration causes the otolith organs to sense a nose-high altitude. A pilot correcting for this illusion without cross checking the instruments would most likely dive the aircraft, catastrophic during an approach. This illusion does not occur if adequate references are outside.

Answer 64

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Question 65

Elevator Illusion- This occurs during upward acceleration. Because of inertia, the pilot’s eyes track downward as his body tries, through inputs supplied by the inner ear, to maintain visual fixation on the environment or instrument panel. With the eyes downward, the pilot senses that the nose of the aircraft is rising. Common when encountering updrafts.

Answer 65

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Question 66

Oculoagravic Illusion- Results from the downward motion of the aircraft. Because of inertia the pilot’s eyes will track upward. This usually results in a sensation that the aircraft is in a nose-low attitude. This illusion is commonly encountered during autorotation.

Answer 66

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Question 67

PROPRIOCEPTIVE SYSTEM (FM 3.04.301 pg 9-8)- The systems reacts to the sensation resulting from pressures on joints, muscles, & skin & from slight changes in the position of internal organs. Forces act upon the seated pilot in flight.

Answer 67

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Question 68

Proprioceptive Illusions (FM 3-04.301 pg 9-18) These illusions rarely occur alone. They are closely associated with the vestibular system and to a lesser degree, with the visual system. During turns, banks, climbs and descending maneuvers, proprioceptive information is fed into the central nervous system. A properly executed turn vectors gravity and centrifugal force through the vertical axis of the aircraft. Without visual reference, the body only senses being pressed firmly into the seat. Because this sensation is normally associated with climbs, the pilot may falsely interpret it as such. Recovering from turns lightens pressure on the seat and creates an illusion of descending. This false perception of descent may cause the pilot to pull back on the stick, which would reduce airspeed.

Answer 68

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Question 69

Prevention of Spatial Disorientation

Answer 69

-Never fly without visual reference points. -Trust your instruments. -Avoid fatigue, smoking, hyperglycemia, hypoxia and anxiety. -Never try to fly VMC and IMC at the same time.

Question 70

Treatment of spatial disorientation

Answer 70

• Refer to the instruments and develop a good cross check. • Delay intuitive actions long enough to check both visual references and instruments. • Transfer control to the other pilot. Rarely will both experience disorientation at the same time.

Question 71

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) “BM”?

Answer 71

“Binocular Cues” “Monocular Cues”

Question 72

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) “GRAM”?

Answer 72

“Geometric perspective” “Retinal image size” “Aerial perspective” “Motion parallax”

Question 73

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Geometric Perspective cues are

Answer 73

(LAV) “Linear perspective” “Apparent foreshortening” “Vertical position in the field”

Question 74

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Geometric perspective (LAV)-An object may appear

Answer 74

to have a different shape when viewed at varying distances and from different angles.

Question 75

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Linear perspective- (explain)

Answer 75

Parallel lines, such as railroad tracks, appear to converge as distance from the observer increases.

Question 76

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Apparent foreshortening- (explain)

Answer 76

The true shape of an object or terrain feature appears elliptical (oval and narrowed appearance) when viewed from a distance. As the distance to the object or terrain feature decreases, the apparent perspective changes to its true shape or form.

Question 77

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Vertical position in the field- (explain)

Answer 77

Objects or terrain features farther away from the observer appear higher on the horizon than those closer to the observer.

Question 78

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Retinal image size cues are

Answer 78

(KITO) “Known size of objects” “Increasing or decreasing size of objects” “Terrestrial associations” “Overlapping contours”

Question 79

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Retinal image size (KITO) (explain)

Answer 79

An image focused on the retina is perceived by the brain to be of a given size.

Question 80

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 80

Known size of objects- The nearer an object is to the observer, the larger its retinal image.

Question 81

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 81

Increasing or decreasing size of objects- If the retinal image size of an object increases, the relative distance is decreasing. If the image size decreases, the relative distance is increasing. If the image size is constant, the object is at a fixed relative distance.

Question 82

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 82

Terrestrial associations- objects ordinarily associated together are judged to be at about the same distance. For example, a helicopter that is observed near an airport is judged to be in the traffic pattern and, therefore, at about the same distance as the airfield.

Question 83

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 83

Overlapping contours- When objects overlap, the overlapped object is farther away.

Question 84

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Aerial perspective (explain)

Answer 84

The clarity of an object and the shadow cast by it are perceived by the brain and are cues for estimating distance.

Question 85

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) Aerial perspective cues are

Answer 85

(FLP) “Fading of Colors or Shades” “Loss of detail of texture” “Position of light source and direction shadows”

Question 86

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 86

Fading of Colors or Shades-. Objects viewed through haze, fog, or smoke are seen less distinctly and appear to be at a greater distance than they actually are. If atmospheric transmission of light is unrestricted, an object is seen more distinctly and appears to be closer than it actually is.

Question 87

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 87

Loss of detail or texture- As a person gets farther from an object, discrete details become less apparent.

Question 88

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM)

Answer 88

Position of light source and direction shadows- Every object will cast a shadow from a light source. The direction in which the shadow is cast depends on the position of the light source. If the shadow of an object is toward the observer, the object is closer than the light source is to the observer.

Question 89

DISTANCE ESTIMATION AND DEPTH PERCEPTION (BM GRAM) “M” in GRAM is? Define.

Answer 89

Motion parallax- This is often considered the most important cue to depth perception. Motion parallax refers to the apparent, relative motion of stationary objects as viewed by an observer who is moving across the landscape. Near objects appear to move past or opposite the path of motion; far objects seem to move in the direction of motion or remain fixed. The rate of apparent movement depends on the distance that the observer is from the objects. Objects near the aircraft appear to move rapidly, while distant objects appear to be almost stationary.

Question 90

Light thru the ANVIS

Answer 90

(1) objective lens (2) photocathode (3) MCP (4) phosphor screen (5) fiber optic inverter (6) eyepiece lens Note: minus blue filter before the objective lens

Question 91

ABC vs BSP Which is for the user, which is for the ANVIS?

Answer 91

(1) Automatic Brightness Control - protects the user. (2) Bright Source Protection - protects the ANVIS.

Question 92

Explain ABC

Answer 92

The power supply provides automatic brightness control (ABC) that automatically adjusts MCP voltage to maintain image brightness at preset levels by controlling the number of electrons that exit the MCP.

Question 93

Explain BSP

Answer 93

Another feature is bright source protection (BSP) which reduces the voltage to the photocathode when exposed to bright light sources. This feature protects the I2 from damage and enhances its life; however, it lowers resolution. Exposure to bright light sources could result in damage to the photocathode, MCP, or the operator’s eye.

Question 94

What does the objective lens do?

Answer 94

Light energy, consisting of photons, enters the objective lens, is inverted and focused onto a photocathode that is receptive to both visible and near IR radiation.

Question 95

photocathode that is receptive to both visible and near IR radiation. Photons striking the photocathode are then converted to a proportionate number of electrons. Electrons are accelerated away from the photocathode to the microchannel plate (MCP) 1

Answer 95

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Question 96

microchannel plate (MCP) via an electrical field produced by the power supply. The MCP is a thin wafer of tiny glass tubes that are tilted about 8 degrees. Electrons enter these tubes and strike the walls, creating a reaction which exponentially increases the amount of electrons. These increased numbers of electrons are then accelerated to the phosphor screen.

Answer 96

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Question 97

The phosphor screen emits an amount of photons proportional to the number and velocity of the electrons striking it creating a lighted image.

Answer 97

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Question 98

The image is then passed through a fiber- optic inverter to rotate the image 180 degrees to correct the inverted image caused by the objective lens.

Answer 98

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Question 99

The image is then focused onto the viewer’s eye through an eyepiece lens.

Answer 99

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Question 100

OPERATIONAL DEFECTS (AN/AVS-6/-10) - If identified, they are…

Answer 100

an immediate cause for reject.

Question 101

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) What is SEEFFI?

Answer 101

(1) Shading (2) Edge Glow (3) Emmision Points (4) Flickering (5) Flashing (6) Intermittent Operation

Question 102

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Shading

Answer 102

SHADING - You will not see a fully circular image. Shading always begins on the edge and moves inward.

Question 103

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Edge Glow

Answer 103

EDGE GLOW - A bright area in the outer portion of the viewing area. To check for this defect, block out all light by cupping your hand over the lens.

Question 104

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Emission Points

Answer 104

EMISSION POINTS - A steady or fluctuating pinpoint of bright light in the image area and does not go away when all light is blocked from the objective lens of that monocular.

Question 105

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Flickering, Flashing, Intermittent Operation

Answer 105

FLICKERING, FLASHING, INTERMITTENT OPERATION - the NVG may appear to flicker on and off, or the output may flash. This can occur in one or both tubes. If you see more than one flicker, consult the troubleshooting chart in the operator’s manual.

Question 106

COSMETIC BLEMISHES (AN/AVS-6/-10) - These are usually the…

Answer 106

result of manufacturing imperfections that do not affect image intensifier reliability and are not normally a cause for rejection unless they interfere with the ability to perform the mission.

Question 107

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) The acronym BBIFCO stands for?

Answer 107

(1) Bright Spots (2) Black Spots (3) Image Disparity (4) Chicken Wire (5) Fixed-Pattern Noise (6) Output Brightness Variation

Question 108

OPERATIONAL DEFECTS (AN/AVS-6/-10) - If identified, they are…

Answer 108

an immediate cause for reject.

Question 109

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) What is SEEFFI?

Answer 109

(1) Shading (2) Edge Glow (3) Emmision Points (4) Flickering (5) Flashing (6) Intermittent Operation

Question 110

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Shading

Answer 110

SHADING - You will not see a fully circular image. Shading always begins on the edge and moves inward.

Question 111

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Edge Glow

Answer 111

EDGE GLOW - A bright area in the outer portion of the viewing area. To check for this defect, block out all light by cupping your hand over the lens.

Question 112

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Emission Points

Answer 112

EMISSION POINTS - A steady or fluctuating pinpoint of bright light in the image area and does not go away when all light is blocked from the objective lens of that monocular.

Question 113

OPERATIONAL DEFECTS (SEEFFI) (AN/AVS-6/-10) Define Flickering, Flashing, Intermittent Operation

Answer 113

FLICKERING, FLASHING, INTERMITTENT OPERATION - the NVG may appear to flicker on and off, or the output may flash. This can occur in one or both tubes. If you see more than one flicker, consult the troubleshooting chart in the operator’s manual.

Question 114

COSMETIC BLEMISHES (AN/AVS-6/-10) - These are usually the…

Answer 114

result of manufacturing imperfections that do not affect image intensifier reliability and are not normally a cause for rejection unless they interfere with the ability to perform the mission.

Question 115

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) The acronym BBIFCO stands for?

Answer 115

(1) Bright Spots (2) Black Spots (3) Image Disparity (4) Chicken Wire (5) Fixed-Pattern Noise (6) Output Brightness Variation

Question 116

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Bright Spots

Answer 116

BRIGHT SPOTS - These are signal induced. A bright spot is a small, bright area that may flicker or remain constant.

Question 116

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Bright Spots

Answer 116

BRIGHT SPOTS - These are signal induced. A bright spot is a small, bright area that may flicker or remain constant.

Question 117

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Black Spots

Answer 117

BLACK SPOTS - These are blemishes in the image intensifier or dirt or debris between the lenses.

Question 117

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Black Spots

Answer 117

BLACK SPOTS - These are blemishes in the image intensifier or dirt or debris between the lenses.

Question 118

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Image Disparity

Answer 118

IMAGE DISPARITY - This condition exists when there is a difference in brightness between the two image intensifier assemblies within the same binocular.

Question 118

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Image Disparity

Answer 118

IMAGE DISPARITY - This condition exists when there is a difference in brightness between the two image intensifier assemblies within the same binocular.

Question 119

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Chicken Wire

Answer 119

CHICKEN WIRE - An irregular pattern of dark thin lines in the field of view either throughout the image or in parts of the image. Under worst conditions, these lines will form hexagonal shaped lines.

Question 119

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Chicken Wire

Answer 119

CHICKEN WIRE - An irregular pattern of dark thin lines in the field of view either throughout the image or in parts of the image. Under worst conditions, these lines will form hexagonal shaped lines.

Question 120

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Fixed-Pattern Noise (Honeycomb)

Answer 120

FIXED-PATTERERN NOISE (HONEYCOMB) - Characterized by faint hexagonal pattern throughout the viewing area that most often occurs at highlight levels.

Question 120

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Fixed-Pattern Noise (Honeycomb)

Answer 120

FIXED-PATTERERN NOISE (HONEYCOMB) - Characterized by faint hexagonal pattern throughout the viewing area that most often occurs at highlight levels.

Question 121

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Output Brightness Variation

Answer 121

OUTPUT BRIGHTNESS VARITION - This condition is evidenced by areas of varying brightness in or across the image area. Do not confuse with shading.

Question 121

COSMETIC BLEMISHES (BBICFO) (AN/AVS-6/-10) Define Output Brightness Variation

Answer 121

OUTPUT BRIGHTNESS VARITION - This condition is evidenced by areas of varying brightness in or across the image area. Do not confuse with shading.