APART Study Guide

Question 1

NVG NOMENCLATURE, CHARACTERISTICS, LIMITATIONS, AND OPERATIONS

Describe how light passes through the ANVIS.

Answer 1

OPMPFE
* Objective Lens (inverts image, minus blue filter)
* Photocathode (changes photons to electrons)
* Microchannel Plate (multiplies electrons)
* Phospher Screen (electrons to protons, creates the lighted image)
* Fiber Optic Inverter (inverts the image)
* Eyepiece Lens (allows the eye to see the image)

Question 2

What is Automatic Brightness Protection (ABC)?

Answer 2

ABC automatically adjusts microchannel plate (MCP) voltage to maintain image brightness at preset levels by controlling the amount of electrons that exit the MCP.

ABC is to protect the wearers vision, not to protect the goggles.

Question 3

What is Bright Source Protection (BSP)?

Answer 3

Reduces the voltage to the photocathode when exposed to bright light sources.

This protects the goggles 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 4

What are the ANVIS operational defects?

Answer 4

SEEF
Flashing, Flickering, or Intermittent Operation
Edge Glow
Shading
Emission Point

Question 5

ANVIS OPERATIONAL DEFECT

Describe Flashing, Flickering or Intermittent Operation.

Answer 5

Light appears to flicker or flash. Can be in either one or both monoculars.

Question 6

ANVIS OPERATIONAL DEFECT

Describe Edge Glow

Answer 6

A bright area in the outer portion of the viewing area (could be caused by a series of emission points).

Check by covering the light entering from the objective lens. If it remains, it is edge glow.

Question 7

ANVIS OPERATIONAL DEFECTS

Describe Shading

Answer 7

You will not see a fully circular image, regardless of the adjustment. Begins at the edge and works inward. There will be a high contract area with a distinct line of demarcation.

Question 8

ANVIS OPERATIONAL DEFECTS

Describe an Emission Point

Answer 8

A steady or fluctuating pinpoint of bright light in the image area and does not go away when all light is
blocked from the OBJ lens.

Question 9

What are the ANVIS cosmetic blemishes

Answer 9

IF I COB
Image Distortion
Fixed Pattern Noise
Image Disparity
Chicken Wire
Bright Spots
Output Brightness Variation
Black Spots

Question 10

ANVIS COSMETIC BLEMISHES

Describe Image Distortion

Answer 10

Evidenced by vertical objects (poles / trees) appearing to bend when you move your head vertically or
horizontally.

Ground surfaces may appear to swell or sink as well.

Question 11

ANVIS COSMETIC BLEMISHES

Explain Fixed Pattern Noise

Answer 11

AKA Honeycomb

Faint hexagonal pattern throughout the viewing area that most often occurs at highlight levels.

Question 12

ANVIS COSMETIC BLEMISHES

Explain Image Disparity

Answer 12

Difference in brightness between the two image intensifier assemblies within the same binocular.

Question 13

ANVIS COSMETIC BLEMISHES

Explain Chicken Wire

Answer 13

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 (think of it as the beginning of
honeycomb)

Question 14

ANVIS COSMETIC BLEMISHES

Explain Bright Spots

Answer 14

These are SIGNAL induced - a bright spot is a small bright area that may flicker or remain constant.

Question 14

ANVIS COSMETIC BLEMISHES

Explain Output Brightness Variation

Answer 14

Evidenced by Areas of varying brightness in or across the image area.

DO NOT CONFUSE WITH SHADING. There are no distinct lines of demarcation

Question 15

ANVIS COSMETIC BLEMISHES

Explain Black Spots

Answer 15

These are blemishes in the image intensifier or dirt, hair or debris between the lenses.

Question 16

What is the intensification of the ANVIS?

Answer 16

2000-3000 times

Question 17

What is the visual acuity of the ANVIS

Answer 17

Best is 20/25 when looking through the center of the tubes. At the periphery, the acuity can decrease to 20/70

Question 18

What is the FOV of the ANVIS with proper OSAP?

Answer 18

40 degrees

Question 19

What is rhe Breakaway force of the ANVIS?

Answer 19

10-15Gs

Question 20

What are some limitations of the ANVIS?

Answer 20

Reduction in visual acuity
Color vision decrease/dissapear
Night blind spot

Question 21

What are the three night vision techniques that can help overcome ANVIS limitations?

Answer 21

SOS

Scanning
Off center viewing
Shapes or Silhouettes

Question 22

What are the Visual Illusions?

Answer 22

FFSHAVSCC (For Fucks Sake HAVe Some Class Carl)

Fascination/Fixation
False Horizon
Size/Distance Illusion
Height/Depth Perception Illusion
Autokinesis
Vection (Inducted Motion Illusion)
Structural Illusion
Confusion with

Question 23

VISUAL ILLUSION

Describe Facination/Fixation

Answer 23

**Fascination: **Task Saturation (in cockpit) - so engrossed with a problem or task within the cockpit, they fail to scan outside

Fixation: Target Fixation (out of cockpit) - fixating on object outside the cockpit you fail to scan/crosscheck

Solution: refrain from staring; scan

Question 24

# VISUAL ILLUSION Describe False Horizon

Answer 24

Aviator confuses cloud formations with the horizon or the ground, thus they may fly the aircraft in a banked attitude. **Solution**: Scan instruments and other visual cues

Question 25

# VISUAL ILLUSION Describe Size Distance Illusion

Answer 25

1. Size Constancy Illusion – an example is landing at an unfamiliar runway. A narrower runway may lead a pilot to believe he/she is higher and further away. 2. Shape Constancy Illusion – Commonly encountered with sloping runways. An upsloping runway may give the pilot the illusion of being too high 3. Aerial Perspective Illusion – visual cues are of a different size or perspicuity (clarity and discrimination) than expected. An example is mistaking short immature trees for full grown ones. Also, objects within a hazy environment are often thought to be further away than they actual area.

Question 26

# VISUAL ILLUSION Describe Height/Depth Preception Illusion

Answer 26

The height - depth perception illusion is due to a lack of sufficient visual cues and causes an aircrew to lose depth perception (i.e. flying over desert, snow, water the aviator may fly extremely low due to lack of cues.) **Solution:** trust instruments and scan horizon

Question 27

# VISUAL ILLUSION Describe Autokinesis

Answer 27

Primarily occurs at night when ambient visual cues are minimal and a small dim light is seen against a dark background. Aviator visually fixates on light for 6-12 seconds, the light appears to move up to 20 degrees in any direction and continues to "move". **Solution:** avoid fixating on objects, develop a good scan.

Question 28

# VISUAL ILLUSION Describe Vection

Answer 28

Falsely perceived self-motion (at a stop light, car next to you starts moving and you think you’re moving). **Solution: **proper scanning - experience / knowledge of the occurrence

Question 29

# VISUAL ILLUSION Describe the Structural Illusion

Answer 29

Caused by effects of heat waves, rain, snow, sleet, or the shape of the windscreen - objects may appear obscure / not their true shape/size. **Solution:** experience / knowledge.

Question 30

# VISUAL ILLUSION Describe Confusion with Ground Lights

Answer 30

Aviator mistakes ground lights for stars - which prompts aviator to place the aircraft in an unusual attitude to keep the misperceived ground lights above them. **Solution:** conduct a proper scan, aided and unaided.

Question 31

# VISUAL ILLUSION Describe the Crater Illusion

Answer 31

Aviator mistakes ground lights for stars - which prompts aviator to place the aircraft in an unusual attitude to keep the misperceived ground lights above them. **Solution:** conduct a proper scan, aided and unaided.

Question 32

What are the 5 major components of the eye?

Answer 32

1. Cornea 2. Iris 3. Pupil 4. Lens 5. Retina

Question 33

What are the 3 types of vision?

Answer 33

*PMS* **P**hotopic - day OR bright/high light levels **M**esopic - dusk/dawn OR medium to low level light **S**cotopic - night OR low light levels

Question 34

What are the Monocular Cues?

Answer 34

*GRAM* **G**eometric Perspective **R**etinal Image Size **A**erial Prespective **M**otion Parallax

Question 35

# MONOCULAR CUES What is Geometric Perspective and what cues does it include?

Answer 35

An object may appear to have a different shape when viewed at varying distances and from different angles. *LAV* **L**inear Perspective **A**pparent Foreshortening **V**ertical Position in Field

Question 36

# MONOCULAR CUES Explain Linear Perspective

Answer 36

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

Question 37

# MONOCULAR CUES Explain Apparent Foreshortening

Answer 37

The true shape of an object or terrain feature appears elliptical (oval and narrowed appearance) when viewed from a distance.

Question 38

# MONOCULAR CUES Explain Vertical Position in Field

Answer 38

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

Question 39

# MONOCULAR CUES What is Retinal Image Size and what cues does it include?

Answer 39

An image focused on the retina is perceived by the brain to be of a given size. *KITO* **K**nown Size of Objects **I**ncreasing/Decreasing Size of Objects **T**errestrial Association **O**verlapping Contours

Question 40

# MONOCULAR CUES Explain Known Size of Objects

Answer 40

Familiarity with an object or classification of objects allows us to determine the relative distance to that object. The nearer an object is to the observer, the larger its retinal image.

Question 41

# MONOCULAR CUES Explain Increasing/Decreasing Size of Objects

Answer 41

If size is increasing, object is coming closer - if size is decreasing the object is moving farther away - if size is constant, object is staying the same distance.

Question 42

# MONOCULAR CUES Explain Terrestrial Association

Answer 42

Objects normally associated together (helicopter and heliport / airport) are judged to be at about the same distance and assist in determine size.

Question 43

# MONOCULAR CUES Explain Overlapping Contours

Answer 43

When objects overlap, the overlapped object is farther away.

Question 44

# MONOCULAR CUES What is Aerial Perspective and what cues does it include?

Answer 44

The clarity of an object and the shadow cast by it are perceived by the brain and are cues for estimating distance. *FLP* **F**ading of Colors and Shades **L**oss of Detail or Texture **P**osition of Light Source and Direction of Shadows

Question 45

# MONOCULAR CUES Explain Fading of Colors and Shades

Answer 45

Objects viewed through haze, fog or smoke are seen less distinctly and appear to be at a greater distance than they actually are. If light is unrestricted - the opposite is true because you can see the object more distinctly / more details - so it appears closer.

Question 46

# MONOCULAR CUES Explain Loss of Detail or Texture

Answer 46

As a person gets farther from an object, discrete details become less apparent (a corn field from high altitude looks like a green blob and everything seems to blur together - but up close, you can tell it is clearly a corn field with distinct rows and patterns).

Question 47

# MONOCULAR CUES Explain Position of Light Source and Direction of Shaddows

Answer 47

Every object casts 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 towards the observer, the object is closer than the light source is to the observer.

Question 48

# MONOCULAR CUES Describe Motion Parallax

Answer 48

(Most Important for depth perception) - Apparent relative motion of stationary objects as viewed by an observer who is moving across the landscape Near objects appear to move against the direction of travel Far objects appear to move with the direction of travel slightly, or stay stationary.

Question 49

What benefit does pre-breathing oxygen / having oxygen available have yon your night vision?

Answer 49

You start to lose night vision at 4,000 feet PA because of lack of oxygen to the RODS. Lack of oxygen to the rods significantly reduces their sensitivity, increasing the time required for dark adaptation and decreasing their ability to see at night. RHODOPSIN IS OXYGEN DEPENDENT.

Question 50

Describe the Night Blind Spot

Answer 50

Occurs when the fovea becomes inactive under darkness or low level illumination - central vision becomes less effective and the night blind spot develops. The night blind spot covers **5-10 degrees of central vision.** This is due to the fact that there are no rods on the fovea centralis (the center of vision).

Question 51

Describe the Day Blind Spot

Answer 51

The day (physiological) blind spot is present all the time (including at night). 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 **5.5-7.5 degrees and is located about 15 degrees from the fovea.**

Question 52

What are the 4 sections of the engine?

Answer 52

1. Hot Section 2. Cold Section 3. Power Turbine Section 4. Accessory (Gearbox) Section

Question 53

What sensors are located on the aft top portion of the left and right sides of the engine?

Answer 53

Left - Np Sensor Right - Torque and Overspeed Sensor

Question 54

What are the functions of the HMU?

Answer 54

**P**umps fuel at high pressure **M**eters fuel via LDS, PAS and DEC (torque motor) **C**ollective pitch compensation through LDS **A**ccel/Decel fuel flow to prevent compressor stall **N**g Limiting **V**ariable guide veins for optimal performance **D**EC lockut via PAS (bypass torque motor from the DEC) **T**orque motor trims Ng **O**pens vapor vent for fuel priming | PM CAN VDTO