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H-60A/L Blackhawk > NVG > Flashcards

Flashcards in NVG Deck (35)
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1
Q

What are the three types of vision? When is each used?

A
  • Photopic - full daylight
  • Mesopic - dawn/dusk
  • Scotopic - night
2
Q

What type of vision is used when wearing NVGs?

A

Photopic

3
Q

What is off-center viewing/vision?

A

Looking 10 degrees above, below, or to the side of an object to compensate for night blind spot

4
Q

Monocular cues are used for ___ and remembered with the acronym ___?

A
  • Depth perception and distance estimation

“GRAM”

5
Q

Describe the geometric monocular cues; and are remembered with what acronym?

A

“LAV”

  • Linear perspective (converging lines - railroad tracks)
  • Apparent foreshadowing (objects appear elliptical when viewed at distance, and appear normal when approaching)
  • Vertical Position (objects at distance appear higher on the horizon)
6
Q

Describe the retinal image size monocular cues; and are remembered with what acronym?

A

“KITO”

  • Known size (closer objects appear larger)
  • Increasing size (object increase in size as they get closer)
  • Terrestrial association (objects associated with each other are judged to be at the same distance)
  • Overlapping contours (when objects overlap, the hidden object is farther away)
7
Q

Describe the aerial perspective monocular cues; and are remembered with what acronym?

A

“FLP”

  • Fading color/shades (objects appear farther than actual when viewed through fog/haze, and closer than actual when viewed through clear sky)
  • Loss of detail (as objects get farther away, detail is reduced)
  • Position of light, shadows (shadows are cast away from a light source)
8
Q

Describe motion parallax.

A

“Most important” monocular cue for objects on left/right - close stationary objects appear to move in fast and in opposite direction of travel; far stationary objects appear to move slowly in same direction of travel

9
Q

The moon angle changes at what rate per hour?

A

13.2 degrees, approximately equal to it’s apparent size

10
Q

What is the field of vision of the ANVIS-6?

A

40 degrees

11
Q

Normal night visual acuity is approximately ___. NVGs enhance this to about ___. The best possible visual acuity at night is ___.

A
  • 20/200
  • 20/70
  • 20/25 (if 100% illum, clear weather, low humidity)
12
Q

What is the focal range of the ANVIS-6?

A

11” to 50m (“optical infinity”)

13
Q

The ANVIS-6 amplifies light by ___.

A

2000-3000x

14
Q

The battery low voltage indicator flashes ___ when the batteries fall below ___?

A
  • red
  • 2.4V
15
Q

Why should rechargeable (NiCd) batteries not be used?

A

Combined voltage of 2 AA batteries is only 2.4V, and would trigger the low-voltage indicator with new batteries

16
Q

What are the 4 operational defects? What acronym is used to remember them?

A

“FEES”

  • Flickering
  • Emission point
  • Edge glow
  • Shading
  • Laser Damage (not a conventional defect but should not use if seen)
17
Q

What is the magnification of the ANVIS-6?

A

1x - NVGs amplify light, do not magnify

18
Q

If needed, how are the electrical contacts cleaned?

A

Pencil eraser

19
Q

When the low voltage indicator starts flashing, you have approx how much battery life remaining?

A

30 minutes

20
Q

What acronym is used to remember the visual illusions?

A

FFF CRASH CSAR

21
Q

What visual illusions are represented by FFF?

A
  • Flicker Vertigo – rotors interrupting sunlight, strobe lights (especially in clouds); creates flashing effect, generally annoying but may induce seizures between 4-20 Hz. Turn off light source if possible
  • Fixation – Task or target; do not focus on an object/task for too long and forget to scan effectively
  • False Horizon – Confusing clouds/snowbanks with horizon, causes false sense of orientation
22
Q

What visual illusions are represented by CRASH?

A
  • Confusing Ground Lights – mistaking ground lights for stars, causing false sense of orientation. Maintain proper scan.
  • Relative Motion – Perceive self in motion due to movement of another object. Maintain scan, be aware of problem.
  • Altered Plane of Reference – Inaccurate sense of altitude, attitude, or flight path due to very large object (mountain), will maneuver to avoid object though not required. Perform map recon and search for true horizon.
  • Structural Illusions – Caused by heat, rain, or snow; straight lines appeared curved when viewed through heat isotherms, ice or rain on windshield. Be aware of conditions and problem.
  • Height/Depth Perception – Loss of depth perception due to insufficient visual cues. Trust instruments and scan horizon.
23
Q

What visual illusions are represented by CSAR?

A
  • Crater Illusion – When landing under NVGs with searchlight, shadow may cause illusion of landing surrounded by upslopeing terrain. Use search/landing light appropriately, be aware of problem.
  • Size-Distance Illusion – False perception of distance from an object of unfamiliar size (smaller or larger runway/trees/buildings/aircraft than used to). Be aware of problem, use experience.
  • Autokinesis – Occurs when few visual cues are available, an object appears to move when fixated on for more than 5-6 seconds. Avoid fixation and maintain proper scan.
  • Reversible Perspective – Silhouette of an object appears same from front or back, unable to tell if object is moving toward or away from viewer. Maintain proper scan, remember 3 Rs (Red on Right is Returning)
24
Q

What are the three types of spatial disorientation?

A
  • Unrecognized (Type 1) – Aviator is disoriented but does not believe anything is wrong. Most dangerous type.
  • Recognized (Type 2) – Aviator perceives a problem but may not recognized it as spatial disorientation.
  • Incapacitating (Type 3) – Aviator cannot orient to visual cues or instruments due to severity of disorientation. Co-pilot/CE should recognize, announce, and/or take control of aircraft.
25
Q

What exterior lights must be operational before an NVG flight?

A

Cargo hook well area electroluminescent lighting, IR formation and position lights

26
Q

What are the 7 most common cosmetic blemishes?

A

Bright spots, black spots, chicken wire, fixed-pattern noise, image disparity, output brightness variation, distortion

27
Q

How should the battery pack be oriented on the flight helmet? Where is the primary and alternate battery when oriented properly?

A
  • Oriented with switch/cable up.
  • Primary battery on right, alternate battery on left.
28
Q

What is the ABC, what part of the NVG does it effect, and what does it do?

A
  • Automatic Brightness Control - reduces voltage to microchannel plate under high-light conditions to reduce image brightness, so that night vision is not affected
29
Q

What is the BSP, what part of the NVG does it effect, and what does it do?

A
  • Bright-source Protection - reduces voltage to the photocathode under high light conditions (tracers, explosions) to prevent damage to the MCP
30
Q

What part of the ANVIS-6 filters blue light?

A

A coating on the objective lens - filters blue light so that blue interior/instrument lights do not cause glare

31
Q

Night vision adaptation takes approximately how long in optimal conditions?

A

30-45 minutes

32
Q

What are the 5 deadly self-imposed stressors

A

“DEATH”

Drugs, Exhaustion, Alcohol, Tobacco, Hypoglycemia

33
Q

What are the 4 types of hypoxia?

A

Hypoxic, Hypemic, Histotoxic, Stagnant

34
Q

What are the major components of the ANVIS-6? What does each do? What mnemonic is used to remember them?

A

“Other people’s money pays for everything” - Objective - inverts image, filters blue light - Photocathode - converts photons to electrons (1:1) - Microchannel Plate - multiplies number of electrons - Phosphorescent Screen - creates visible (green) image from electrons - Fiberoptic Inverter - inverts image to proper orientation - Eyepiece - view image, artificial focal depth of 6 feet

35
Q

What is scintillation? When is it seen?

A
  • Snowy/static pattern (like an old tv)
  • Seen in low illumination (<25%); can be a sign of worsening weather