Exam 2 Flashcards
What senses does the brain use to determine orientation?
- Vision (90%)
- Proprioception (Body Sense of motion)
- Vestibular Senses (Linear/Angular Acceleration)
What organs does the Vestibular System use to determine our position and motion?
- Otoliths - detect LINEAR acceleration
2. Semicircular Canals - detect ANGULAR (rotation) acceleration
What is one common example of how the forces of flight can cause the vestibular system to provide misleading info about orientation
- When the liquid in the ears and the body are moving the same speed, and motion is no longer detected (takes about 20 seconds to equilibrate)
Describe the mechanism for the undetected motion illusion
- Any angular acceleration that is less than 3 degrees per second
- Not detected w/o visual reference
Describe the strengths and challenges related to central (foveal) vision
- Fovea, high concentration of receptors (CONES)
- Acuity and Color (can influence depth preception)
- Rapid focus capability, but sharp focus requires delays
Describe the proper scanning technique to avoid relative motion and night vision blind spots
- Off center scan due to a central blind spot
What are the mechanics of Autokinesis?
- When the eye moves to try and get a better perception of a light, and it appears to be moving when really its just your eye
What is a common illusion seen with sloping cloud decks, ground reference lights, and distant cues?
False Horizons
Gravic refers to:
A linear/straight line motion
Gyric refers to:
A turning motion
Describe the strengths and challenges related to PERIPHERAL vision
- Rods
- Best for NIGHT vision
- Orientation
- Field Flow (Your velocity/speed)
- Motion of objects in your field of vision
What sense is responsible for giving you the feeling of sinking back into your seat during an acceleration?
Proprioception (body sense)
Vestibulo refers to:
The vestibular system (Otoliths and SCCs)
Oculo/Ocular refers to:
The Eyes
Somato refers to:
The body
What is the leading cause of CFIT accidents?
Spatial disorientation!!!
What accounts for 70% of approach/landing accidents?
Low visibility and precipitation
What are the FUNCTIONS of the vestibular system?
- Maintain orientation
- Assist with balance/movement
- Coordinate eye movement (Vestibulo-ocular reflex)
What kind of motion do the Otoliths detect?
- Linear acceleration (forward and vertical acceleration)
What kind of motion do the Semicircular Canals detect?
- Rotation (constant speed turns, spins)
Where is your blind spot at night?
Central to both eyes
What does an effective scanning technique involve?
- Focus in blocks, stopping for 1-2 seconds
- 60 degrees L/R
- 10 degrees up/down
Why do most mid-air collisions occur between a/c flying in the SAME (parallel) direction?
- Due to the lack of relative motion (movement of 1 object in relation to another moving object)
What types of monocular cues do humans use to aid in depth and distance perception?
- Occlusion/Overlay
- Size Reference/Constancy
- Air clarity/Haze
- Contrast/Texture of surface
Describe the Oculogyric Illusion
- Vestibulo-ocular reflex allows the eye to track while the body is in motion
- When we stop spinning with minimal visual cues, objects appear to move with us
Describe the SomatoGYRIC Illusion
- When in a steady state turn for over 20 seconds and the turn is no longer sensed
- Leaving the turn gives the false sensation that you are turning the opposite way
Describe a Graveyard SPIN and when it’s most likely to occur
- When a spin w/o visual reference goes undetected after 20 seconds (stopping the spin creates the illusion of turning in the opposite direction)
- Occurs after spin RECOVERY
Describe a Graveyard SPIRAL and when it’s most likely to occur
- When a spiral w/o visual reference goes undetected after 20 seconds (stopping the spiral creates the illusion of turning in the opposite direction)
- Occurs after stopping a spiraling turn
- FORCES ARE GREATER than in a spin
Describe the Coriolis Illusion
- Acceleration in a turn is detected in 1 SCC
- Movement of the HEAD on a different plane sets off detection in another SCC
Describe the Somatogravic Illusion
- Forward thrust/acceleration is interpreted as sudden pitch up
- Leading cause of CFIT accidents
Describe the Inversion Illusion
- When you level off after a climb and the hair cells move toward the top of the head
- Gives the sensation of flying inverted when no visual cues are present
Describe a G-Excess Effect and when it would occur
- Gives the illusion that you are in a bank angle that is too shallow (leading to you increasing the bank angle)
- Occurs when you look to the “inside” of an increased G turn
Describe the Elevator Illusion and when it would occur
- When your eyes roll up/down with turbulence giving the false impression of being nose high/nose low
- When flying through updrafts and downdrafts
Describe the Leans
- When you roll into a turn too slowly and it goes undetected, the. When you go to roll out you ears suddenly pick the movement up and want you to correct back into the turn
- A consequence of undetected motion
What are the 3 types of Spatial Disorientation?
1 - Unrecognizable
2 - Recognizable
3 - Incapacitating
How can you combat Spatial Disorientation (SDO)
- Vigilance/Increased Awareness
- TRUST YOUR INSTRUMENTS
- Maintain straight and level for 30-40 seconds to correct symptoms
What type of Illusion can you expect to see from a narrow runway?
- You think you’re HIGHER than you really are, causing you to fly a lower than normal approach and land short
What type of Illusion can you expect to see from a wide runway?
You think you’re LOWER than you really are, causing you to fly a higher than normal approach and land long
What type of Illusion can you expect to see from an upward sloping runway?
- You think you’re HIGHER than you really are, causing you to fly a lower than normal approach and land short
What type of Illusion can you expect to see from a downward sloping runway?
You think you’re LOWER than you really are, causing you to fly a higher than normal approach and land long
What are the 2 different TYPES of pressurization systems?
- Sealed Cabins
2. Pressure Cabins
What are some DIS-ADVANTAGES of pressurization systems?
- Expensive, heavy
- Possible contamination of air
- Risk of inadvertant loss of cabin pressure
What factors control the rate of decompression?
- Cabin Volume (large cabin = slower decompression)
- Size of Opening (smaller opening = slower decompression)
- Pressure Differential/Ratio between cabin and ambient pressure (the higher the pressurization ratio, the slower the decompression)
What are the physical/physiological effects of a rapid decompression?
Physiological: Hypoxia and Evolved gas sickness (DCS)
Physical: Temperature drop, debris, windblast, fogging, loud noise
What is the emergency procedure following a rapid decompression?
- Don O2 mask at 100%
- Descend (-600fpm or less)
- Structural integrity
- Don thermal protection
- Get to a safe altitude
- Check passengers