AeroPhys Overview 27-03

Human factors

optimizes relationship between people and their activities

Gas composition of the atmosphere

78% Nitrogen, 21% oxygen, and 1% carbon dioxide and other gases

US Standard atmospheric unit

760 mmHg

At what altitude does 11-202 vol3 say you need supplemental oxygen?

10,000 feet, the end of the physiological deficient zone

At what altitude do physiological symptoms occur?

any altitude

Signs of hypoxia

Working harder to breathe, increased rate and depth of breathing, cyanosis

Pressure breathing requires...

active exhale and passive inhale (opposite of normal)

Causes of hyperventilation

Lack of oxygen (hypoxic hypoxia), improper pressure breathing, stress

All symptoms in the air...

Should be treated the same! Don't delay treatment trying to find the cause!

Most effective way to equalize pressure...

Valsalva maneuver

Type of DCS where a rash is experienced

Skin manifestations aka "creeps"

Type of DCS where in hurts to bend your joints

Musculoskeletal manifestation "the bends"

Type of DCS where you experience chest pain (sternum pain)

Respiratory manifestation "the chokes"

Type of DCS where you experience a bad headache or loss of vision

Central Nervous System (CNS) manifestation

What should you do if your passenger is experiencing the bends?

100% oxygen, land as soon as practical, mobilization, land as soon as practical

Signs of rapid decompression

Hears bang, debris, temperature drop, fog and smoke

Main reason for aircraft pressurization

reduces DCS and hypoxia

Most practical method to reduce hearing damage

Combining protective gear

How to use your ear protection?

PRESS, INSERT, ALLOW TO FULLY EXPAND

Impacts of vibration

Increased reaction time, visual impairment, fatigue, poor vertical tracking

Characteristics of Peripheral Vision

"the where", poor acuity, no color because your peripheral uses RODS

What causes your "nighttime blindspot"?

The FOVEA doesn't have any rods

What is the mechanism used to judge distances below 200 meters?

Stereopsis

When flying in the day, can you see details using your peripheral vision?

NO

Best scanning method for daytime?

Z scan, divide the sky into sectors and pause in each sector

Best scanning method for nighttime?

Use a 10-15 degree offset! retina has more rods

Autokinesis

When stationary lights appear to move, STOP staring asap.

See a laser?

LOOK AWAY and shield your eyes

Most reliable sense in aviation?

Vision

Which sensory system is describes as "seat of the pants"?

Somatosensory system

Which sensory system is unreliable in a positive G environment

Somatosensory system, due to little variation in pressure cues.

What are the two types of information processing?

Conscious and subconscious

What are the three levels of awareness?

Perception (Basic), Comprehension (Intermediate), Prediction (Advanced)

Situational Awareness depends on

Knowledge, predictive capability

Signs you've lost SA

Poor comms, task fixation, unresolved discrepancies, complacency

After recognizing loss of SA

Aviate first

Somatogyral Illusions

1. Leans (most common)

2. Graveyard Spin (more common in fixed wing)

3. Coriolis Illusion (most dangerous)

CAUSED by angular acceleration

Pitch up/pitch down illusions

Caused by rapid linear acceleration/decceleration

The chair demo with the thumbs

Is a misperception of roll/bank

Factors that cause spatial disorientation *

Weather, conflicting orientation cues, self imposed stresses such as alcohol and self medication, long missions, fatigue

To adjust to a false horizon

use cross check

To prevent spatial disorientation

"correct what you can correct", recognize high risk situations, understand limitations

How to recover from spatial disorientation

Transition to instruments, minimize head movements

What are the two components of AGSM

1. Strain 2. Breathing (which need to happen SIMULTANEOUSLY)

What is the most common cause of GLOC?

bad AGSM

What are the five factors determining the effect of G-forces?

Magnitude, duration, rate of application, direction of force (and previous G exposure)

G strain does what to mobility?

Decreases mobility, it is harder to move under G strain

Symptoms of excess G exposure

Gray out, black out, unconscious

Two phases of GLOC

absolute incapacitation and relative capacitation

Relative incapacitation

Stupor, memory loss, disoriented state that occurs AFTER gloc

AGSM breathing

Exhange air every 3 seconds, start AGSM BEFORE experiencing G forces

Factors that decrease personal G tolerance

Fatigue, dehydration, alcohol, self-medication, poor diet

Factors that improve G tolerance

Balanced physical fitness program and well rested

Hypoglycemia

Low blood sugar which can be prevented by eating regularly

Types of fatigue

Acute, cumulative, chronic

Benefits of caffeine

Elevates mood, mask feelings of fatigue, increase capacity for work

Drawbacks of caffeine

Dehydrates you, difficult to sleep, restlessness, nervousness

How to prevent heat stress

Hydration, nutrition, well rested, acclimate

Oxygen emergency bottle

green bottle, works for ten minutes

Diluter level to 100%

means you have 95% oxygen

Seal

Black

What causes chronic fatigue?

Multiple nights of bad sleep