5. Aeromedical Factors

Question 1

Physiological (self-imposed) stressors

Answer 1

• Drugs
  
  • Self medication
  • Overdose problems
  • Allergic reactions
  • Predictable side effects
  • Synergistic effects
  • Caffeine.
• Exhaustion
  
  • Lack of rest and sleep
  • Physical conditioning
• Alcohol
• Tobacco
• Hypoglycemia

Question 2

Physiological stressors - Drugs

Answer 2

• Self medication
  
  • Most drugs have unwanted side effects.
  • In general no crewmember taking medication is fit to fly unless cleared by the Flight Surgeon
• Overdose
  
  • Taking more than recommended can be dangerous
• Allergic reactions
  
  • Some people experience exagerated or pathological reactions to a given medication. Ex. penicilin
• Predictable side effects
• Synergistic effects
  
  • Undesired effects resulting from combination of drugs
• Caffeine
  
  • Caffeine might decrease performance
  • High blood pressure, impair hand-eye coordination and timing, cause nervousness.

Question 3

Hypoxia

Answer 3

Hypoxia results when the body lacks oxygen

• Hypemic
  
  • Reduction in blood`s oxygen-carrying capacity. (Blood loss or carbon monoxide)
• Stagnant
  
  • Inadequate circulation (G forces, Heart failure predispose individuals to stagnant hypoxia)
• Histotoxic
  
  • Interference with the use of oxygen by body tissue (alcohol, narcotics and cyanide poison)
• Hypoxic
  
  • Not enough oxygen in the air or when increasing atm. pressure. (Partial pressure PO2)

Question 4

Stages of Hypoxic Hypoxia

Answer 4

• Indifferent
  
  • Decreased night vision above 4000 feet
  • 0–10 K
  • 98%–90% oxygen saturation
• Compensatory
  • ​​89%–80% oxygen saturation
  • 10–15 K
  • Drowsiness; poor judgment; impaired coordination and efficiency
• Disturbance
  • 79%–70% oxygen saturation
  • 15–20 K
  • Impaired flight control, handwriting, speech, vision, intellectual function, and judgment; decreased coordination, memory, and sensation to pain
• Critical
  
  • 69%–60% oxygen saturation
  • 20–25 K
  • Circulatory and central nervous system failure; convulsions; cardiovascular collapse; death

Question 5

Spatial Disorientation

Answer 5

SD is an individual’s inability to determine his or her position, attitude, and motion relative to the Earth’s surface.

When SD occurs, pilots are unable to see, believe, interpret, or prove information derived from their flight instruments. They instead rely on false information provided by their senses.

Question 6

Spatial Disorientation

Three types

Answer 6

TYPE I, UNRECOGNIZED

• Most dangerouse
• Pilot does not perceive any indication of SD or think anything is wrong.
• Height/depth perception illusion

TYPE II, RECOGNIZED

• pilot perceives a problem resulting from SD but might not recognize it as SD
• May belive instrument failure when not true, or might feel a control is malfunctioning.
• Graveyard spiral

TYPE III, INCAPACITATING

• pilot experiences such an overwhelming sensation of movement that he or she cannot orient using visual cues or the aircraft instruments.
• Not fatal if copilot can gain control
• Coriolis illusion (most dangerous)

Question 7

Prevention of SD

Answer 7

Never, Never, Avoid Trust!

• Never fly VMC & IMC
• Never fly without visual ref point
• Avoid certian stressors (Fatigue & HASH)
  
  • Fatigue, Hypoxia, Anxiety, Smoking, Hypoglycomia)
• Trust Instruments

Question 8

Treatment of SD

Answer 8

DR T (DDT)

• Delay intuitive actions
• Rely on & use Instruments
  (Develop a good cross-check)
• Transfer controls

Question 9

Three sensory systems

Answer 9

• Visual
  
  • Most reliable, 80% of orientation
• Proprioceptive
  
  • Pressure on skin, muscels and joints
  • seat of the pants
• Vestibular
  
  • Inner ear detects motion and gravity
  • semicircular canals & otolith organ

Question 10

Two categories of Vestibular Illusion

Answer 10

Somotogyral illusion (semicircular canals)

• Leans
• Graveyard spin
• Coriolis illusion

Somatogravic illusion (otolith organ)

• Oculogravic
• Elevator illusion
• Oculoagravic

Question 11

Somatogravic Illusions

Answer 11

• Oculogravic
  
  • Linear acceleration and deceleration
• Elevator illusion
  
  • Upward acceleration, eyes track downward
  • Pilot senses nose is rising
• Oculoagravic
  
  • Results from downward movement of an aircraft
  • False sensation that the aircraft is nose low
  • Encountered during Autorotation

Question 12

Somotogyral illusion

Answer 12

• Leans
  
  • Fails to percive angular motion
• Graveyard spin
  
  • Fixed wing
• Coriolis illusion
  
  • Most dangerouse, head motion in a different geometrical plane

Question 13

Fatigue

Hazardous to Flight Safety:
Effects may not be apparent to pilot until serious errors are made

Answer 13

• A state of feeling tired, weary, or sleepy that results from prolonged mental or physical work, extended periods of anxiety, exposure to harsh environments, or loss of sleep.
• Boring or monotonous task can increase fatigue.
• Treatment:
  
  • The most important action for treatment of fatigue is Resting and getting enough Natural Sleep

Question 14

Fatigue stages

Answer 14

Acute

• Minor - Associated with activety over 2 regular sleeping periodes
• Irritability, Inattention, Distractibility, Loss of Accuracy / Control, Lack of Awerness of errors.
• Need one regular sleep periode to recover.

Chronic

• Serious - Inadequate recovery from several acute periodes.
• May takes weeks to recover and may require other personal problems to be resolved first.
• Insomnia, Depression, Poor Judgment - Performance - Motivation

Motivational Exhaustion (burnout)

• Very Serious - If Chronic Fatigue goes untreated for to long the body will shut down and cease to function occupationally and socially.