Flight Physiology Exam

ADVANCE FLYING ACADEMY

Flight Physiology Exam

The Flight Physiology Exam assesses knowledge about how the human body responds to the unique conditions of flight, including altitude, pressure changes, and the aviation environment. Understanding these physiological effects is critical for ensuring safety and health in flight operations. Below is a detailed study guide.

Key Topics to Study

1. Atmospheric Pressure and Altitude

Pressure Changes with Altitude:
- Air pressure decreases as altitude increases.
- Effects on the body include hypoxia, barotrauma, and decompression sickness.
Standard Atmospheric Layers:
- Troposphere (most flight operations), stratosphere, etc.
Cabin Pressurization:
- Aircraft cabins are pressurized to simulate altitudes between 6,000–8,000 feet to reduce physiological stress.

2. Hypoxia

Definition:
- A condition caused by insufficient oxygen in the body.
Types of Hypoxia:
- Hypoxic: Insufficient oxygen in the air (e.g., high altitude).
- Hypemic: Reduced oxygen-carrying capacity of the blood (e.g., carbon monoxide poisoning).
- Stagnant: Reduced blood flow (e.g., during high G-forces).
- Histotoxic: Inability of cells to use oxygen (e.g., from alcohol or drugs).
Symptoms:
- Cyanosis, impaired judgment, dizziness, and euphoria.
Prevention and Response:
- Use supplemental oxygen, descend to a lower altitude.

3. Barotrauma

Definition:
- Physical damage caused by pressure differences between body cavities and the external environment.
Common Types:
- Sinus Barotrauma: Pain or pressure in the sinuses.
- Ear Barotrauma: Difficulty equalizing ear pressure (e.g., during ascent/descent).
- Gastrointestinal Barotrauma: Gas expansion in the stomach or intestines.
Mitigation:
- Yawning, swallowing, using the Valsalva maneuver, or descending slowly.

4. Decompression Sickness (DCS)

Causes:
- Rapid ascent or loss of cabin pressurization, causing nitrogen bubbles in the bloodstream.
Symptoms:
- Joint pain ("the bends"), dizziness, fatigue, or skin rashes.
Prevention:
- Avoid rapid ascents and decompression; wait after scuba diving before flying.

5. G-Forces

Effects of Acceleration:
- Positive G-Forces: Blood pools in the lower body, leading to G-LOC (G-induced loss of consciousness).
- Negative G-Forces: Blood rushes to the head, causing "redout."
Mitigation:
- Use anti-G suits and perform anti-G straining maneuvers.

6. Vision in Flight

Night Vision:
- Adaptation to low-light conditions can take up to 30 minutes.
- Avoid bright lights before night flights.
Spatial Disorientation:
- Caused by conflicting signals between visual, vestibular, and proprioceptive systems.
- Rely on instruments to prevent vertigo and illusions.
Common Visual Illusions:
- Autokinesis, false horizon, and runway illusions.

7. Thermal Stress

Cold Stress:
- Risk of hypothermia or frostbite during high-altitude operations without proper insulation.
Heat Stress:
- Dehydration and heatstroke risk in hot environments.
Mitigation:
- Proper hydration, clothing, and environmental controls.

8. Fatigue and Sleep

Types of Fatigue:
- Acute, chronic, and operational fatigue.
Circadian Rhythms:
- Disruption caused by long-haul flights or irregular schedules (jet lag).
Countermeasures:
- Proper rest, strategic napping, and caffeine use.

9. Aviation Medical Factors

Alcohol and Drugs:
- FAA regulations on minimum wait times after consuming alcohol (8 hours, or 24 hours for international flights).
- Effects of medication on alertness and performance.
Medical Certification:
- Requirements for physical and mental fitness for pilots and crew.
Illness and Flying:
- Restrictions on flying with colds, flu, or other conditions affecting sinuses or ears.

10. Human Performance and Limitations

Stress:
- Chronic stress impairs decision-making and reaction times.
Nutrition and Hydration:
- Importance of balanced meals and avoiding dehydration during flights.
Noise and Vibration:
- Long-term exposure can cause fatigue and hearing loss. Use hearing protection.

Sample Questions

Multiple Choice:
Which type of hypoxia is caused by an inability of the blood to transport oxygen efficiently?
- A. Hypoxic
- B. Hypemic
- C. Stagnant
- D. Histotoxic
(Correct Answer: B - Hypemic)
True/False:
Rapid decompression is less dangerous than gradual decompression because the symptoms are immediately noticeable.
(Correct Answer: True)
Scenario Question:
A pilot at 25,000 feet starts feeling light-headed and unable to concentrate. What immediate action should they take?
Fill-in-the-Blank:
The __________ maneuver is used to equalize pressure in the ears during ascent or descent.
(Correct Answer: Valsalva)
Practical Problem:
A passenger complains of joint pain and fatigue shortly after a rapid descent due to an emergency. What condition might they be experiencing, and how should it be addressed?

Study Tips

Understand Physiology Basics:
- Study how altitude, pressure, and environmental factors affect the body.
Learn Emergency Protocols:
- Memorize procedures for responding to hypoxia, decompression, and other in-flight conditions.
Use Simulations:
- Practice scenarios in flight simulators or altitude chambers to understand physiological responses.
Review Case Studies:
- Analyze incidents involving flight physiology issues for real-world insights.
Stay Updated:
- Keep current with aviation medical regulations and best practices.