SPC Aeromedical Factors 3 — Questions and Answers
Question 1: Which physical symptom is MOST commonly associated with hyperventilation in flight?
- Increased heart rate and high blood pressure
- Tingling sensations and muscle spasms (Correct answer)
- Decreased respiratory rate
- Redness of the skin and sweating
Correct answer: Tingling sensations and muscle spasms
Hyperventilation causes a drop in blood CO2, leading to respiratory alkalosis which produces tingling, numbness, and muscle cramping.
Question 2: What is the recommended in-flight treatment for a pilot who is hyperventilating?
- Inhale pure oxygen from a supplemental system
- Slow the breathing rate and talk aloud or breathe into a bag (Correct answer)
- Increase cabin altitude to force slower breathing
- Consume water and rest
Correct answer: Slow the breathing rate and talk aloud or breathe into a bag
Consciously slowing breathing—or talking aloud to force a normal rhythm—restores CO2 balance and relieves hyperventilation symptoms.
Question 3: A pilot notices a faint smell of exhaust in the cockpit. The BEST immediate action is to:
- Increase airspeed to ventilate the cockpit faster
- Close all vents, don oxygen if available, and land as soon as practicable (Correct answer)
- Open cabin heat to purge the system
- Continue flight and monitor for further symptoms
Correct answer: Close all vents, don oxygen if available, and land as soon as practicable
Exhaust odor suggests possible CO infiltration; pilots should close heat/vents, use oxygen if available, and land promptly before impairment worsens.
Question 4: Under FAA regulations, pilots must use supplemental oxygen for flights above 14,000 feet MSL for periods of:
- More than 30 minutes
- The entire time at that altitude (Correct answer)
- More than 1 hour
- More than 2 hours
Correct answer: The entire time at that altitude
FAR 91.211 requires that each required pilot flight crewmember use oxygen at all times when flying at cabin pressure altitudes above 14,000 feet MSL.
Question 5: Which factor does NOT typically contribute to an increased susceptibility to hypoxia?
- Smoking
- Physical fitness (Correct answer)
- Anemia
- Alcohol consumption the previous day
Correct answer: Physical fitness
Being physically fit does not increase hypoxia susceptibility; smoking, anemia, and residual alcohol all reduce the blood's effective oxygen-carrying capacity.
Question 6: The term 'time of useful consciousness' (TUC) refers to:
- How long a pilot can fly before fatigue requires rest
- The period from hypoxia onset to when a pilot can no longer take corrective action (Correct answer)
- The time available after an engine failure to restart the engine
- Maximum allowable duty time under FARs
Correct answer: The period from hypoxia onset to when a pilot can no longer take corrective action
TUC is the interval after hypoxia begins during which a pilot can still recognize the problem and take effective corrective action.
Question 7: A pilot flying at night notices that looking directly at a dim light makes it disappear. This phenomenon is called:
- Night myopia
- Central blind spot effect (Correct answer)
- Empty-field myopia
- Autokinesis
Correct answer: Central blind spot effect
The center of the retina (fovea) has few rod cells, creating a central blind spot at night; objects become visible when viewed slightly off-center (off-axis viewing).
SPC Aeromedical Factors 3
Which physical symptom is MOST commonly associated with hyperventilation in flight?