Which is a common early symptom of hypoxia that makes it especially dangerous?
- Sharp pain in the ears and sinuses
- Severe chest pain and shortness of breath
- A feeling of well-being with impaired judgment
- Loss of hearing and a ringing sound
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C. A feeling of well-being with impaired judgment
Hypoxia often brings euphoria and poor judgment, so the pilot feels fine while performance falls apart. Other signs include headache, tingling, slowed reactions and blue fingernails or lips. Ear and sinus pain come from trapped gas, not lack of oxygen.
Reference: FAA-H-8083-25 (PHAK), Chapter 17; AIM Chapter 8
Carbon monoxide from a leaking exhaust heater causes which type of hypoxia?
- Hypoxic hypoxia
- Hypemic hypoxia
- Stagnant hypoxia
- Histotoxic hypoxia
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B. Hypemic hypoxia
Carbon monoxide binds to hemoglobin far more readily than oxygen, so the blood cannot carry enough oxygen: hypemic hypoxia. Hypoxic hypoxia is the altitude type, where there is too little oxygen pressure in the air itself.
Reference: FAA-H-8083-25 (PHAK), Chapter 17; AIM Chapter 8
In cruise with the cabin heater on, a pilot notices a headache, drowsiness and a faint exhaust smell. What should be done first?
- Turn the heater to full to clear the smell
- Descend 1,000 feet and continue the flight
- Lean the mixture to reduce the exhaust fumes
- Turn off the heater and open the fresh air vents
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D. Turn off the heater and open the fresh air vents
These are signs of carbon monoxide poisoning from an exhaust leak into the heater shroud. Shut off the heater, get fresh air, use oxygen if available and land as soon as practical. A small descent does nothing about the source.
Reference: FAA-H-8083-25 (PHAK), Chapter 17; AIM Chapter 8