Hypoxia

The four types of oxygen starvation, how to recognize each one, and what 14 CFR 91.211 requires.

13 min read · Human factors

After this lesson you can

  • Name the four types of hypoxia and the mechanism each one breaks.
  • List the early symptoms of hypoxia and explain why self-diagnosis is unreliable.
  • Read a time-of-useful-consciousness table and use it to plan an emergency descent.
  • State the oxygen requirements of 14 CFR 91.211 from memory.

Hypoxia means "not enough oxygen." The brain is the organ most sensitive to the shortage, and it is also the organ that is supposed to warn you something is wrong. That is the trap: hypoxia degrades judgment first, so the pilot experiencing it usually feels fine, sometimes better than fine, right up until the point where acting on that feeling becomes dangerous.

Hypoxia is not only a high-altitude problem. Carbon monoxide, blood loss, cold, and alcohol can all starve your cells of oxygen at sea level, with no altimeter to warn you. Knowing the four mechanisms is what lets you recognize hypoxia when the cause is not the one you were expecting.

The rest of this lesson

  1. 1.Four mechanisms, four types
  2. 2.Recognizing it in yourself
  3. 3.Time of useful consciousness
  4. 4.Treating hypoxia
  5. 5.What 14 CFR 91.211 requires
  6. 6.Hypoxia without the altitude

These 6 sections, their figures, the checks along the way and the end-of-lesson quiz come with the PPL track. Paid once, yours for good.

See what the PPL track costsEvery module 1 is free to read, no account, no card.

Key terms

Try to recall each definition before turning the card.