Fit to fly for hire: the body, the rules, and the biased mind

Ear and sinus blocks, cold and hypothermia, the nitrogen a scuba dive leaves behind, the alcohol and drug rules and what the substances actually do, and the two biases that make a competent pilot see what they expected.

15 min read · Commercial operations

After this lesson you can

  • Explain how ear and sinus blocks form, when they strike, and how to relieve or avoid them.
  • State the waiting periods after scuba diving before flight, and why they exist.
  • Quote the alcohol limits of 14 CFR 91.17 and the medication guidance the PHAK gives, and describe the effects the rules are protecting against.
  • Recognize confirmation bias and expectation bias in your own decisions and name a defense against each.
  • Say honestly what the handbooks do and do not cover about cold exposure.

The private pilot learns aeromedical factors as a list of things that can happen to a body in an airplane. The commercial pilot is asked to apply them to a schedule, a customer and a paycheck, which is where the list turns into decisions: whether to fly with a cold, how long after a dive, what a hangover actually does at altitude, and whether the good news you are seeing in the weather is real or is the news you wanted.

The Pilot's Handbook of Aeronautical Knowledge supplies the physiology and the regulations. The last section of this lesson is about something the handbooks discuss without naming: the two biases the Airman Certification Standards list as a risk under human factors, and the reason a commercial pilot is more exposed to them than a private one.

The rest of this lesson

  1. 1.Ear and sinus blocks: trapped gas on the way down
  2. 2.Cold and hypothermia: what the handbooks say, and what they do not
  3. 3.After a scuba dive: the nitrogen you brought aboard
  4. 4.Alcohol and drugs: the regulations
  5. 5.Alcohol and drugs: the effects the rules protect against
  6. 6.Confirmation bias and expectation bias

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

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

Key terms

Try to recall each definition before turning the card.