Aeromedical factorsQuestion 719 of 934

For best protection, when does the AIM encourage a pilot to use supplemental oxygen at night?

  1. Above 10,000 feet
  2. Above 12,500 feet
  3. Above 5,000 feet
  4. Above 15,000 feet
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Correct answer: Above 5,000 feet

The AIM encourages oxygen above 10,000 feet during the day and above 5,000 feet at night.

Source: Aeronautical Information Manual (FAA, Basic with Change 3, 9 July 2026), AIM 8-1-2 Effects of Altitude, page 642

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Questions last reviewed: 18 October 2026