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Which airplanes must be operated with a designated second in command under 91.531?

Airplanes type certificated for more than one required pilot.

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  1. Airplanes type certificated for more than one required pilot ✔
  2. Any airplane with more than four seats
  3. Any turbocharged airplane

Why: Section 91.531 requires a designated second in command for any airplane type certificated for more than one required pilot, any large airplane, and any commuter category airplane. Exceptions apply for certain special airworthiness certificate airplanes.

Huh, didn't know that: The SIC must meet the qualifications in 61.55.

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Why couldn't the fighter jet pilot talk to his co-pilot? He hadn't broken the sound barrier yet.
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References

Answer: Airplanes type certificated for more than one required pilot. Section 91.531 requires a designated second in command for any airplane type certificated for more than one required pilot, any large airplane, and any commuter category airplane. Exceptions apply for certain special airworthiness certificate airplanes.

  1. 14 CFR 91.531 Second in command requirements (Cornell LII eCFR mirror) www.law.cornell.edu/cfr/text/14/91.531
    type certificated for more than one required pilot
    Checked 2026-10-10.

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