Regulation Text
(a) Except as provided in paragraph (b) of this section, no person may operate the following airplanes without a pilot designated as second in command:
(1) Any airplane that is type certificated for more than one required pilot.
(2) Any large airplane.
(3) Any commuter category airplane.
(b) A person may operate the following airplanes without a pilot designated as second in command:
(1) Any airplane certificated for operation with one pilot.
(2) A large airplane or turbojet-powered multiengine airplane that holds a special airworthiness certificate, if:
(i) The airplane was originally designed with only one pilot station; or
(ii) The airplane was originally designed with more than one pilot station, but single pilot operations were permitted by the airplane flight manual or were otherwise permitted by a branch of the United States Armed Forces or the armed forces of a foreign contracting State to the Convention on International Civil Aviation.
(c) No person may designate a pilot to serve as second in command, nor may any pilot serve as second in command, of an airplane required under this section to have two pilots unless that pilot meets the qualifications for second in command prescribed in § 61.55 of this chapter.
[Docket FAA-2016-6142, Amdt. 91-351, 83 FR 30282, June 27, 2018]
The short answer
(14 CFR § 91.531) A second in command is required for any airplane type certificated for more than one required pilot, any large airplane, and any commuter category airplane, unless an exception applies. Any required SIC must meet the qualifications of § 61.55.
Research Notes
Common Questions
Which airplanes require a second in command under § 91.531?
A SIC must be designated for any airplane type certificated for more than one required pilot, any large airplane, and any commuter category airplane.
"no person may operate the following airplanes without a pilot designated as second in command: (1) Any airplane that is type certificated for more than one required pilot. (2) Any large airplane. (3) Any commuter category airplane." — 14 CFR § 91.531(a)
When can a large airplane be flown without a second in command?
A large airplane or turbojet-powered multiengine airplane holding a special airworthiness certificate may be flown single pilot if it was originally designed with only one pilot station, or was designed with more than one station but single-pilot operations were permitted by the flight manual or by a branch of the United States Armed Forces or a foreign State's armed forces.
"A large airplane or turbojet-powered multiengine airplane that holds a special airworthiness certificate, if: (i) The airplane was originally designed with only one pilot station; or (ii) ... single pilot operations were permitted by the airplane flight manual ..." — 14 CFR § 91.531(b)(2)
What qualifications must the second in command hold?
Where two pilots are required, the SIC must meet the qualifications prescribed in § 61.55; no one may designate or serve as SIC otherwise.
"No person may designate a pilot to serve as second in command, nor may any pilot serve as second in command, of an airplane required under this section to have two pilots unless that pilot meets the qualifications for second in command prescribed in § 61.55 of this chapter." — 14 CFR § 91.531(c)
Angle of Attack is an aviation flight-training brand founded by Chris Palmer, a two-time Master Aviation Educator and Gold Seal CFI. We decode the FARs so pilots understand not just the words, but what they mean in the cockpit.
AOA's Decoded pages are plain-English interpretation for training and reference. They are not legal advice and do not replace the official regulation. Always confirm current requirements against the authoritative source before acting.