14 C.F.R. § 27.1523 Minimum flight crew.
Title 14 - Aeronautics and Space
The minimum flight crew must be established so that it is sufficient for safe operation, considering— (a) The workload on individual crewmembers; (b) The accessibility and ease of operation of necessary controls by the appropriate crewmember; and (c) The kinds of operation authorized under §27.1525.
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart G—Operating Limitations and Information
Operating Limitations
§ 27.1523 Minimum flight crew.