This paper aims to systematically analyze the needs for single-pilot and reduced crew operations in commercial air transportation, and to develop human–autonomy teaming requirements to support future operations. In reduced crew operations, the pilot-flying operates the flight alone in the cockpit while the pilot-not-flying rests outside of the cockpit unless needed in high-workload situations. In single-pilot operations, there is only one pilot onboard to manage the flight. Many of the functions performed by the second pilot in dual-pilot operations would be replaced with an autonomous teammate. These increasingly autonomous systems will have capabilities that require it to be treated more like a member of the crew. Enhanced ground support will also support these flights. The transition from dual-pilot to single-pilot operations will require the redesign of the roles and responsibilities of the air and ground crew, crew resource management, function allocation, human–autonomy teaming, and procedures for normal and off-nominal situations. Document analysis, subject-matter-expert interviews, and pilot evaluations were conducted to analyze and compare concepts of operation, develop domain knowledge models, and develop human–autonomy teaming requirements to support pilot decision making and operations.