Which regulation outlines the requirements for flying for hire?

The regulation that outlines the requirements for flying for hire is found in 14 CFR Part 135. This part specifically governs the operation of commuter and on-demand operations, detailing the requirements for certification, operational procedures, and maintenance for operators engaged in flying commercially.

Part 135 applies to entities that provide air transportation services for compensation or hire, including air taxis and charter services. It establishes safety standards, operational specifications, and training requirements necessary for these kinds of operations and ensures that they meet the regulatory requirements for commercial air services.

The other regulations mentioned serve different purposes. For example, 14 CFR Part 91 addresses general operating and flight rules, covering non-commercial flights, while Part 119 deals with certification for air carriers and commercial operators but does not specify operational requirements. Part 121 is focused on scheduled air carrier operations, which is generally more stringent than Part 135 but distinct in its focus on larger, regularly scheduled airlines.