Which FAR part relates closely to the safe operation of commercial flights?

The correct reference for the safe operation of commercial flights is Part 135 of the Federal Aviation Regulations (FARs). This part specifically governs the operations of commuter and on-demand operations, including charter flights and air taxi services. It establishes the requirements for operating under commercial conditions, focusing on safety standards, operational procedures, maintenance, and certification processes for both aircraft and operators.

Part 135 includes detailed regulations regarding pilot qualifications, aircraft maintenance schedules, operational limits, and safety equipment requirements, which are critical for ensuring that commercial flights are conducted safely and efficiently. This includes rules on minimum flight crew responsibilities and additional safety measures that differ from those in non-commercial operations.

In contrast, Part 91 covers general operating and flight rules for all aircraft, including private and non-commercial operations, while Part 145 pertains to the repair stations that provide maintenance and alterations to aircraft. Part 23 focuses on the airworthiness standards for normal, utility, acrobatic, and commuter category airplanes, rather than operational details specific to commercial flights.