FAR 91.601 — Subpart F Applicability

FAR 91.601 is the opening section of Subpart F of Part 91. It tells you who the rules in this subpart apply to. Specifically, Subpart F covers the operation of:

• Large aircraft (more than 12,500 lbs maximum certificated takeoff weight)
• Transport category aircraft (a specific FAA airworthiness certification category)
• Aircraft that are U.S.-registered and civil (not military or public-use)

Why it matters operationally: Subpart F adds extra requirements on top of the general Part 91 rules — things like flight engineer requirements, equipment standards, and operating limitations specific to bigger, more complex airplanes. As a student pilot in a typical training airplane (like a 172 or PA-28), Subpart F won't apply to you, but you should know where to look once you transition to larger turbine or transport aircraft. It also helps you quickly rule out rules that don't apply when studying Part 91 for your checkride.