What regulation created sterile cockpit?

• A. FAR 25.1309
• B. FAR 91.205
• C. FAR 117.3
• D. FAR 121.542

Answer: (D)

The main idea tested is the discipline of cockpit activity during critical phases of flight. The sterile cockpit rule is a regulation that requires pilots to refrain from nonessential activities and conversation during taxi, takeoff, and landing, and during any flight operation conducted below 10,000 feet MSL. This focus helps ensure crew attention remains on the tasks that matter most when workload is highest and the risk of error is greatest. The regulation that created and codified this requirement is FAR 121.542, which applies to Part 121 scheduled operations and sets the standard for minimizing distractions during these periods, with safety exceptions only for necessary communications or emergencies. The other listed regulations address different areas—design requirements, minimum equipment, and flight-time/duty definitions—and do not establish the sterile cockpit concept.