This rule, established aviation authorities, mandates that flight crews must refrain from non-essential activities and conversations during critical phases of flight, typically below 10,000 feet. The purpose of this rule is to ensure that the crew's focus remains solely on the safe operation of the aircraft.

During takeoff and landing, cabin crew observe what is known in aviation as the "Silent Review." This is a period of intense mental preparation where crew members are prohibited from engaging in non-essential conversation, including talking to passengers or each other. They use this time to mentally rehearse emergency procedures, such as identifying the nearest exits, recalling how to operate the door handles, and reviewing the commands they would shout during an evacuation. This typically occurs during the most critical phases of flight—the first three minutes after takeoff and the last eight minutes before landing—where the statistical probability of an incident is highest. By maintaining silence, the crew ensures they are fully "in the zone," listening for unusual sounds from the engines or fuselage and watching for any signs of fire or smoke. This discipline is a vital safety protocol mandated by international aviation authorities; while they may appear to be just sitting quietly, they are actually performing a high-stakes mental safety drill to ensure they can react within seconds if an emergency occurs.