What best describes the practice of a sterile cockpit?

The practice of a sterile cockpit is best described as avoiding non-essential communication during critical phases of flight. This principle is aimed at minimizing distractions for pilots during important times, such as takeoff, landing, and while flying through certain airspace. The goal is to ensure that pilots can concentrate fully on their tasks, maintaining a high level of situational awareness and safety.

During these critical phases, maintaining a clear and focused communication environment is essential. By limiting conversations to only those that are necessary, pilots can reduce the risk of misunderstandings or errors that could arise from extraneous discussions. This helps both pilots in the cockpit and any air traffic controllers or ground personnel involved, ensuring that vital information is delivered and received promptly without distractions.

The other options involve forms of communication that do not align with the core concept of sterility in the cockpit. For instance, constant communication with air traffic control or limited communication throughout the flight does not specifically focus on reducing distractions during those critical moments when utmost attention is required.