A radio communication can be omitted if the pilot is already aware of the ___________.

In aviation communication, the necessity of certain information can vary based on the awareness and context of the pilot. When it comes to ground frequency numbers, these are typically used for communication with ground control when an aircraft is on the ground. If a pilot is already familiar with this specific frequency—perhaps due to prior communication with ground control or a standard operating procedure at that airport—they may find it redundant to repeat the information. Thus, an omission can be made to streamline communications without compromising safety or information transfer.

In contrast, other options such as flight duration, area of jurisdiction, and altitude and bearing are fundamental pieces of information that are critical for situational awareness and operational safety, making them less likely to be omitted from communication. Ground frequency numbers, being more procedural and often discovered in pre-flight briefings or standard resources, present a scenario where the pilot’s prior knowledge allows for effective communication without unnecessary repetition.