In what situation should you use the term "expedite" during air traffic control instructions?

The use of the term "expedite" in air traffic control communications is specifically associated with situations where prompt action is necessary to avert an imminent situation, such as a potential collision or loss of separation between aircraft. This term conveys a sense of urgency and the need for immediate compliance with an instruction.

When you instruct a pilot to “expedite,” it indicates that their timely response is critical to maintaining safety and avoiding adverse outcomes. By using this term, you're not just advising them to move quickly; you are emphasizing that their compliance is essential to prevent the development of a dangerous situation.

In contrast, light traffic or favorable weather conditions do not necessitate the urgent language of "expedite," as those scenarios do not typically indicate an immediate threat. It's crucial for air traffic controllers to reserve this term for moments that truly require swift action to maintain safety within the airspace.