What action should controllers take if they observe a potential collision?

When controllers observe a potential collision, issuing immediate vectors and instructions to the involved aircraft is the appropriate action. This proactive measure is essential for ensuring the safety of all aircraft in the vicinity. By providing specific headings, altitudes, and instructions, controllers can effectively guide pilots away from danger and ensure safe separation between the aircraft.

This process involves rapid decision-making and clear communication to prevent misunderstandings or delays that might exacerbate an already critical situation. It also reflects the responsibility of air traffic controllers to maintain safe distances between aircraft, and their guidance is crucial for pilot situational awareness in times of heightened risk.

In contrast, waiting for the aircraft to resolve the situation could lead to catastrophic outcomes, as the pilots involved may not be aware of the potential collision without immediate guidance. Changing the flight path of one aircraft might also be an action taken, but it would typically follow the initial issuance of vectors and instructions to ensure safety first. Notifying ground control does not directly address the immediate risk to the aircraft involved and is not the primary concern during an imminent collision threat.