What do Red W's indicate on a flight progress strip?

Red W's on a flight progress strip specifically indicate conflict or violation issues that require immediate attention from air traffic controllers. This visual alert serves as a critical tool for controllers, alerting them to situations where two aircraft may be on a collision course, or where an aircraft may be deviating from prescribed airspace regulations or safety protocols.

By marking these issues with red, controllers can quickly prioritize their response, ensuring proper separation of aircraft and the safety of flight operations. This is an important aspect of air traffic management, as it plays a key role in maintaining safety standards in busy airspace.

In this context, the other options do not accurately represent what the Red W’s signify. Weather warnings typically would not be marked in this manner on a flight progress strip, nor would indications related to aircraft emergencies or time zone changes. Red W's are specifically linked to conflicts or violations, reinforcing the need for timely and effective intervention by air traffic control.