What is the required action when losing sight of the runway during a circling approach?

When losing sight of the runway during a circling approach, the appropriate action is to execute the missed approach procedure. This is critical because a circling approach requires visual reference to the runway in order to safely and accurately land. If visibility of the runway is lost, continuing the approach can lead to increased risks of navigation errors, loss of situational awareness, or an accident.

Executing the missed approach procedure is a measured response that ensures safety. It typically includes climbing to a predetermined altitude, following specific waypoints, and entering the published missed approach route. This allows the pilot to safely re-establish control of the flight, avoid terrain, and set up for another approach if conditions allow.

Maintaining VFR until landing is not advisable because the pilot must remain visually oriented with runway cues. Continuing to circle could lead to dangerous scenarios if the pilot is unable to regain visual contact with the runway. A go-around is a valid maneuver when a landing cannot be safely executed, but in the context of a circling approach, the proper action when losing sight of the runway is to follow the missed approach procedure to ensure a safe operation.