What action should the co-pilot take during a precision approach when reaching decision altitude?

During a precision approach when reaching decision altitude, the appropriate action for the co-pilot is to call "Continue." This call serves as an indication that the aircraft is in a position to proceed with landing, provided the required visual references or criteria are met. Precision approaches, like the Instrument Landing System (ILS), allow for a high level of accuracy to help pilots land under low visibility conditions.

If the decision altitude is reached and the necessary visual cues are visible, the call to "Continue" confirms to the pilot that a landing can be safely executed. This action is critical in maintaining clear communication and situational awareness in the cockpit, ensuring that both pilots are aligned in their approach.

Other actions listed, such as calling for a go-around or lowering the landing gear, are appropriate in different contexts. For instance, a go-around may be necessary if visual references are not established or safe landing conditions are not met; however, reaching decision altitude implies that those conditions are being assessed at that moment. Lowering the landing gear is a procedure that would typically be completed prior to the final approach phase, rather than a direct response to reaching decision altitude.