Final answer:
The barb on a procedure turn in aviation navigation indicates the direction an aircraft should turn during a procedural segment of an approach. It is not for depicting altitude restrictions, speed limits, or distances to the missed approach point.
Step-by-step explanation:
The barb on a procedure turn in aviation navigation typically depicts the turn direction that an aircraft must follow during the procedure turn segment of an instrument approach. The procedure turn is used to reverse direction to establish the aircraft on the intermediate or final approach course. It is marked as a barbed arrow in aeronautical charts, specifically on the approach plate, indicating the side of the outbound course where the turn is to be executed.
The purpose of the procedure turn is not to provide altitude restrictions, speed limits, or distance information to the missed approach point. Given this information, the correct answer to the student's question is: