How can you identify the highest obstacle on an approach plate?

The highest obstacle on an approach plate is identified by a conspicuous arrow pointing to it, which is specifically designed to draw attention to this crucial information. This visual representation helps pilots quickly and easily locate the highest obstacle that could affect their approach and landing. Recognizing this obstacle is vital for ensuring safety, as it represents a potential risk during the flight approach phase.

In terms of other options, markings, colors, or legends serve important purposes on an approach plate, but they do not specifically indicate the highest obstacle with as much clarity and immediacy as the arrow does. The use of a pointing arrow is a standard practice in aviation charts to highlight specific features, making it the most effective method for identifying the highest obstacle.