How is a helicopter operating area identified?

The identification of a helicopter operating area is marked by a white letter "H," which is typically 4 metres high and has a 2 metre crosspiece. This standardization ensures that the marking is visible from a distance, facilitating safety and ease of operation for helicopter pilots. The large height and crosspiece dimensions are designed for clear identification in various operational conditions and environments, providing pilots with quick visual cues necessary for landing and takeoff.

In contrast, other markings, such as a large red circle, may be used for different purposes or in other aviation contexts but do not specifically denote a helicopter operating area. Likewise, a yellow letter "H" against a black background is less common and does not meet the standardized requirements. Finally, a dotted pattern on the ground lacks the necessary clarity and identification features required for helicopter operations. Therefore, the distinctive characteristics of the white "H" marking make it the correct identification for helicopter operating areas.