What height is a helicopter operating area sign depicted as?

The correct height for a helicopter operating area sign is 4 metres high. This specification ensures that the sign is suitably elevated to be visible to helicopter pilots and aircrew, allowing them to identify operational zones safely and effectively. A height of 4 metres strikes a balance between visibility from the air while also minimizing potential obstructions on the ground. This standard is important for safety and operational efficiency in helicopter use, as it allows for adequate clearance above common obstructions in the area, thereby facilitating safe navigation around and into helicopter operating zones.