What is the assessment area limited to for a Diverse Departure?

The assessment area for a Diverse Departure is appropriately defined as being limited to 25 nautical miles from the airfield and extending up to 46 nautical miles in mountainous regions. This specification allows for the safe clearance of terrain and ensures that aircraft can maintain a safe flight path following takeoff.

When departing from an airfield, especially in areas with mountainous terrain, it is essential to have a larger clearance area to account for the elevation changes and the potential risks associated with the terrain. The additional distance in mountainous areas provides a necessary buffer, enhancing safety by allowing for a greater margin for error during the initial climb phase, where an aircraft may encounter an obstruction.

The other options do not capture the full extent of the assessment area, either by misrepresenting the range or by failing to consider the additional requirements associated with mountainous terrain.