How are runway incursions defined in aviation?

Runway incursions are specifically defined as any occurrence at an airport where there is an incorrect presence of an aircraft, vehicle, or person on the protected area of a runway. This definition is crucial in aviation, as it highlights the potential for collision or unsafe situations on a runway. Ensuring safety at airports involves strict protocols to prevent unauthorized access to runway areas, and this definition underlines the importance of monitoring all entities present in these zones.

By focusing on the incorrect presence within the runway's protected area, this definition encompasses various scenarios that could lead to accidents or dangerous situations, thereby emphasizing the need for rigorous adherence to safety regulations in aviation operations. Other options either misinterpret the scope of runway incursions or pertain to different aviation issues altogether.