Plain English Meaning
Knowing what is going on around you and your aircraft -- where you are, what the airplane is doing, what the weather and terrain are like, and what is about to happen next.
Full Definition
Situational Awareness (SA) is the pilot's accurate, up-to-the-moment understanding of the aircraft's position, flight conditions, surrounding terrain and traffic, weather, fuel state, system status, and what is likely to happen next. In the context of Controlled Flight Into Terrain (CFIT) prevention, SA specifically includes knowing where the aircraft is in relation to terrain and obstacles at all times.
Context Anchor
Seen in discussions of controlled flight into terrain, , , and any where the pilot must keep a mental picture of the .