Which terrain flight mode keeps aircraft closest to the ground to avoid detection?

• A. NOE
• B. Low Level
• C. Contour
• D. High Level

Answer: (A)

Nap-of-the-Earth flight mode hugs the terrain, keeping the aircraft as close to the ground as possible by following the ground’s irregularities in real time. It uses terrain data, radar altimeter data, and inertial navigation to maintain the smallest practical clearance, which is ideal for minimizing detection.

In comparison, Low Level implies staying near the ground but not necessarily tracking every contour; Contour mode follows terrain by maintaining a constant offset above the surface, which is typically higher than NOE’s closest approach; High Level flies at a much higher altitude, far from the ground.

So for staying closest to the ground to avoid detection, Nap-of-the-Earth is the best choice.