What is meant by 'spatial disorientation' for pilots?

Spatial disorientation refers to a condition where a pilot cannot correctly ascertain the aircraft's position, motion, and attitude relative to the Earth’s surface. This can occur due to a reliance on visual cues that may be misleading, especially in conditions of poor visibility or when flying at night. When pilots experience spatial disorientation, they may misinterpret the aircraft's orientation—believing it to be climbing when it is actually descending or vice versa. Such a misperception can lead to dangerous situations, including loss of control.

Understanding aircraft attitude is crucial for maintaining proper flight control and avoiding accidents, particularly in situations where external references are limited. Therefore, the ability to interpret the aircraft's attitude accurately is essential for safe piloting. This is why being unable to properly interpret the aircraft's attitude is at the core of spatial disorientation.