What does 'G-force' refer to in aviation?

The term 'G-force' in aviation specifically refers to the force of gravity acting on the body and is a measure of acceleration relative to free fall. In aviation and space travel, pilots and astronauts experience various levels of G-force due to maneuvers such as sharp turns, climbs, and descents.

This force is often expressed in multiples of the acceleration due to Earth's gravity (9.81 m/s²), which means that a reading of 1 G represents the normal gravitational force. When aircraft change speed or direction quickly, the occupants experience increased G-forces, which can lead to physiological effects, including G-induced Loss Of Consciousness (GLOC) if the forces are too high and not managed properly.

Other options discuss different concepts such as speed during takeoff, fuel efficiency, and turbulence strength, which are unrelated to the definition of G-force. Recognizing G-force is critical for understanding the effects of flight maneuvers on pilot performance and safety.