- The acceleration of gravity, 980.665 cm/s2 , approximately 32.2 ft/s2 at sea level. It is used as a unit of stress measurement for bodies undergoing acceleration. This acceleration can act along any of the aircraft’s axes, but usually it refers to the one acting along the normal (vertical) axis, or from the head to the toe. It is called positive when it acts from the head toward the toes and negative when it acts from the toes toward the head. In this usage, g is the centrifugal force experienced by a body of an aircraft and is expressed as a number, which is that number times the actual weight of the body or the aircraft. If it is said that the aircraft is “pulling 4Gs,” then the pilot and the aircraft are experiencing a force that is four times their weight. The amount of g experienced by an aircraft is a function of the angle of bank. The radius of turn is dependent on the amount of g pulled (angle of bank) and speed.
Aviation dictionary. 2014.