An approach slope is the path that an airplane follows on its final approach to land on a runway. It takes its name from the fact that this path is ideally a gentle downward slope. A commonly used approach slope is 3° below the horizontal. Fixed-wing aircraft is a term used to refer to what are more commonly known as aeroplanes in Commonwealth English (excluding Canada) or airplanes in North American English. ... A runway is a strip of land on an airport, on which aircraft can take off and land. ... In mathematics, the slope (or gradient, especially where three or more dimensions are discussed) of a straight line (within a Cartesian coordinate system) is a measure for the steepness of said line. ...

The term glide slope is often incorrectly applied to mean approach slope. This is because an aircraft aiming for a perfectly failsafe landing or one that is landing without engine power will use its glide slope as its approach slope. However, in non-emergencies, approach slopes for non-gliders are usually shallower than the glide slope as this makes for a softer landing. Glide ratio is an aviation term that refers to the distance an aircraft will move forward for any given amount of lost altitude (the cotangent of the downward angle). ... Gliders are un-powered heavier-than-air aircraft. ...