In the context of aviation and aerospace, "Altitude" and "Height" are two related but distinct concepts that refer to the vertical position of an aircraft or object in relation to the Earth's surface. While often used interchangeably, there is a subtle difference between the two terms:

Altitude: Altitude refers to the height of an aircraft or object above a specific reference level, typically mean sea level (MSL). It is measured from the center of the Earth and is usually expressed in feet (ft) or meters (m). Altitude is an absolute measure, meaning it is a fixed value that does not change with location or atmospheric conditions.

Height: Height, on the other hand, refers to the vertical distance between an aircraft or object and a specific reference point, such as the ground or a runway. Height is a relative measure, meaning it can vary depending on the location and the reference point used. For example, the height of an aircraft above a runway might be different from its height above a nearby hill.

To illustrate the difference:

• An aircraft flying at an altitude of 30,000 ft (9,144 m) above mean sea level (MSL) has a fixed altitude regardless of its location.
• However, if that same aircraft is flying over a mountain range with peaks at 10,000 ft (3,048 m) above MSL, its height above the mountain peaks would be 20,000 ft (6,096 m), even though its altitude remains 30,000 ft (9,144 m) above MSL.

In summary, altitude refers to the absolute height above a reference level (MSL), while height refers to the relative vertical distance between an object and a specific reference point (e.g., ground, runway, or obstacle).