Angle of climb

In aerodynamics, climb gradient is the ratio between distance travelled over the ground and altitude gained, and is expressed as a percentage.

As the latter gives the quickest way for gaining altitude levels, regardless of the distance covered during such a maneuver, it is more relevant to cruising.

The maximum angle of climb on the other hand is where the aircraft gains the most altitude in a given distance, regardless of the time needed for the maneuver.

This is important for clearing an obstacle, and therefore is the speed a pilot uses when executing a "short field" takeoff.

Best angle of climb (BAOC) airspeed for an airplane is the speed at which the maximum excess thrust is available.