Bank angle
The bank angle , also known as roll angle, is the angle of inclination of an aircraft when turning . The apparent weight acts on an aircraft as the sum of the weight and the centrifugal force . With an appropriately chosen bank angle, the lift is directed exactly in the opposite direction. This allows the aircraft to change direction without changing altitude.
In technical terminology, the bank angle is called "BA" as an abbreviation for the English term "bank angle".