Angle of Attack
The angle of attack is the angle between a reference line on a body and the direction in which it is moving. In aviation terms, the angle of attack is known as the angle between the chord line on an airfoil and the direction of a, for example, jet stream flying. The chord line on an airfoil can be difficult to determine so another part of the aircraft may be used. It doesn’t matter where the measurement originates as long as it is used consistently.
Similar yet Different Measurements
AOA (angle of attack) can sometimes be confused with the flight path angle or the pitch angle. This is because the three measurements are similar, but still different enough to need to differentiate between them.
Flight Path Angle
To the crew, this angle is known as the angle between the horizon and the flight path vector (where the aircraft is going). It’s also referred to as the climb/descent angle. On the newer commercial airliners, this angle is calculated in reference to the ground and shown on the primary flight display. When you watch a jet stream flying away from the runway, this angle is noticeable by the naked eye.
This is the angle between the direction the aircraft is pointed and the horizon. Pitch angle can be found on the attitude indicator.