What is the angle formed between the aircraft's heading and the destination direction called?

The angle formed between the aircraft's heading and the direction to the destination is referred to as the "Relative Bearing." This term specifically denotes how far off your current heading you need to turn to reach a specific direction.

In practical navigation, relative bearing is crucial because it helps pilots and navigators understand the necessary adjustments to align the aircraft's course towards their intended destination. It is measured in degrees relative to the aircraft's current heading; for example, a destination that is directly to the right of the aircraft's current heading would have a relative bearing of 90 degrees.

Understanding relative bearing is essential for safe and effective navigation, especially in dynamic flight environments where immediate adjustments may be necessary based on changing conditions or obstacles.