Relative wind flows in what directions concerning the aircraft's direction of flight?

Relative wind is defined as the flow of air as it relates to the aircraft in flight. It is essentially the airstream that the aircraft moves through. Relative wind flows parallel with the aircraft's flight path but in the opposite direction to that path. This means that as the aircraft moves forward, the relative wind is coming from ahead, moving backward past the aircraft’s wings and fuselage.

Understanding the concept of relative wind is critical for understanding how lift is generated and how an aircraft reacts to control inputs. The wings must interact with this relative wind to create lift, and control surfaces respond to changes in the relative airflow to maneuver the aircraft. Thus, it is important to grasp that relative wind is not just a simple concept, but rather an essential part of the aerodynamics that governs flight.