FAA Flight Instructor Airplane (FIA)Aerodynamics and Principles of FlightEasy
A flight instructor asks a primary student to define 'relative wind.' Which statement correctly describes it?
- AThe direction of the airflow produced by an airplane's motion through the air, which is parallel to and opposite the flight path
- BThe angle between the chord line and the horizon
- CThe wind direction relative to magnetic north as shown on a sectional chart
- DThe surface wind reported by ATIS relative to the runway in use
Show answer & explanationAnswer & explanation
Correct answer: A. The direction of the airflow produced by an airplane's motion through the air, which is parallel to and opposite the flight path
Relative wind is the airflow that results from the airplane's motion through the atmosphere. It is always parallel to and moves in the opposite direction of the airplane's flight path, and together with the chord line it defines the angle of attack.
Why the other options are wrong
- B. This describes angle of attack, not relative wind itself.
- C. Describes a navigational wind direction, not relative wind.
- D. Confuses relative wind with reported surface wind used for runway selection.
Relative Wind
The airflow relative to an airfoil, created by the airplane's movement through the air, always parallel to and opposite the flight path.
- Opposite direction of flight path
- Combines with chord line to form angle of attack
- Independent of surface/reported wind
Memory trick: Relative wind always runs 'backwards' along the flight path.