An imaginary straight line between the leading and trailing edges of an airfoil is called?

An imaginary straight line between the leading and trailing edges of an airfoil is called?

• A. Chord
• B. Chordwise Axis
• C. Center of Gravity
• D. Center of Pressure

Answer: (A)

That line is called the chord line. It runs straight from the airfoil’s leading edge to its trailing edge and defines the chord length—the basic geometric dimension of the wing section. The chord line serves as the reference for important measurements, especially the angle of attack, which is the angle between the oncoming airflow and this line. That makes it the correct term because it uniquely describes the straight line that connects the leading and trailing edges of the airfoil. The center of gravity is the aircraft’s weight balance point, not a line on the airfoil. The center of pressure is the point where the resultant aerodynamic force acts, not the line between the edges. A chordwise axis is an axis along the chord, a different concept from the line itself.

That line is called the chord line. It runs straight from the airfoil’s leading edge to its trailing edge and defines the chord length—the basic geometric dimension of the wing section. The chord line serves as the reference for important measurements, especially the angle of attack, which is the angle between the oncoming airflow and this line. That makes it the correct term because it uniquely describes the straight line that connects the leading and trailing edges of the airfoil. The center of gravity is the aircraft’s weight balance point, not a line on the airfoil. The center of pressure is the point where the resultant aerodynamic force acts, not the line between the edges. A chordwise axis is an axis along the chord, a different concept from the line itself.