What is MAC?

What is MAC?

• A. MAC stands for Maximum Aerodynamic Coefficient.
• B. MAC is the center of gravity distance to the wing tip.
• C. Mean Aerodynamic Chord. It is an imaginary chord from the nose of the aircraft to the tail which runs through the middle.
• D. MAC is the wing's mean angular chord.

Answer: (C)

Mean Aerodynamic Chord is the chord length of a hypothetical wing that has the same aerodynamic lift distribution as the actual wing. It provides a single reference length used to summarize the wing’s shape and to position the aircraft’s center of gravity, since CG is often expressed as a percentage of MAC from the leading edge. In practice, MAC is computed from the wing’s planform by integrating c(y)² along the span and dividing by the wing area S. The idea is a useful, simplified measure of the wing’s effective chord. The description that it’s a chord running from the nose to the tail is not how MAC is defined; it’s a representative chord along the wing, not a line across the fuselage. The other options do not reflect the standard meaning of MAC.

Mean Aerodynamic Chord is the chord length of a hypothetical wing that has the same aerodynamic lift distribution as the actual wing. It provides a single reference length used to summarize the wing’s shape and to position the aircraft’s center of gravity, since CG is often expressed as a percentage of MAC from the leading edge. In practice, MAC is computed from the wing’s planform by integrating c(y)² along the span and dividing by the wing area S. The idea is a useful, simplified measure of the wing’s effective chord. The description that it’s a chord running from the nose to the tail is not how MAC is defined; it’s a representative chord along the wing, not a line across the fuselage. The other options do not reflect the standard meaning of MAC.