Definition
A direction along an airfoil that runs parallel to the chord line — the straight line from the leading edge to the trailing edge of a wing, propeller blade, or rotor blade. Chordwise measurements, forces, and flows are oriented front-to-back along the airfoil, as distinct from spanwise, which runs from root to tip.
Plain English
Front-to-back along a wing or blade — the direction air flows from the leading edge to the trailing edge.
Context Anchor
Seen in aerodynamics, wing and propeller descriptions, airflow discussions, and aircraft maintenance notes about surface condition or damage location.
Derivation
From 'chord' — the straight line connecting the leading and trailing edges of an airfoil — plus '-wise', meaning 'in the direction of'. So chordwise simply means 'in the direction of the chord'.
Why Pilots Care
Chordwise helps a pilot or mechanic describe exactly where something is on a wing or blade. For example, a scratch, ice shape, or airflow pattern may matter differently depending on whether it runs front-to-back or along the span.
Analogy
Think of placing a ruler from the front edge of a wing straight back to the rear edge. That ruler is pointing chordwise.
Intuition Check
Chordwise does not refer to a musical chord or a rope cord. In aviation, chord means the front-to-back reference line of a wing or blade shape.
Example Sentence 1
Airflow over the wing moves chordwise, from the leading edge back to the trailing edge.
Example Sentence 2
Chordwise loads must be considered when designing the wing's internal structure.