Definition
A straight line that touches a curve or circle at exactly one point without crossing it. At the point of contact, the tangent line runs in the same direction the curve is heading at that instant.
Plain English
An imaginary straight line drawn from a point on a curved path, pointing in the exact direction you would travel if you suddenly stopped curving and went straight.
Context Anchor
Seen in ground-reference maneuvers such as eights around pylons, especially when describing how the airplane leaves one pylon turn and lines up for the next one.
Derivation
From the Latin 'tangere,' meaning 'to touch.' A tangent line just touches the curve at one point — that single touch-point is where the term comes from.
Why Pilots Care
Staying on the correct tangent keeps the turn radius constant and the pylon properly positioned relative to the wing.
Analogy
Picture a straight ruler touching the edge of a coin at one point. The ruler is tangent to the coin because it touches the round edge without cutting across the coin.
Intuition Check
Tangent does not mean “nearly parallel” or “just close to something.” Here it means a straight path that touches a curved path at one point and then continues away from it.
Example Sentence 1
While flying eights around pylons, the line from the pilot's eye to the pylon stays tangent to the circular path of the airplane.
Example Sentence 2
If the pylon drifts forward or aft of the wing, you have left the tangent and must adjust bank angle.