Adjust gross weight, maximum lift coefficient, never-exceed speed, and certification category to see how the flight envelope (load factor vs. airspeed) reshapes. Hover or tap the corner points on the diagram for an explanation of each structural design case.
The V-n (velocity vs. load factor) diagram is the single most important chart in aircraft structural design. Every corner and boundary on it represents a design load case — a specific combination of airspeed and g-loading that the airframe must be strong enough to survive without permanent deformation (limit load) or failure (ultimate load, typically 1.5× limit).
The wing spar, skin, and attachment fittings are sized not for "typical" flight, but for the worst-case corners of this envelope: maximum positive g at maneuvering speed, maximum positive g at VNE, and the negative-g equivalents. A structure sized only for cruise flight would fail the first time a pilot pulled hard in a steep turn or hit a strong gust at high speed.
This is also why maneuvering speed VA matters so much operationally: below VA, the wing stalls before the airframe can be overstressed by full control deflection — a built-in aerodynamic fuse. Above VA, that protection is gone, and abrupt full-deflection inputs can exceed the structural limit before the wing stalls.