The V-G diagram also teaches that an airplane can be protected from excessive positive and negative G.
The area to the right of the curvilinear lines and outside the normal operating envelope is the "structural damage region." In the V-G diagram on the opposite page, it's depicted in orange.
It may be stated an airplane has "two V-G diagrams." i.e..
Suppose for a particular airplane at gross weight, [V.sub.A] is 117 knots, as the V-G diagram depicts, and suddenly, an upward wind gust causes airspeed to increase by 15 knots to 132 knots, a value well in excess of [V.sub.A].