What is a CG envelope?

• A. A defined region in weight-moment or weight-CG space showing acceptable combinations
• B. A fixed maximum takeoff weight
• C. A diagram of CG location
• D. A procedure for fuel management

Answer: (A)

A CG envelope is the defined region in weight and center-of-gravity space that shows all the loading combinations that keep the aircraft within its design limits for stability, control, and structure. On a chart, weight is one axis and CG location (or moment/arm) is the other, and the allowable conditions form a boundary or “envelope.” Any loaded condition that lies inside this boundary respects the required forward and aft CG limits and the maximum/minimum weight, so the airplane will be controllable and structurally safe through takeoff, flight, and landing.

As weight changes, the envelope helps you verify that the CG remains within acceptable bounds; heavier weights often constrain the acceptable CG range and may require moving payload or adjusting fuel to stay inside. The envelope isn’t a single number like MTOW, and it isn’t just a diagram of where the CG could be located or a fuel procedure. It’s the safety boundary combining weight and balance into a single guide for proper loading.