Which statement best describes an envelope of CG and weight?

• A. It lists allowable engine configurations
• B. It is a chart of takeoff speeds for all CG
• C. It defines the region in weight-CG space where the aircraft can safely operate
• D. It sets fuel quantity limits

Answer: (C)

The weight-CG envelope is the safe operating region for the airplane, defined on a weight versus center-of-gravity chart. It marks all combinations of total weight and CG location that preserve adequate stability, controllability, and structural limits. If the aircraft’s weight and CG fall outside this boundary, you may not have enough elevator authority to flare or recover from a stall, or you could exceed structural and handling margins. So, the envelope ensures safe, controllable flight across the operating range. Engine configurations, takeoff speed charts, and fuel limits are related concerns, but they aren’t what the envelope itself defines; the envelope specifically delineates allowable weight-CG combinations, accounting for how weight and CG interact with safety and performance.