The Flight Envelope is a graphical tool used to calculate the actual Center of Gravity (COG) and weight of an aircraft based on the loading conditions. It is a critical tool to ensure that the loaded aircraft is within the allowable COG limits, which is essential for safe flight operations.
Components of the flight range limit:
Weight vs. moment arms:
The diagram contains graphical curves showing the weight against the moment arms for different areas. These areas can be, for example, front cargo compartments, rear seats or fuel tanks. Each area has a specific position along the longitudinal axis of the aircraft that determines the moment arm.
Loading lines or load zones:
Each line in the diagram represents how the center of gravity shifts when a particular station or compartment is loaded. These lines help to visualize the effects of loading on the COG.
COG envelope diagram:
The diagram also contains a COG envelope, see picture, which shows the permissible range for the COG. The final weight and COG combination can be plotted on this graph to ensure they are within the allowable limits.

Instructions or loading sequence:
Some load charts provide instructions or a recommended loading sequence to maintain the balance of the aircraft. This helps to achieve optimum loading and ensure that the COG remains within the permissible limits.
Use of the flight range limit
Quick calculation of the COG:
The flight range limit enables the loaded COG to be calculated quickly without manual calculations. This saves time and reduces the risk of errors.
Avoidance of overloading or COG violations:
By using the load diagram, overloading or violations of the COG limits can be avoided. This contributes to flight safety.
Application in flight planning, training and ground operations:
Flight envelope boundaries are used in various areas of aviation, including flight planning, flight crew training and ground operations. They are an indispensable tool for the safe and efficient execution of flight operations.
Overall, the flight envelope limit is an indispensable tool in aviation that contributes to the safe and efficient loading of aircraft and ensures that all flights are carried out within the permitted COG limits.
