What does the term "flight envelope" measure in aviation?

The term "flight envelope" refers to the operational limits of an aircraft, encompassing the various parameters within which an aircraft can safely operate. This includes factors like altitude, airspeed, load factor, and maneuverability. Essentially, it defines the boundaries of safe performance, ensuring that the aircraft remains within specific values for airspeed and aerodynamic load during different flight phases, such as takeoff, cruising, and landing.

Understanding the flight envelope is crucial for pilots and engineers as it helps them avoid conditions that could lead to stalls or structural failures. The concept ensures that all operational characteristics of the aircraft are respected, promoting safe flying practices. It effectively serves as a guideline for the design and operation of the aircraft, making it pivotal in aviation safety and efficiency.