What does "VNO" represent in aviation?

VNO, known as the maximum structural cruising speed, is the speed that represents the upper limit of the green arc on an airspeed indicator. It is an important airspeed for pilots to understand because it reflects the maximum speed that can safely be used in turbulent air without risking structural damage to the aircraft. Flying at or below this speed is essential for ensuring the airframe's integrity during normal flight operations.

At speeds above VNO, the pilot should exercise caution when flying in turbulent conditions, as the stresses on the aircraft can increase, potentially leading to structural failures. Understanding VNO is crucial for maintaining the safety and handling characteristics of the aircraft during various phases of flight, particularly in turbulent or adverse weather scenarios.

This knowledge helps pilots make informed decisions regarding their flight operations, ensuring adherence to safe operating practices and aircraft limitations.