What is the maximum operating speed (Vmo) from sea level to 21,000 feet?

The maximum operating speed, commonly referred to as Vmo, is a critical limitation for the King Air 350 that specifies the highest airspeed that can be safely attained at varying altitudes. For the King Air 350, the Vmo from sea level to 21,000 feet is set at 263 KIAS (Knots Indicated Airspeed). This value is determined based on the aircraft's design limits, ensuring that the airframe and control surfaces operate within safe parameters to prevent issues like structural failure or loss of control. Operating above this speed, especially in turbulent conditions, could lead to adverse aerodynamic effects.

The other choices represent speeds that fall outside of the established limits for safe operation of the King Air 350. It's important to adhere to the Vmo to maintain the safety and integrity of the aircraft during flight.