Automated approach speed control for an airplane

A flight control system for a turboprop airplane having electronically controlled engines and having engine-governing means comprising:

• a) a device for selecting a desired airspeed;
• b) a manually operable power-setting device on a flight deck for setting the engine power to obtain the selected airspeed;
• and
• c) an engine control system for computing and controlling the required engine torque and speed as a function of ambient and engine conditions, of the selected engine speed and of the setting of said operating device;
• which flight control system also has an electronic approach speed control unit including:
• d) means to generate a power-adjustment signal in response to airspeed which signal can influence the engine control system to keep the speed of the airplane during approach at the selected value;
• and
• e) electronic means to adjust the engine power in response to the engine adjustment signal and independently of movements of said manually operable power-setting device;
• whereby speed-control adjustments can be effected while leaving the manually operable power-setting device fixed at its setpoint position.