• A type of force feedback used in the automatic flight control systems of some aircraft. Artificial feel produces an opposition to the pilot's movement of the controls that is proportional to the aerodynamic loads acting on the control surfaces

• For larger aircrafts where PCUs (Power Control Units) are used, the pilot has no direct feedback ‘feel’. Therefore, the designer has to use artificial feel to ensure that the pilot senses the magnitude of the effect that the control movements have

• In modern aircrafts there are two types of artificial feel system

o Spring Feel System o Q Feel System

Basic Q Feel System Hydraulic Q Feel System

Spring Feel SystemSpring Feel System

As pilot inputs a signal to deflect control surface, the resistance of the spring is felt

Greater the input greater the resistance

Effective at lower speeds where greater deflections are required

Basic Q Feel SystemBasic Q Feel System

Q is referred to as dynamic pressure found by subtracting static pressure from pitot pressure

Pitot pressure directed at one inlet and static pressure in other resulting in differential dynamic pressure, which acts to bias the system

Linear movement of piston leads to feel resistance to pilot i.e. greater the movement greater the feel

Increase in speed increases the value of Q which acts against the pilot although requiring only small deflections

Hydraulic Q Feel SystemHydraulic Q Feel System

Q feel pot is replaced by small hydraulic actuator and a servo valve operated by dynamic pressure

Diaphragm separates pitot and static pressure with their differential dynamic pressure biases the servo valve thus allowing hydraulic pressure into the actuator

This mechanism produces a force acting back on the stick