Dynamic Control Loading
What is dynamic control loading?
Control loading or force feedback is the feeling of resistance in the flight controls when they are moved from their neutral position, the dynamic bit, refers to the fact that control loading feel changes with different flight conditions rather than having a constant fixed force.
In a light aircraft the control surfaces (ailerons elevator and rudder) are connected to the flight controls (control yoke and rudder pedals) by cables so that moving the control in the cockpit pulls a cable connected to the control surface and deflects it into the air flow causing the planes attitude to change.
When a light aircraft is flying, or has air flowing over the control surfaces during takeoff and landing, there is a force felt in the controls created by air rushing over the control surfaces, this force is acting against the pilots inputs and pushes the yoke and pedals to their trimmed or neutral position, it is felt in the controls as a springiness / resistance that increases with airspeed.
Force feedback in jets
Commercial jets fly too fast and have control surfaces that are too big to be operated with just cables so they use hydraulic or electrical actuators to move the controls commanded by control inputs from the flight controls. This system is great at moving big control surfaces, but without the cables linked to the controls as in a light aircraft, there is no feedback - the pilots can’t feel if the plane is going fast or slow, or is about to stall.
At the dawn of the jet age, there were accidents involving hydraulic flight controls systems due to the lack of feel, so an artificial feel system was developed to mimic the effect of aerodynamic forces on the flight controls.
Simulating force feedback
Aside from the motion system, the dynamic force feedback in our simulator is most complex element to simulate. Our sim uses electric motors to create the control feel, it does this by varying the output torque to the motors based on signals governed by the aircraft flight conditions, including IAS and wind component, because it is computer controlled, we can tune the control feel to exactly match that of the real aircraft, this also allows the flight controls to move realistically according to input from the autopilot.