Automatic yaw enhancement
An automatic yaw enhancement method for an aircraft having at least one propeller includes providing to a flight controller a pilot command from a pilot interface and avionic data for an airspeed, an angle of attack, and a thrust. A P-factor compensation is determined based on one or more of the airspeed, the angle of attack, and the thrust. A command to a trim device is determined based on a P-factor compensation. When a rudder bias persists, the command to the trim device is repeatedly updated until a rudder force input is nullified. The methods provide automatic pilot assistance for controlling yaw during asymmetric flight conditions and automatic turn coordination while allowing intentional side-slip for facilitating crosswind landings.
1. An automatic yaw enhancement method for an aircraft having at least one propeller, comprising:
providing to a flight controller:
a pilot command from a pilot interface; and
avionic data for an airspeed, an angle of attack, and a thrust;
determining a P-factor compensation based on one or more of the airspeed, the angle of attack, and the thrust;
providing a command to a trim device based on the P-factor compensation;
determining whether a rudder bias persists; and
repeating, until a rudder force input is nullified, the steps of determining the P-factor compensation, providing the command to the trim device, and determining whether the rudder bias persists.
2. The automatic yaw enhancement method of claim 1 , wherein providing avionic data to the flight controller further comprises providing rotational rates for yaw, pitch, and roll.
3. The automatic yaw enhancement method of claim 1 , further comprising providing to the flight controller, if the rudder bias persists, a feedback based on the command to the trim device for determining the P-factor compensation.
4. The automatic yaw enhancement method of claim 1 , further comprising holding the trim device steady for assisting the pilot when the rudder force input has been nullified.
5. The automatic yaw enhancement method of claim 1 , further comprising actuating a primary actuator via an autopilot servo for providing a portion of a force to hold the rudder in a biased position for assisting the pilot.
6. The automatic yaw enhancement method of claim 1 , further comprising providing a hydro-mechanical boost for assisting the pilot via a primary actuator in which rudder pedals provide commands to the primary actuator via a mechanical linkage and the primary actuator provides a portion of a force required to move or hold the rudder.
7. The automatic yaw enhancement method of claim 1 , further comprising providing the pilot command to a primary actuator via a mechanical linkage, wherein the primary actuator provides an entire force required without feedback returned to the pilot.
8. The automatic yaw enhancement method of claim 1 , further comprising detecting a persistent rudder servo torque and adjusting the command to the trim device until the persistent rudder servo torque is nullified.