Drag control configuration for a powered aircraft

A powered aircraft includes at least one thrust producing engine and an engine controller controllably coupled to the at least one thrust producing engine. The engine controller includes at least a first control channel and a drag control channel. The first control channel is configured to control the at least one thrust producing engine via thrust control and the drag control channel is configured to control the at least one thrust producing engine via drag control.

TECHNICAL FIELD

The present disclosure relates generally to powered aircraft control configurations, and more specifically to an aircraft engine controller including a drag control channel.

BACKGROUND

Powered aircraft are typically powered via one or more aircraft engines statically mounted to the wings, tail, or body of the aircraft. The engines utilize known processes to generate thrust and to power the aircraft. An engine controller is generally provided for each engine, however in some examples a single engine controller can be utilized to control each of the engines in a multi-engine aircraft. In such examples, a second redundant engine controller is typically incorporated in order to prevent single point failure modes. The controller controls engine parameters, such as rotational speed, fuel injection, and the like, in order to control the magnitude of the thrust generated by the engine. This in turn allows the pilot to operate the engine in any desired mode.

In order to ensure continued operation of the powered aircraft in conditions where the engine controller may become faulty, powered aircraft typically include redundant controller channels. In such a configuration, when a first control channel experiences a failure the aircraft switches from the faulty channel to the redundant channel. The redundant controller channels are identical control channels, with controller configurations for setting which control channel is in control at any given time.

SUMMARY OF THE INVENTION

In one exemplary embodiment a powered aircraft includes at least one thrust producing engine, and an engine controller controllably coupled to the at least one thrust producing engine, the engine controller including at least a first control channel and a drag control channel, wherein the first control channel is configured to control the at least one thrust producing engine via thrust control, and the drag control channel is configured to control the at least one thrust producing engine via drag control.

An exemplary method for operating a powered aircraft includes operating in a drag control mode by outputting a fixed thrust for a desired engine operational mode and maintaining a velocity of a powered aircraft within a velocity window corresponding to the fixed thrust by adjusting at least one drag producing component of the aircraft and thereby adjusting a drag of the aircraft.

An exemplary method for operating a powered aircraft includes detecting a cyber-security intrusion at an engine controller, and transitioning from a thrust control channel to a drag control channel within said engine controller in response to detecting the cyber-security intrusion.

DETAILED DESCRIPTION OF AN EMBODIMENT

FIG. 1schematically illustrates an exemplary powered aircraft10. The exemplary aircraft10includes two wing mounted engines20statically connected to the wings30of the aircraft10. Each of the engines20includes a corresponding engine controller22configured to control a thrust output of the engine20. The engine controllers22are communicatively coupled to a general aircraft controller40. While illustrated as being physically located at a cockpit of the aircraft10, the general aircraft controller40could be located at any position, and electronically connected to the cockpit controls.

Also connected to, and controlled by, the general aircraft controller40are multiple drag producing or reducing devices such as speed brakes, landing gear, sideslip, flaps, spoilers, and the like. Engaging and operating the drag producing or reducing devices alters the amount of drag on the aircraft, and thus the amount of thrust required to maintain a given operational mode of the engines20.

On a modern powered aircraft, the engine controllers22are typically electronic controllers, and utilize digital controls. By way of example, the engine controller can be a FADEC (Full Authority Digital Engine Control) system. In some cases, due to the digital nature of the engine controller22, it is possible for a cyber-security based intrusion to occur resulting in one or more of the engine controllers22incorrectly operating the corresponding engine20. In large aircraft10utilizing multiple engines, when such an error occurs, the aircraft10can shut off a compromised engine20, and the thrust output of the remaining online engines20can be increased to offset the shut off engine20.

However, on smaller aircraft10and single engine aircraft10the remaining engine(s) may be insufficient to generate a required thrust for a desired engine operational mode. The illustrated two engine20aircraft10ofFIG. 1is one such example. In order to guard against the potential cyber-security intrusion described above, each of the engine controllers22and/or the general aircraft controller40includes a drag control channel in addition to the redundant FADEC control channels.

With continued reference to the aircraft10ofFIG. 1,FIG. 2schematically illustrates an exemplary engine controller100including an auxiliary drag control channel110according to one example. The engine controller100includes a set of engine sensor inputs120connected to various engine sensors. The engine sensor inputs120provide the sensed engine information to a thrust control channel130and to the drag control channel110of a FADEC102. The thrust control channel130includes a primary channel132and a backup channel134.

Each of the thrust control channel130and the drag control channel110are configured to output control signals to a set of engine effectors150. The engine effectors150translate the thrust control outputs to various engine components to achieve a desired thrust according to known engine control techniques.

Under ordinary operating conditions, the thrust control channel130responds to pilot commands and adjusts engine thrust to maintain any given engine operational mode and velocity. By way of example, some engine operational modes can be approach power, cruise power, partial augmentor power, full augmentor power and idle power.

If a cyber-security intrusion of the engine controller100occurs it is possible for an outside actor to influence the control of the engine by providing false sensor data at the inputs120or providing false operational data to the primary channel132and the backup channel134of the thrust control channel130. When such an influence is detected, either by automated aircraft systems, or by a pilot or ground crew monitoring aircraft operations, the pilot can switch the controls from the thrust control channel130to the drag control channel110.

The drag control channel110is housed independently of the thrust control channel130, and includes multiple hard coded engine operation points. Each of the hard coded engine operational points corresponds to a single engine operational mode. Due to the hardware nature of the drag control channel110, digital intervention in the operational outputs to the engine effectors150from the cyber-security intrusion is not possible while the aircraft10is operating. By way of example, the drag control channel150can be a field programmable gate array (FPGA) with physical set states of each transistor within the FPGA. Further examples can use any similar hardware architecture to lock in the effector outputs from the drag control channel110.

Encoded within the drag control channel110are distinct nominal settings for each of the engine operation modes. The nominal settings are a pre-defined set of engine effector parameters to generate engine thrust at the desired engine operational mode under nominal conditions. As is understood, however, various external elements, and internal elements can impact the actual thrust produced as well as the effect of the produced thrust. With continued reference toFIG. 2,FIG. 3illustrates an engine operational mode chart for the drag control channel.

The engine operational mode chart300is illustrated with engine thrust as the vertical axis, and velocity of the aircraft as the horizontal axis. As stated previously, the drag control channel110includes six pre-programed nominal thrust outputs310. At each thrust output310, an engine operational curve320defines a window of operations within the desired engine operational mode, with the leftmost point332of each window330being the lowest velocity within the given window330and the rightmost point334of each window330being the highest velocity within the given window330. A center point336of each window330is the ideal velocity for operations within the operational mode310. In alternative systems, the ideal point of operation may not be at the exact center of the window330, and the operation curve320may not be a parabola as in the example ofFIG. 3.

In a practical flight, conditions are not nominal. As a result, the actual velocity with nominal drag controls will be either to the left or right of the center point336. In order to control the engine utilizing the drag controls, the pilot is able to engage, disengage, or alter various drag producing and reducing components across the aircraft10, thereby adjusting the velocity and ensuring that the velocity remains within the window330and as close to the center point336as possible. By way of example, the various drag producing components can include speed brakes, landing gear, sideslip (yaw), flaps, spoilers, g-load and the like. In some examples, the pilot can engage any given drag producing or reducing component individually to impact the drag in a desired manner. In alternative embodiments, it is possible for a general drag control to be implemented, allowing the pilot to command an increased or decreased drag causing a controller to apply controls across the various drag producing or reducing components in order to implement the command.

With continued reference to the system illustrated inFIGS. 1-3,FIG. 4illustrates a process400for operating an aircraft when a cyber-intrusion into a FADEC is detected. Initially the aircraft is operating in a thrust control mode in an “Operate in Thrust Control Mode” step410. The thrust control mode is any conventional thrust control of the aircraft engine(s). When a cyber-intrusion is detected in a “Detect Cyber Intrusion” step420, the pilot is notified, allowing the pilot to transition the engine controls from the thrust control channel of the engine controller to the drag control channel in a “Transition to Drag Control” step430. In alternative examples, the pilot can detect the cyber intrusion when the aircraft begins providing incorrect thrust responses to any given input command from the pilot, and can enter the transition step430.

Once the engine controller has switched to the drag control channel, the pilot sets a desired operational mode of the aircraft, causing the drag control channel to output hardwired engine settings for a nominal thrust of the desired operational mode. Once this has occurred, the pilot maintains the aircraft within the velocity window of the operational mode, by adjusting the drag of any number of drag producing or reducing components across the airframe in an “Adjust Drag to Maintain Aircraft Within Desired Operational Window” step440.

While controlling the engine via the drag control channel, the pilot can further alter the operational mode, and transition to the new operational mode. By way of example, if the airplane is currently in cruise mode, and approaching the landing site, the pilot can switch the drag control channel to approach mode. When such a transition occurs, the engine thrust settings output by the drag control channel switch to the nominal thrust settings for the new operational mode, and drag control resumes as described above.