Gulfstream G650ER Aileron Control System PDF

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL AILERON CONTROL — SYSTEM DESCRIPTION 1. General A. Description The aileron control system provides electrical and mechanical control of ailerons, monitoring and annunciation. The aileron system is part of the Fly-By-Wire (FBW) Primary Flight Control System...

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL AILERON CONTROL — SYSTEM DESCRIPTION 1. General A. Description The aileron control system provides electrical and mechanical control of ailerons, monitoring and annunciation. The aileron system is part of the Fly-By-Wire (FBW) Primary Flight Control System (PFCS). Ailerons and spoilers are located on rear beam of each wing. Spoilers assist ailerons in roll control. See Figure 1. During flight, aircraft longitudinal (roll) control is accomplished by movement of ailerons and spoilers. In addition, spoilers provided speed brake and ground spoiler functions. Spoiler operation is described in detail in the spoiler system description and its related subsystems. See Spoiler Control System, 27-60-00, System Description for more information on the spoilers. Control wheel movement sends command data to the Flight Control Computers (FCCs). The FCCs process data and send command data to Remote Electronic Units (REUs) located near each flight control surface. The REUs control hydraulic actuators located on outer wing trailing edges. The electronically controlled actuators provide power for aileron surface movement. Aileron deflection is 11° ±1° down and 19° ±1° up. 2. Subsystems Aileron Interface and Control, 27-11-00, System Description Aileron Cockpit Sensors, 27-12-00, System Description Aileron Hydraulic Actuation, 27-13-00, System Description Aileron System Electronics, 27-15-00, System Description Aileron Autopilot System, 27-16-00, System Description 3. Subsystem Details A. Aileron Interface and Control Conventional control wheels control the aircraft roll. The control wheels are mechanically linked during normal operation so they always move together. If a jam occurs with one control wheel, either pilot may override the other by exceeding and maintaining the breakaway force. Each control wheel is connected by control cables to its associated control module located below the cockpit floor. Control modules contain the following: Mechanical linkages Feel and centering units Electric motors An override mechanism RVDT position sensors The RVDTs provide commanded position data to the FCCs and Backup Flight Control Unit (BFCU). The FCCs send control data on Bidirectional ARINC 429 (BD429) digital data buses to REUs located at each actuator. The REUs command hydraulic actuators that move aileron surfaces. B. Aileron Cockpit Sensors Aileron movement is detected by five RVDT sensors, referred to as an RVDT cluster. The sensors are contained within a metal housing on top of the control module. The RVDT sensors translate mechanical movement into electronic data that is sent to the FCCs. The FCCs and BFCU provide excitation signals to the RVDT sensors and receive voltage signals back. The voltage change is proportional to the inceptor displacement and indicates the 27-10-00 Page 1 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL commanded position. When changes occur, the FCCs or BFCU command the REUs to energize the hydraulic controlled actuators and move flight surfaces to the commanded position. Sensors provide data to the following: FCCs BFCU Autopilot (AP) system Flight data recorder NOTE: The BFCU commands are ignored by the REUs unless there has been a total failure of both FCCs. C. Aileron Hydraulic Actuation Hydraulic actuation is driven by the FCCs. The FCCs provide position control data to aileron REUs. The REUs control hydraulic manifold output to the actuators in order to control aileron surface movement. The left and right hydraulic system, powered by the engine-driven pumps, provide hydraulic power to the manifolds. Ailerons are controlled by the following two separate and independent actuators: EHSA - Outboard actuator EBHA - Inboard actuator In the EHSA system the REU is mounted directly to the hydraulic actuator manifold. The EBHA actuator has an EHSA-type hydraulic part, combined with a local Motor Control Electronics (MCE). The MCE drives the hydraulic cylinder / piston in backup mode. The MCE is mounted directly to the electrical backup hydraulic manifold. EBHA actuator is installed between the EBHA and EHSA REUs. The EBHA actuator has the following dual power source: Hydraulic Electric The EBHA has an hydraulic cylinder / piston assembly and the following two hydraulic manifolds: EB HA D. Aileron System Electronics Control columns provide command position inputs to FCCs and BFCU using RVDT sensors. The sensors are contained within a metal housing on top of the control module. The FCCs sends control data on BD429 digital data buses to REUs located at each actuator. The REUs control hydraulic actuators that move aileron surfaces. The REUs provide position loop closure and actuator monitoring. For integrity control, each REU has two dissimilar hardware lanes, one for command and one for monitoring. E. Aileron Autopilot System The AP system has two servo actuators and two motors. The AP servo is attached to the aileron and elevator control module. One motor is attached to each column / wheel assembly. A mechanical interconnect allows either motor to drive the movement of both controls. This arrangement allows continuous operation if one side becomes jammed. The AP inputs are supplied through an electric AP servo motor that connects to the flight control mechanical input sector. The AP servo motor is mounted in each control module. The servos move 27-10-00 Page 2 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL the columns and wheels. One servo moves the column, another servo moves the wheel. Either pilot may override the AP system with sufficient wheel force to override the servo and disconnect the AP. The pilot side servo motor is controlled by Automatic Flight Control System (AFCS) 1 located in Modular Avionics Unit (MAU) No. 1. The copilot side motor is controlled by AFCS 2 in MAU No. 2. The servo motors are used to directly move the control wheels. There is no direct signal from the AFCS system to the FCC for aircraft control. Instead, the motors control the aircraft by moving the controls in the same manner as the flightcrew in manual control. This method has the benefit of providing the flightcrew visual feedback of what the AFCS system is doing to control the aircraft. 4. Operational Summary A. Aileron Control The FBW PFCS includes aileron control. Ailerons are controlled by pilot / copilot commands. The FCCs apply control laws and send the pilot / copilot commands as digital control data to the REUs located near the control surfaces. The REUs command hydraulic actuators that move the flight control surfaces. A control wheel is attached to each control column. The pilot / copilot controls roll by turning the control wheel in the direction of desired roll; counterclockwise to roll left, clockwise to roll right. Total control wheel travel is ±60°. (1) Aileron Roll Ailerons, flight spoilers and the aileron trim switch provide aircraft roll control during normal operating conditions. The aircraft roll command is initiated when either control wheel in the cockpit is rotated counterclockwise or clockwise. The motion is converted by the control module assembly into an electronic signal and transferred to the FCCs. The FCCs send the signal through BD429 data buses to the REUs in the wing. The REUs control the hydraulic actuators that move the ailerons and flight spoilers. The FCC signal enables the correct combination of aileron and flight spoiler positions to achieve the desired input roll rate. The ailerons, which move in opposite directions, together with the two flight spoilers on the downward moving wing, supply the necessary aerodynamic rolling force to roll the aircraft. The flight spoilers do not move on the opposite wing. The two flight spoiler panels rise together when the corresponding aileron reaches 0.5° aileron trailing edge up. As the aileron moves back down to its neutral position, the flight spoilers also move down until they are flush with the wing upper surface. (2) Yaw Damper The RUDDER (yaw) trim switches on the trim control panel are directly read by the FCC for the electronic trim function. Yaw damping is controlled by the FCCs using control laws. The usual tendency of an aircraft to yaw away from the direction of roll (adverse yaw) is offset by the following two actions: The aerodynamic drag of the raised flight spoilers on the inside of a turn, combined with The turn coordination supplied by automatic rudder inputs with the yaw damper operating (3) Trim Control Panel The trim control panel is located on the pedestal. Roll trim is accomplished electronically using a switch located on the trim control panel. The switch shall be selected down to enable electronic signals to be sent to the FCCs. A single roll trim actuator is mounted in the pilot side aileron and elevator control module and is used for normal lateral trim control. The actuator contains an internal RVDT sensor that 27-10-00 Page 3 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL measures its position. The RVDT receives an excitation signal (voltage) from the FCCs and returns a voltage to the FCCs that is proportional to the commanded trim position. The voltage change indicates the position command. The FCC send the RVDT signal to the displays. The trim actuator rotates the feel spring mechanism ground point and hence biases the aileron RVDT clusters. The FCC detects the bias in the RVDT signal and sends it to the aileron REU. In the event of a trim actuator malfunction, the ROLL MOTOR CONTROL switch on the trim control panel on the pedestal, can be depressed. The button illuminates OFF, disconnects the trim actuator power and signals the FCC to accept discrete signals from the roll trim switches in the trim control panel. (4) Autopilot When the AP is engaged, it supplies aircraft roll control. The AP inputs are supplied through an electric servo motor that connects to the FCC. 27-10-00 Page 4 August 15/14