Gulfstream G650ER Flap Actuation System PDF

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL FLAP ACTUATION — SYSTEM DESCRIPTION 1. General A. Description The flap actuation system is powered by the left hydraulic system. The left hydraulic system provides hydraulic power to the flap Hydraulic Control Module (HCM). See Figure 1. The HCM consists o...

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL FLAP ACTUATION — SYSTEM DESCRIPTION 1. General A. Description The flap actuation system is powered by the left hydraulic system. The left hydraulic system provides hydraulic power to the flap Hydraulic Control Module (HCM). See Figure 1. The HCM consists of a solenoid operated Shut-off Valve (SOV) and an Electro-Hydraulic Servo Valve (EHSV). The HCM is the control interface between the electrical output of the Flap Electronic Control unit (FECU) and the hydraulic input for the Power Drive Unit (PDU). The EHSV ports the hydraulic power to extend or retract the flaps to the PDU. The PDU is the control and power conversion element of the flap hydraulic actuation system. The PDU consists of an hydraulic motor and gearbox. The PDU is mounted transverse to the top of the torque box at FS 579, WL 48 and right BL 1. 2. Component Location COMPONENT ATA QTY PER A/C LOCATION Flap power drive unit 27-53-01 1 Main wheel well Flap torque shaft 27-53-05 16 Wing rear beam Flap pillow block 27-53-07 12 Wing rear beam Flap actuator (inboard) 27-53-09 2 Wing rear beam Flap actuator (outboard) 27-53-09 2 Wing rear beam Flap hydraulic control module 27-55-05 1 Main landing gear wheel well 3. Component Details A. Flap Power Drive Unit The flap PDU is located in the main landing gear wheel well. It contains a gearbox and a hydraulic motor. The PDU converts hydraulic power into mechanical action to activate the flap system. The PDU is connected to the flap inboard and outboard ballscrew actuators via torque shafts and pillow blocks. The PDU simultaneously drives the flap actuators in the commanded direction on both the left and right wings. This ensures synchronous flap panel operation. B. Flap Torque Shaft The flap torque shafts are located on the wing rear beam and are numbered from inboard to outboard. There are eight flap torque shafts on each wing rear beam. The flap torque shafts consist of aluminum tubes riveted to fixed and floating universal joint couplings at opposite ends. Extending from the free ends of the universal joint couplings are internally splined driveshafts. The splined shafts are connected to the flap pillow blocks and flap actuators. The flap torque shafts are bolted at one end and float in the spline connection at the other end to allow for axial float. To accommodate installation, one end of the driveshaft is collapsible. The collapsible portion of the driveshaft is retained by two cross-bolts. C. Flap Pillow Block The flap pillow blocks (bearing supports) are located on the rear beam of the wing and are located in between flap torque shafts. There are six pillow blocks in each torque shaft drive line. Pillow blocks are numbered from inboard to outboard. Pillow blocks have splined shaft on both ends that 27-53-00 Page 1 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL mate to the splined end fittings on the torque shafts, two ball bearings and an aluminum housing. The pillow block bearings are packed with grease and sealed to prevent FOD and moisture ingress. D. Flap Actuator (Inboard) The flap actuators are located on the wing rear beam. The flap actuators extend and retract the two trailing edge flaps by converting rotary input torque into linear motion and force. The inboard and outboard flap actuators are essentially identical with exception of the ballscrew, due to the different stroke requirements of the actuators. The outboard flap actuators also have a resolver installed in the outboard side of the actuator housing. Outboard actuators are distinguished from inboard actuators by a dual channel sensor (resolver) mounted on the actuator housing. The resolver is used for system position and asymmetry detection. Both outboard and inboard flap actuators are gimbal mounted to a fixed structure on the rear spar of the wing. The actuators drive the flap surface carriage with the ballscrew driving a translating nut. The translating nut is gimbal mounted to the flap carriage. Actuators are grease lubricated and vented to prevent corrosion. Flap actuators perform the following three basic functions: Conversion of high-speed rotary motion at the input shaft to low-speed linear motion at the translating nut Irreversibility that the translating nut cannot be back driven in normal operation and / or torque shaft or actuator disconnect system failure mode System overload protection by limiting maximum force that each actuator applies To provide irreversibility, the flap actuators incorporate a skewed roller brake with a ratchet plate to handle compressive ballscrew loads. The ratchet plate is configured such that the brake ratchets, while rotating a plain thrust bearing for flap extension. To react to tension loads on the ballscrew, the actuator is designed with a simple drag device to provide actuator irreversibility. This device is active whenever the tension loads are on the ballscrew, regardless of whether the system is extending or retracting. The device consists of a steel rotating plate, sliding against a nylon brake disk that is bonded into the housing. If a flap actuation system jam or other condition occurs that results in increased flap loading, the force limiting function in each actuator provides overload protection of flap actuation system components and supporting structure by limiting the maximum actuator output load. The force limiter is a mechanical device housed in the flap actuator. The force limiter mechanically senses the ballscrew load and engages when an overload condition is detected. Engagement of the force limiting device stalls the actuator. A stalled actuator trips one of the system safety monitors and the complete flap actuation system is disengaged. For flap retraction, the ratchet pawls ground the ratchet plate and force the skewed roller assembly to rotate. The skewed roller assembly provides braking torque proportional to the ballscrew load. This braking torque is greater than the corresponding torque generated by the lead of the ballscrew. The braking torque divided by the ballscrew back driving torque is typically referred to as no back brake gain. The no back is configured such that each no back brake is sufficient to hold position in the event that the other actuator in the same flap panel has dormant failed no back brake. To reduce the probability of the no back dormant failure, the no back brake is designed with two ratchet pawls, springs and different materials preclude common mode failure. In addition, ratchet pawls are spaced such that they click into the ratchet plate at different times. This facilitates an audible in-service check on the no back pawl functionality. 27-53-00 Page 2 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL E. Flap Actuator (Outboard) See Flap Actuator (Inboard) component details for information on the outboard flap actuator. F. Flap Hydraulic Control Module The flap HCM is located in the main landing gear wheel well. The HCM receives command inputs from the FECU to extend or retract the flaps. The HCM controls the hydraulic flow to the EHSV through the solenoid operated SOV. The HCM controls the position and rate of the flaps through the EHSV. 4. Controls and Indications A. Circuit Breakers The system is protected by the following circuit breakers: NOMENCLATURE PANEL LOCATION POWER SOURCE FLAP MON REER A8 R ESS 28VDC FLAP CMD LEER A10 L ESS 28VDC B. CAS Messages The CAS messages for the system are shown in the following table: MESSAGE COLOR MESSAGE DESCRIPTION Flap Maintenance Required Blue System has detected a fault but is still operational. Flap Rigging Complete Blue Indicates to maintenance that rigging is complete. Flaps Asymmetry Amber Flap position asymmetry detected. Flaps have stopped moving toward selected position. Plan for landing with reduced flap setting. Flap Command Invalid Amber Flap handle is placed or jammed in an invalid position. Reposition flap handle to valid position. Amber No surface movement when flap handle is commanded or surface movement in opposite direction or uncommanded flap surface movement. Place handle to previous position, reduce airspeed and reset handle to desired position. If flap operation not recovered, plan for landing with reduced flap setting. Flaps Failed NOTE: The FCC status information required by the flightcrew is shown on the main displays as CAS messages and synoptic page data. 5. Operation A. Flap Actuation The pilot / copilot initiate flap deployment commands using the flap control module. The FECU calculates the valid command and provides solenoid and EHSV commands to the HCM. The FECU calculates the valid command and provides solenoid and EHSV commands to the HCM. The torque shafts transfer the torque generated by the PDU to the flap actuators and drive the flaps to the commanded position. 27-53-00 Page 3 August 15/14