A320 Flight Controls

27.00 CONTENTS\n\n27.10 DESCRIPTION\n- GENERAL .............................................. 1\n- ARCHITECTURE ....................................... 5\n\n27.20 NORMAL LAW\n- GENERAL ................................................ 1\n- PITCH CONTROL ........................................ 1\n- LATERAL CONTROL ..................................... 6\n- LOAD ALLEVATION FUNCTION (A320 ONLY) .... 7\n- SIDESLIP TARGET ....................................... 8\n\n27.30 RECONFIGURATION CONTROL LAWS\n- GENERAL ................................................ 1\n- FLIGHT CONTROLS LAW RECONFIGURATION. 2\n- ALTERNATE LAW ....................................... 3\n- ALTERNATE LAW WITHOUT REDUCED PROTECTION. 6\n- DIRECT LAW .............................................. 6\n- ABNORMAL ATTITUDE LAWS .......................... 7\n- MECHANICAL BACKUP ................................. 7\n\n27.40 CONTROLS AND INDICATORS\n- PEDESTAL ................................................ 1\n- LATERAL CONSOLES .................................. 3\n- GLARESHIELD .......................................... 4\n- OVERHEAD PANEL ..................................... 5\n- SIDESTICK INDICATIONS ON PFD ............ 8\n- ECAM F/CTL PAGE ................................... 9\n- ECAM WHEEL PAGE ................................. 11\n- WARNINGS AND CAUTIONS ...................... 12\n- MEMO DISPLAY ......................................... 14\n\n27.50 FLAPS AND SLATS\n- DESCRIPTION .............................................. 1\n- CONTROLS AND INDICATORS ....................... 5\n- WARNINGS AND CAUTIONS .......................... 8\n\n27.60 ELECTRICAL SUPPLY .................................. 1\n GENERAL\n\nThe fly-by-wire system was designed and certified to render the new generation of aircraft even more safe, cost effective, and pleasant to fly.\n\nBASIC PRINCIPLE\n\nFlight control surfaces are all :\n- Electrically-controlled, and\n- Hydraulically-activated.\nThe stabilizer and rudder can also be mechanically-controlled.\nPilots use sidesticks to fly the aircraft in pitch and roll (and in yaw, indirectly, through turn coordination).\nComputers interpret pilot input and move the flight control surfaces, as necessary, to follow their orders.\nR However, when in normal law, regardless of the pilot's input, the computers will prevent excessive maneuvers and exceedance of the safe envelope in pitch and roll axis.\nR However, as on conventional aircraft, the rudder has no such protection.\n\nA/P COMPUTER\n\n FEEDBACK\n\n COMPUTER ORDER\n \n SIDE STICK F/CTL COMPUTER\n PILOT'S COMMAND \n\n FEEDBACK\n\n SURFACE\n\n RESPONSE\n CONTROL SURFACES\n\nThe flight controls are electrically or mechanically controlled as follows :\n\nPitch axis\nElevator = Electrical\nStabilizer = Electrical for normal or alternate control. Mechanical for manual trim control.\n\nRoll axis\nAilerons = Electrical\nSpoilers = Electrical\n\nYaw axis\nRudder = Mechanical, however control for yaw damping, turn coordination and trim is electrical.\n\nSpeed brakes\nSpeed brakes = Electrical\n\nNote : All surfaces are hydraulically actuated.\n FLIGHT CONTROLS 1.27.10 P 3 DESCRIPTION SEQ 001 REV 23 COCKPIT CONTROLS - Each pilot has a sidestick controller with which to exercise manual control of pitch and roll. These are on their respective lateral consoles. The two sidestick controllers are not coupled mechanically, and they send separate sets of signals to the flight control computers. - Two pairs of pedals, which are rigidly interconnected, give the pilot mechanical control of the rudder. - The pilots control speed brakes with a lever on the center pedestal. - The pilots use mechanically interconnected handwheels on each side of the center pedestal to control the trimmable horizontal stabilizer. - The pilots use a single switch on the center pedestal to set the rudder trim. - There is no manual switch for trimming the ailerons. COMPUTERS Seven flight control computers process pilot and autopilot inputs according to normal, alternate, or direct flight control laws. The computers are : 2 ELACs (Elevator Aileron Computer) For : Normal elevator and stabilizer control. Aileron control. 3 SECs (Spoilers Elevator Computer) For : Spoilers control. Standby elevator and stabilizer control. 2 FACs (Flight Augmentation Computer) For : Electrical rudder control. In addition 2 FCDC Flight Control Data Concentrators (FCDC) acquire data from the ELACs and SECs and send it to the electronic instrument system (EIS) and the centralized fault display system (CFDS). SIMU F.P.S.3 UP for training only STD 1.3.1 FLIGHT CONTROLS 1.27.10 P 4 DESCRIPTION SEQ 001 REV 23 MECH LINK RUDDER SIDESTICK PEDALS TRIM FAC ELAC SEC FCDC HEADING DISPLAYS ELEVATORS AILERS YAW RATE ORDER RUDDER SIDE TRIM RUDDER REINFORCING FMGC ADIRU ACCELERO LGC1U EIS ABN LAW HYDRAULIC JACKS SIMU F.P.S.3 UP for training only STD 1.3.1 FLIGHT CONTROLS 1.27.10 P 5 DESCRIPTION SEQ 100 REV 24 ARCHITECTURE GENERAL ARCHITECTURE FOR INFO SPD-BRK GND-SPLR SPD-BRK GND-SPLR ROLL ROLL L. AIL B G ELAC 1 2 SEC 2 1 1 3 3 3 3 1 1 2 1 2 3 1 1 2 1 2 FAC 1 2 B G Y G SFCC 1 THS HYDRAULIC SFCC 2 SFCC 2 MOTORS ELEVATORS MECH CONT R. ELEV B G 1 1 2 2 1 2 ELAC G Y 2 Y G 1 FAC 1 2 2 TRV LIM B Y RUDDER G Y G YAW DAMPER ACTUATOR B G Y G 1 FAC 1 2 FAC 2 Y indicates the hydraulic power source (green, blue, or yellow) for each servo control. SIMU F.P.S.3 UP for training only STD 1.3.1 Two elevators and the Trimmable Horizontal Stabilizer (THS) control the aircraft in pitch. The maximum elevator deflection is 30° nose up, and 17° nose down. The maximum THS deflection is 13.5° nose up, and 4° nose down.\n\nELECTRICAL CONTROL\n\n- In normal operations, ELAC2 controls the elevators and the horizontal stabilizer, and the green and yellow hydraulic jacks drive the left and right elevator surfaces respectively. The THS is driven by N° 1 of three electric motors.\n- If a failure occurs in ELAC2, or in the associated hydraulic systems, or with the hydraulic jacks, the system shifts pitch control to ELAC1. ELAC1 then controls the elevators via the blue hydraulic jacks and controls the THS via the N° 2 electric motor.\n- If neither ELAC1 nor ELAC2 is available, the system shifts pitch control either to SEC1 or to SEC2, (depending on the status of the associated circuits), and to THS motor N° 2 or N° 3.\nPage 8, below, describes how the actuators are reconfigured in case of failure.\n\nMECHANICAL CONTROL\n\nMechanical control of the THS is available from the pitch trim wheel at any time, if either the green or yellow hydraulic system is functioning.\nMechanical control from the pitch trim wheel has priority over electrical control. Elevators\n\n- Two electrically-controlled hydraulic servojacks drive each elevator. Each servojack has three control modes:\n. Active: The jack position is electrically-controlled.\n. Damping: The jack follows surface movement.\n. Centering: The jack is hydraulically retained in the neutral position.\n- In normal operation:\n . One jack is in active mode.\n . The other jack is in damping mode.\n . Some maneuvers cause the second jack to become active.\n- If the active servojack fails, the damped one becomes active, and the failed jack is automatically switched to the damping mode.\nR If neither jack is being controlled electrically, both are automatically switched to centering mode.\nR If neither jack is being controlled hydraulically, both are automatically switched to damping mode.\n- If one elevator fails, the deflection of the remaining elevator is limited in order to avoid putting excessive asymmetric loads on the horizontal tailplane or rear fuselage.\n\nStabilizer\n\n- A screwjack, driven by two hydraulic motors, drives the stabilizer. The two hydraulic motors are controlled by:\n . One of three electric motors, or\n . The mechanical trim wheel. PITCH CONTROL - SCHEMATIC\n\nMechanical Trim\n\nELAC 1\n\nSEC 1\n\nSEC 2\n\nTHS ACTUATOR\n\nELEV\n\nTHS\n\nSIMU F.P.S.3 UP for training only STD 1.3.1 ROLL CONTROL\nOne aileron and four spoilers on each wing control the aircraft about the roll axis.\nThe maximum deflection of the ailerons is 25°.\nThe ailerons extend 5° down when the flaps are extended (aileron droop).\nThe maximum deflection of the spoilers is 35°.\n\nELECTRIC CONTROL\n- The ELAC 1 normally controls the ailerons.\nIf ELAC1 fails, the system automatically transfers aileron control to ELAC2.\nIf both ELACs fail, the ailerons revert to the damping mode.\n- SEC3 controls the N° 2 spoilers, SEC1 the N° 3 and 4 spoilers, and SEC2 the N° 5 spoilers.\nIf a SEC fails, the spoilers it controls are automatically retracted.\n\nACTUATION\nAilerons\nEach aileron has two electrically controlled hydraulic servojacks.\nOne of these servojacks per aileron operates at a time.\nEach servojack has two control modes:\nActive : Jack position is controlled electrically\nDamping : Jack follows surface movement.\n\nSIMU F.P.S.3 UP\nfor training only\nSTD 1.3.1