Gulfstream G650ER Elevator System Sensors and Indication PDF

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL ELEVATOR SYSTEM SENSORS AND INDICATION — SYSTEM DESCRIPTION 1. General A. Description Force sensors (strain gauges) are installed on each column assembly to detect pilot action to override the servos. Each Flight Control Computer (FCC) interfaces with one...

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL ELEVATOR SYSTEM SENSORS AND INDICATION — SYSTEM DESCRIPTION 1. General A. Description Force sensors (strain gauges) are installed on each column assembly to detect pilot action to override the servos. Each Flight Control Computer (FCC) interfaces with one sensor on each column. Detected force changes at the pilot and copilot stations are provided to the FCCs. The FCCs send the demanded position data to the elevator Remote Electronics Units (REUs). Each elevator control surface LVDTs provides surface position data to the associated REU. The REU compares the demanded ram position against the actual ram position as provided by the ram LVDT. The difference between the demanded and actual ram position becomes the control error. The REU then commands the Electro-Hydraulic Servo Valve (EHSV) proportional to the ram error until the control error is reduced to zero. The EHSA manifold contains the EHSV position LVDT, hydraulic supply and return pressure sensors and the compensator position LVDT. The EHSA hydraulic actuator contains a single channel LVDT that provides position sensing information to the REU. There are no other electrical components in the EHSA actuator. The EB manifold contains the EHSV position LVDT, hydraulic supply and return pressure sensors and the hydraulic temperature sensor. The HA manifold contains the compensator position LVDT and the retract and extend cylinder pressure sensors that monitor hydraulic pressure on both sides of the actuator piston. The EBHA contains a two channel LVDT that provides position sensing information. One channel is connected to the REU and the other to the Motor Control Electronics (MCE). There are no other electrical components in the EBHA actuator. 2. Component Location COMPONENT ATA QTY PER A/C LOCATION Elevator LVDT 27-34-01 2 Horizontal stabilizer 3. Component Details A. Elevator LVDT The elevator surface LVDT is installed as part of the elevator actuation system between the elevator surfaces and the rear spar of the horizontal stabilizer. The purpose of the LVDT is to protect against a main ram LVDT disconnect failure mode. Two elevator surface LVDT sensors are installed at the following locations (see Figure 1): Left elevator surface - Outboard edge Right elevator surface - Outboard edge The following two type of actuators are used: EBHA - Two channel LVDT EHSA - Single channel LVDT The two channel EBHA LVDT provides position sensing data as follows: One channel provides data to the REU One channel provides data to the MCE 27-34-00 Page 1 August 15/14 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL The single channel EHSA LVDT provides position sensing data to the REU. The REU provides the sensing data to the FCCs. If a main ram LVDT becomes disconnected, the FCCs determine which actuator (EHSA or EBHA) is operating correctly. 4. Controls and Indications A. Circuit Breakers The system is protected by the following circuit breakers: NOMENCLATURE PANEL LOCATION POWER SOURCE L ELEV HA LEER A8 L ESS 28VDC L ELEV EBHA PRI REER B3 UPS 28VDC R ELEV EBHA PRI REER B4 UPS 28VDC L ELEV EBHA SEC REER B8 UPS 28VDC R ELEV HA REER B8 R ESS 28VDC R ELEV EBHA SEC REER C8 UPS 28VDC L ELEV EBHA PWR N/A EBHA PDB (tail compartment) EBHA BUS 28VDC R ELEV EBHA PWR N/A EBHA PDB (tail compartment) EBHA BUS 28VDC B. CAS Messages The CAS messages for the system are shown in the following table: MESSAGE COLOR MESSAGE DESCRIPTION Stall Reference Speed Increase Blue Stall protection speed increased because of wing anti-ice fail and possible ice accretion on wings. Verify increased landing reference speed and increased landing distance. AP Trim Fail Blue AP trim has failed. AP Inhibit-Stall Blue AP inhibit-stall is active. Pitch Trim Nose Down Limit Blue Pitch trim at nose down limit. Adjust pitch trim as necessary. Pitch Trim Nose Up Limit Blue Pitch trim at nose up limit. Adjust pitch trim as necessary. Stick Shaker 1-2 Fail Blue Stick shaker 1 and 2 have failed. AP Inhibit-Manual Trim Active Blue Go Around Pitch Blue Go around pitch is active. Stall Protection Active Amber Angle of Attack (AOA) limiting mode is active. Adjust flight condition as necessary. 27-34-00 Page 2 August 15/14 AP inhibit-manual trim is active. GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL MESSAGE COLOR MESSAGE DESCRIPTION Stall Protection Unavailable Amber AOA data unavailable or flight control mode other than normal. Continue flight within flight envelope limitations, minimum airspeed Vref. Retrim Left Wing Down Amber Retrim left wing down. Retrim Right Wing Down Amber Retrim right wing down. L-R Elevator Fail Amber Both REUs failed or loss of elevator command to both elevators. Continue flight within flight envelope limitations. Attempt FLT CTRL RESET. Elevator Single Actuator Amber Single elevator actuator failed. Notify maintenance for corrective action. Attempt FLT CTRL RESET. Vertical Coupling Data Invalid Amber Pitch Authority Limit Amber Pitch axis flight control surfaces approaching maximum displacement. Adjust flight condition as necessary. Amber Pilot and copilot pitch control column positions are different. Continue flight within flight envelope limitations. Aircraft pitch response with respect to control column input may be reduced. Pitch Control Miscompare NOTE: Vertical coupling data is invalid. The FCC status information required by the flightcrew is shown on the main displays as CAS messages and synoptic page data. 5. Operation A. Elevator System Sensors and Indication The main ram LVDT measures the position of the power control unit main ram for the purpose of positional closed-loop control of the main ram. The EHSV main control valve controls the main ram velocity and direction of motion. The EHSV uses an LVDT to measure the second stage control valve position for the purpose of failure monitoring. The compensator has an LVDT to monitor the position of the reservoir piston during periodic maintenance Built-In Test (BIT) tests. These tests measure leakage rates of the EHSA and ensure the compensator is functioning properly. The EBHA reservoir has an LVDT to monitor the position of the reservoir piston during periodic maintenance BIT tests. These tests measure leakage rates of the EBHA and ensure the reservoir is functioning properly. 27-34-00 Page 3 August 15/14