STALL BARRIER SYSTEM.pdf

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL STALL BARRIER SYSTEM — SYSTEM DESCRIPTION 1. General A. Description The stall barrier system does not use conventional stall actuators. The Flight Control Computers (FCCs) contain control laws that provide Angle of Attack (AOA) limiting. During normal oper...

GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL STALL BARRIER SYSTEM — SYSTEM DESCRIPTION 1. General A. Description The stall barrier system does not use conventional stall actuators. The Flight Control Computers (FCCs) contain control laws that provide Angle of Attack (AOA) limiting. During normal operation, the embedded control laws limit the allowable AOA to prevent exceeding the maximum AOA. During degraded operation or during extreme maneuvers, it may be possible to exceed the maximum AOA. At that time, the stick shaker is activated. Stick shakers are used to warn the pilot of an approaching stall. There is one stick shaker motor for each control column (pilot / copilot). Each stick shaker motor is driven by a separate FCC. The stick shakers are installed at the lower end of each control column below the floor mounts. The FCC provides discrete signals that control the stick shakers. The stick shaker motors shake the control column during an approaching stall, before the maximum AOA is exceeded. 2. Component Location COMPONENT ATA QTY PER A/C LOCATION Stick shaker motor 27-37-01 2 Lower end of each column below the floor 3. Component Details A. Stick Shaker Motor The stick shaker motors are located below the column mount on the column / wheel assembly. The FCC controls activation of the shakers by internally switching the 28 Vdc power to the motor. The 28 Vdc power for the stick shaker motor enters the FCC and passes through internal switches controlled by the FCC software. The pilot stick shaker motor is powered by the left essential dc bus. The copilot stick shaker motor is powered by the right main dc bus. See Figure 1. 4. Controls and Indications A. Circuit Breakers The system is protected by the following circuit breakers: NOMENCLATURE PANEL LOCATION POWER SOURCE SHAKER 1 LEER B11 L ESS DC Bus SHAKER 2 REER C9 R MAIN DC Bus B. CAS Messages The CAS messages for the system are shown in the following table: MESSAGE COLOR MESSAGE DESCRIPTION Stall Reference Speed Increase Amber 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. Stick Shaker 1-2 Fail Blue Stick shaker 1 and 2 have failed. 27-37-00 Page 1 June 30/15 GULFSTREAM G650ER SYSTEM DESCRIPTION MANUAL MESSAGE COLOR MESSAGE DESCRIPTION Stall Protection Active Amber AOA limiting mode is active. Adjust flight condition as necessary. Stall Protection Unavailable Amber AOA data unavailable or flight control mode other than normal. Continue flight within flight envelope limitations, minimum airspeed velocity reference. 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. Stall Barrier System When the AOA is trending toward 85% of maximum, the FCC control laws enters AOA limiting. Prolonged flight in AOA limiting is not prohibited. While in AOA limiting, pitch control may appear sluggish and unresponsive to pitch-up control inputs. At maximum aft displacement of the control column, maximum AOA will be achieved. Should maximum AOA be exceeded, the stick shaker activates, warning of a potential aerodynamic stall condition. The AOA limiting is not available for the following modes: Direct Backup Alternate A CAS message alerts the flightcrew to the AOA condition. If AOA data is available, the stick shaker will activate at 0.85 normalized AOA. However, pilot control will not be augmented to prevent an aerodynamic stall. 27-37-00 Page 2 June 30/15