A320前轮转弯系统介绍及维护一车间李辉一、背景介绍Thesteeringsystemusesthegreenoryellowhydraulicsystemtooperateasteeringactuatingcylinder,whichchangesthedirectionoftheNLGwheels.JetblueAirbusperformsalowpassfortheLGBtowerforanosegearinspection,andasyoucanseethenosegearisina90-degreeposition.Followingtheflyby,theaircraftspentthenext2hoursflyingoverthePacificOceanjustoffLongBeachburningfuelbeforedivertingtoLAXforanemergencylanding,whichhappilywasasuccesfulonewithoutinjuries.JetBlue292BUR-JFKmakesitsemergencylandingatLAX.Thefrontgearwasturnedperpendiculartotherunwaycausingthesparksandsmoke.LTEInternationalAirwaysA320-214在着陆滑跑过程中因前轮转弯系统故障，导致偏离跑道，前轮陷入跑道旁边的草地。二、系统介绍SYSTEMOVERVIEWThesteeringsystemreceiveshydraulicpressureinthefollowingconditions:ThesteeringsystemiscontrolledbytheBSCU,whichreceivesorderfrom:前轮转弯角度限制HandwheelsThesteeringangleislimitedasafunctionoftheaircraftspeed.RudderpedalsPEDALSDISC按钮可在以下情况脱开脚蹬对前轮转弯的控制：－Duringruddergroundcheck.－Therunwayisicy.Pilotcandisconnectthecontrolthroughthepedalsfromthesteeringcontrol.NoseWheelSteeringServo-Control(6GC)enhancedtypeNoseWheelSteeringServo-Control(6GC)classictypeNoseWheelSteeringServo-Control(6GC)NoseWheelSteeringServo-Control(6GC)maincomponents对于传统型A320飞机，由于前轮转弯系统使用的是来自前起落架舱门关闭油路的绿系统液压压力，因此，在飞机执行重力放起落架的程序后，前轮转弯系统将无法工作，需用拖车拖回停机坪。NoseWheelSteeringFeedbackSensor(3GC,4GC)NoseWheelSteeringFeedbackSensor(3GC,4GC)Thecontrolchannelactsontheservovalveasafunctionofthedifferenceinpositionbetweenthehandwheel(inthecockpit)andthewheels.Themonitoringchanneldeliversinasimilarmannerasignalwhichrepresentsthepositionoftheslidevalveintheservovalve.swivelselectorvalvesteeringactuatingcylinder三、维护要点1、关于3GC、4GC的维护AMM手册关于前轮转弯0位的调节提供了9种程序，其主要区别就是采用了不同的基准参考数据和3GC、4GC调节工具：基准数据：1－RudderTrimAngleasReference2－NLGCenteringCamsasReference3－Nose-WheelAlignmentTool调节工具：ForP/NC24763000：F26630200或M46196-100＋F26792000ForP/NE21336000：F26792000AMM32-51-00-820-00x前起落架支撑主结构与旋转筒之间有一个前轮定中的目视指示标记，上下刻度标志线对齐的时候为飞机支线滑行（前轮转弯0位）。注意：此标记仅仅作为维护中的快速参考标记，在对转弯系统的调节中不作为前轮定中的参考标准，AMM无此