精密进近seminarie1006_precisionapproaches

PrecisionApproachesThepurposeofanIFRapproachPrecisionapproaches–Non-PrecisionApproaches•Anapproachwhereyouhavemeansofmeasuringdeviationofthedesiredverticalthedesiredverticalprofile,isa‘precisionapproach’.Example:ILSPrecisionapproaches–Non-PrecisionApproaches•Anyotherapproachisa‘non-precisionapproach’.Examples:VORapproach,NDBapproach,LOC(G/Sout)approachInstrument–Visual•Flyanapproachbasedoninstruments•TransitiontovisualsegmentforlandingPositiontheaircraftforlandingPositiontheaircraftforlanding•“Straight-in”•“Circle-to-land”Instrument–VisualToseetheRunway:•Ceilinghighenough(outofclouds)•VisibilitygoodenoughObstacleClearance•Howlowcanyougo?PrecisionApproachMinima•Duringaprecisionapproach,youfollowthedescentprofileuntilyoureachthe‘DecisionAltitude’orDA.Thisiswhereyoudecidetocontinueorgo-around.around.•TheDAcanbeanaltitude‘AboveMeanSeaLevel’,AMSL,basedontheQNHandreadontheBAROaltimeter,ora‘RadioAltitude’orRA,readontheRadioAltimeter,indicatingyouractualaltitudeabovetheground,dependingontheprocedureflown.Non-PrecisionApproachMinima•Duringanon-precisionapproach,thelowestaltitudeyoucansafelydescendtoiscalledthe‘MinimumDescentAltitude’orMDA.YoucanflylevelattheMDAuntilflylevelattheMDAuntilreachingyour‘MissedApproachPoint’orMAPt.Thisiswhereyoudecidetocontinueorgo-around.•MDAwillbeanaltitude‘AboveMeanSeaLevel’orAMSL.BasedupontheQNHandreadontheBAROaltimeter.ApproachMinima•Ifyoudon’tseetheRWYattheminima:GO-Around!(decisionaltitude…)•Areusedtodeterminewhetheryoucanflyanapproach•TellyouhowlowyoucansafelygowithoutseeingtheRWY•Assurego-aroundobstacleclearance,evenintheeventofamissedapproachwithenginefailureApproachMinima•Arepublishedforeveryapproach,consideringvisibility,obstacleclearanceandaircraftperformancelimitations.•Arefoundontheapproachcharts•Aredifferentforeveryapproachandmayvary•Aredifferentforeveryapproachandmayvarydependingthecurrentconditions.Thesecanbe:–AircraftequipmentandType(Category)–Airportequipmentand/orlocalprocedures–AircrewqualificationAircraftCategoryEveryaircrafttypehasoneofthefollowingapproachcategoriesbasedonaverageapproachspeed:•CategoryA:Speed91kts.(eg.C172,PA28,...)•CategoryB:Speed91kts121kts.(eg.KingAir)•CategoryB:Speed91kts121kts.(eg.KingAir)•CategoryC:Speed121kts141kts.(eg.B737,A320,...)•CategoryD:Speed141kts166kts.(eg.B747,A340,...)•CategoryE:Speed166kts.(eg.Concorde)Asapilot,youshouldknowunderwhichcategoryyouraircrafttypeisclassified.Example:Straight-inMDAforthisapproachis720ftMSLforallaircraftcategories.ForB737(CatC)yourequireatleast1800mofRVR.Forastraight-inCATIILS,theDAwillbe819ftMSL.MinimumRVRis600m.WiththeApproachLightingSystem(ALS)out,yourequireRVRof1000m.PrecisionApproachMinimaILS•CATI(CATIILSisthedefaultILSapproach)RVR550m–DA200ftAAL(AboveAerodromeLevel(abovethelandingthreshold))•CATII•CATIIRVR350m–DH100ftRA•CATIIIRVR200m–DH50ftRA»CATIIIa(guidanceuntiltouchdown)»CATIIIb(guidanceduringroll-out)»CATIIIc(guidanceuntiltaxi-intothegate)MostcommercialaircraftandairlinesareCATIIIaLowVisibilityProcedures(LVP)mustbeinforcetoconductCATIIorCATIIIapproaches.LVPareputinforcebylocalATC.Thiscomprisesadifferentsetofgeneralrulesforoperations.However,practiceCATII-IIIapporachesmaybeperformedbyaircrewwhenLVPnotinforce.InthatcaseATCmustbeadvised.Theywillthenshedresponsibilitybystatingequipmentreliabilityisnotguaranteed.MeteorologicalconditionsApproachBanprocedure:•Anapproachmaybecommencedregardlessoftheweatherconditionsatthetime,however…•TocontinuepasttheOuterMarkerorequivalentposition,thereportedvisibilitymustbeequalorbetterthanthoserequiredontheapproachchartforthecurrentconditions.•OnlythevisibilityisrequiredtoflyanapproachbeyondtheOuterMarkeror•OnlythevisibilityisrequiredtoflyanapproachbeyondtheOuterMarkerorequivalent.•OncepasttheOMorequivalentposition,theapproachmaybecontinueddowntoDA/MDAregardlessofweatherreportsreceived.•Forcircle-to-landapproachesyoumusthavetheceilingandthevisibilityatoraboveminimatocontinuepasttheoutermarkerorequivalent.MeteorologicalconditionsVisibility–RVR:Visibility:Thevisibilityisreportedbyacertifiedobserveratacertainobservatory.ThisisusuallytheTWR.Theycanestimatethevisibilityaccordingtoknownlandmarksinview.(eg.Buildings,hilltops,towns,etc…)RVR:RunwayVisualRangeRVR:RunwayVisualRangeThisisanelectronicallymeasuredvisibilitybytransmissiometersalongtherunway.Itisspecialisedequipmentthatisnotinstalledatallairports.Youcancheckthe10-9chartstoseeisitisavailable.RVRwillbereportedinMETAR,ATISandonTWRfrequency.Example:R25L/P1500N:RVRRwy25L=morethan1500m,tendency‘Nochange’R27/0600U:RVRRwy27=600m,tendency‘Up’R32/0350D:RVRRwy32=350m,tendency‘Down’Underthesameconditions,RVRisgenerallyhigherthanVIS.Therefore,RVRwillsometimesallowpilotstoflyapproacheswhentheVISisbelowtheminima.EBCI22006KT0800FGOVC00113/12Q1026NOSIGCanyouflythestraight-inILS?CanyouflyitwhenApproachLightingSystemisout?EBCI19002KT3000OVC008BKN04013/12Q1026NOSIGYes,youneedtheVIS,nottheceiling.No,inthiscasetheRVRrequiredis1000mYes,OVC008=800ftaboveairfield.800ft+Q1026NOSIGCanyouflythecircletolandinB737?Canyouflythecircletolan