Lecture+3-ADF+&+NDB (1).ppt

8/9/2019 Lecture+3-ADF+&+NDB (1).ppt

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By: Zuliana Ismail , 2010


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At the end of this lecture, thestudent should be able to:

Explain how Automatic Direction Finder(ADF) and the Non-directional Beacons(NDB) works

Describe the purpose of ADF & NDB

Explain the adanta!es & disadanta!es

of ADF & NDB"


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INTRODUCTION TO NDB & ADF

Non Directional Beacon

Automatic Directional Finde


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De#nitionADFis stand for Automatic DirectionFinder

NDBis stand for Non Directional

Beacon

ADF & NDB is the one of the older t!"esof radio na#i$ation s!stemthat still in

use toda$"

%he$ still in use toda$ because of itssimplicit$"


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ADF & NDB E'uipmentsADF & NDB E'uipments

Non Directional Beacon (NDB) is usedin conunction with AutomaticDirection Finder (ADF)in the cockpit"

ADF e'uipments consists of ) ADFantenna (transmitter & receier)outside aircraft%s bod! *) an ADFindicator inside the coc"it"

NDB e'uipment onl$ consist of$round NDB antennalocated nearthe airport (air#eld area)"

ADF determines the direction to


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ADF & NDB E'uipmentADF & NDB E'uipment

Ground NDB stations is the

Tall antenna located near

the airfield

ADF antenna outside

aircraft s !odyADF indicator inside

the coc"#it


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%he purpose of ADF+NDB is to proide aidfor aircraft nai!ation b$ "ro#ide bearin$information of aircraft location to theairport" (aircraft direction or headin! to the

airport in de!rees(an!le))

,,Bearin! the an!le which measured in aclockwise direction"

NDB bearin!s proide a consistent methodfor de#nin! paths aircraft can .$" NDB cande#ne /airwa$s/ in the sk$"


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01A2 has assi!ned 'o( Fre)uenc!*'F+ and edium Fre)uenc! *F+band for NDB

0t is within *33 4 563 789"8oweer most of NDB e'uipments arefound operatin! within fre'uenc$ band

of -../0-0 123


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NDB station radiates a non/directional

si$nal in all directions around its antenna(transmitter)"

:tation identi#cation code(1allsi!n) in the

form orse Code is also transmitted b$ theNDB"

An ADF selector in aircraft (ill tune toNDB%s fre)uenc! in order to search its

si$nalsAfter NDB call si$n is identi4ed thedirection of aircraft in B5ARIN6 to theNDB station (ill be indicated

ADF indicator in the cock it will dis la the

8ow ADF & NDB works


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%he uses of NDB

;sed for F F?2@ NDB or 82@0N>%2 NDB when maintainin! airwa$ centre-lines"

;sed for en-route nai!ational bearin!

;sed for 82 s$stem beforelandin!"

;sed as markers for an Instrument

'andin$ 7!stem *0


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F F?2@ or 82@0N>%2 NDB station

Flying From

Homing To


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En-?oute Nai!ation

Aircraft must maintain their headin! usin!the Automatic Direction Findin! (ADF) in thecockpit"

ilot must alwa$s watch the relatie bearin!

indicator to maintain the airwa$ center line"


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NDB also can used as the marers forInstrument 'andin$ 7!stem *I'7+a""roach

%his t$pe of NDB is also known as


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Adanta!es of NDB

NDB si!nal can be receied at lowaltitudes"

%his is because NDB si!nal is based on

surface wae propa!ation (si!nal notlimited to line of si!htC )"

NDB also can be used as the Back-;ps$stem" For example durin! no si!nal

!ien b$ the 8F 2mni-directional?an!e (2?) s$stem"

NDB s$stem onl$ re'uires low cost for

their maintenances"


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Disadanta!es of NDB


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Interference 59ect 4interference occurs if

an ADF receies two or more si!nalsradiated b$ NDB"

Thunderstorm 59ect 4 %hunderstormhae er$ powerful dischar!es of staticelectricit$ that can interrupt the NDB si!nal"Needle of ADF indicator sometimes pointstoward the storm"

ountain 59ect 4 @ountain areas cancause re.ections and diractions and leadto the error direction readin! b$ ADF"


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Ni$ht 59ect 4


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%he accurac$ of NDB is +- 6 de!reefor approach and +- 3 for en-route"

%he accurac$ of an NDB at an$ !ientime is diGcult to determine whenconsiderin! all the factors creatin!error"


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Exercises

Lecture+3-ADF+&+NDB (1).ppt

Documents

Transcript of Lecture+3-ADF+&+NDB (1).ppt