Marker Systems PDF

1 Chapter 2 MARKER SYSTEMS  2 Introduction The main purpose of the Marker Beacon system is to indicate the pilot that the airplane is passing over a particular geographical position i.e.  Points along an Air Route  Points...

1 Chapter 2 MARKER SYSTEMS  2 Introduction The main purpose of the Marker Beacon system is to indicate the pilot that the airplane is passing over a particular geographical position i.e.  Points along an Air Route  Points along an Instrument Landing Path  3 Learning Outcomes  Ground Signals of Marker Beacon System  Airport Lighting Indicators  Airborne Marker Beacon System  Marker System Interface  4 Marker Beacon System Mostly markers are used on final approach to the runway and are generally categorised into  Outer Marker (OM)  Middle Marker (MM)  Inner Marker (IM)  5 Markers at Changi Airport  6 Ground Signals of Marker Beacon System MARKER DISTANCE TONE CODE LIGHT FROM ON RUNWAY 75 MHz THRESHOLD CARRIER OM 4 nm ─── BLUE 400 Hz MM 3500 ft ─ ─ ─ AMBER 1300 Hz IM 250 ft WHITE 3000 Hz  7 Maker Operation  The pilot is requested to enter a holding pattern using the outer marker beacon  Once on the approach course with Localizer and Glideslope, the aircraft will cross the marker beacons in sequence as the aircraft descends  The aircraft, now within visual range of the runway and on direct course for it, is flown to a landing  8 OM RUNWAY MM IM TOP VIEW LOCALIZER TX GLIDESLOPE TX BLUE AMBER WHITE LIGHT LIGHT LIGHT SIDE 3000 ft GLIDESLOPE TX VIEW LOCALIZER TX 3500 ft 4 to 7 nm Marker Beacon Operation 9  10 RUNWAY CENTRE LINE Too High RUNWAY Slightly High On Glide Path Slightly Low ON GLIDESLOPE Too Low Glideslope Indicators  11 Airway marker or Fan marker  Airway marker transmits a high-pitched (3000 Hz) identification signal in the form of repeated dots and/or dashes  Fan markers are usually located within airways and their aerial systems are arranged to radiate narrow vertical fan-shaped beam  12 Airway marker or Fan marker  Fan markers are received in the aircraft on two separate marker receivers when the aircraft is over the reporting point: 1) A high-pitched coded signal delivered to pilot’s headset 2) A light flashes on the marker receiver indicator panel  13 FAN BEAM 10 nm AIRWAY Airway Marker  14 Example 2-1  Singapore airport has outer marker placed at 4 nm from the runway, if an aircraft is at a height of 0.2 nm on the marker, Find its angle of approach? tan  Angle of approch  Aircraft height Mar ker dis tan ce  0.2  1 Angle of approch  tan    2.8 0  4   15 Airport Lighting Indictors  Runway Visual Range (RVR) must be at least 1200 ft when the pilot begins his Category II approach  A Category II approach requires an airplane whose Category II equipment has been certified, in operation  In Category II airport equipment lighting Lights (LTS) are classified according to their functions i.e.  16 Sequenced Flashing LTS Approach LTS Runway Edge LTS Touchdown Zone LTS Runway Centreline LTS  17 Airport Lighting Indictors  Sequenced Flashing Lights cause an apparent movement of the light toward the runway  Approach Lights, which constitute a visible extension of the runway, these are designed so that the pilot can judge his position and altitude before touchdown  Runway Edge Lights shows the available width of the runway for landing, and extends to full length of the runway  18 Airport Lighting Indictors  Touchdown Zone lights shows the touch down area for the aircraft, generally these lights are spread for about first 3000 ft of the runway  Runway Centreline Lights extends to full length of the runway  LOCALIZER TX 19 1000 ft Runway Centre line LTS GLIDESLOPE TX 400 ft Touchdown Zone LTS 1000 ft Runway Edge LTS 1000 ft Approach LTS Sequenced Flashing LTS 2000 ft  20 Sequenced Flashing Lights 21  22 Example 2-2  A 10 kW television transmitter is at a distance of 10 nm from the airport marker, what is the power density at the marker? Transmiter power Power density  4  dis tan ce 2 10 10 3   8 W / nm 2 4 10 2  23 Airborne Marker Beacon System  Aircraft marker beacon receiver system consists of 75 MHz filter RF amplifier and Detector 3-audio filters to discriminate audio tones  The audio AC (about 6 volts) is used to light an indicator light  If the audio tone is 400 Hz, it lights a blue outer marker light, shown on the indicator panel  24  If it is a 1300 Hz tone, it lights an amber middle marker light  If it is a 3000 Hz tone, it lights a white marker/airways marker light  These marker beacon system is turned on when the airplane electrical buses are energized, and the applicable MKR BCN circuit breaker is closed  Outer and middle markers are associated with an instrument landing system  25 MARKER BEACON RECEIVER AUDIO OUTPUT 75 MHz AUDIO to FILTER AMPLIFIER INTERPHONE RF AMP and 3000 Hz DETECTOR FILTER AMP INNER 1300 Hz FILTER AMP MIDDLE 400 Hz FILTER AMP OUTER Airborne Marker Beacon System 26  27 Marker System Interface  Once the aircraft reaches near the airport, pilot selects Instrumentation Landing System (ILS) mode by changing the frequency on the control unit  Marker beacon antenna will receive beacon signals and the receiver can identify the beacon through the light indication on the instrumentation panel  Flight Warning Computer (FWC) monitors the conditions of the Marker system and issue a warning SIGNAL to the pilot in case of any failure  CAP F/O 28 FLIGHT DISPLAY 1 FLIGHT DISPLAY 2 Marker Interface IM IM NAVIGATION MM MM NAVIGATION DISPLAY 1 DISPLAY 2 DME-1 DME-2 OM OM DME-1 DME-2 VOR/VOR CONTROL UNIT VOR/VOR MARKER BEACON FMC1 MARKER BEACON RECEIVER FMC2 RECEIVER AUDIO MARKER INTEGRATING MARKER ANTENNA SYSTEM ANTENNA  29 Marker Interface for Boeing Aircraft  30 The End