ils

1. AIRBUS A 320
INSTRUMENT LANDING
SYSTEM
(INCLUDING CAT II / CAT IIIA)

2. /USPR/ - ETS, HYDERABAD 2
• LANDING IS AN IMPORTANT PHASE OF THE
FLIGHT.
• WHEN THE AIRCRAFT IS APPROACHING
THE AIRPORT, THE AIRCRAFT TAKES A
PATH IN LINE WITH THE RUNWAY AND FROM
A CERTAIN DISTANCE BEGINS TO DESCEND
UNTIL IT TOUCHES GROUND AT A POINT
NEAR THE RUNWAY THRESHOLD.
• WHEN THE VISIBILITY IS GOOD, WHETHER
IN A DAY OR NIGHT, THE LANDING IS
CARRIED OUT BY VISUAL OBSERVATION OF
RUNWAY MARKINGS AND RUNWAY LIGHTS.

3. /USPR/ - ETS, HYDERABAD 3
• THE LANDING IS THEN PERFORMED UNDER
VISUAL FLIGHT RULES (VFR) CONDITIONS.
• USUALLY THIS IS DONE WHEN THERE IS A
HORIZONTAL VISIBILITY OF ABOUT 5 KM
OR MORE AND THE VERTICAL VISIBILITY
OF 300 METERS OR MORE.
• WHEN THESE CONDITIONS ARE NOT
SATISFIED, THE LANDING IS DONE UNDER
INSTRUMENT FLIGHT RULES (IFR)
CONDITIONS.

5. /USPR/ - ETS, HYDERABAD 5
• SPECIAL RADIO AIDS ARE LOCATED IN THE
AIRPORTS TO ENABLE THE AIRCRAFT TO
EXECUTE LANDINGS IN IFR CONDITIONS
UNDER BAD VISIBILITY.
• SUCH AIDS GIVE THE AIRCRAFT ITS EXACT
POSITION IN RELATION TO A DESIRED PATH
OF DESCENT.
• THIS MEANS THAT THE GUIDANCE
REGARDING THE DEVIATION OF THE
AIRCRAFT IN THE HORIZONTAL AND
VERTICAL PLANES IS GIVEN.

6. /USPR/ - ETS, HYDERABAD 6
• THE GUIDANCE GIVEN ARE LEFT / RIGHT
GUIDANCE WHICH HELPS THE AIRCRAFT
TO FOLLOW THE CENTERLINE OF THE
RUNWAY AND UP / DOWN GUIDANCE TO
FOLLOW A PARTICULAR GLIDE PATH FOR
SMOOTH TOUCH DOWN.
• THE INSTRUMENT LANDING SYSTEM
COMPRISES OF THE UNITS LOCALISER
AND GLIDE SLOPE.
• THE LOCALISER DEFINES THE CENTERLINE
OF THE RUNWAY AND THE GLIDESLOPE
DEFINES THE TOUCH DOWN ANGLE.
• THE INTERSECTION OF THESE TWO GIVES
THE APPROACH PATH.

7. /USPR/ - ETS, HYDERABAD 7

8. /USPR/ - ETS, HYDERABAD 8

9. /USPR/ - ETS, HYDERABAD 9
• THE LOCALISER OPERATES IN THE VHF BAND
(108 - 110 MHZ.) AND RADIATES TWO LOBES,
ONE WITH A PREDOMINANT MODULATION OF
90 HZ AND THE OTHER WITH A PREDOMINANT
MODULATION OF 150 HZ.
• ALONG THE CENTERLINE OF THE RUNWAY,
BOTH THE SIGNALS ARE EQUAL.
• THE LOCALISER TRANSMITTER AND ANTENNA
ARE LOCATED AT ABOUT 1000 FEET AT THE
OTHER END OF THE RUNWAY.

10. /USPR/ - ETS, HYDERABAD 10
• THE GLIDESLOPE OPERATES IN THE UHF BAND
(329 - 335 MHZ.) AND THE OPERATING PRINCIPLE
IS SAME AS LOCALISER, BUT GIVES VERTICAL
GUIDANCE.
• THE TRANSMITTER AND ANTENNA ARE LOCATED
AT THE SIDE OF THE RUNWAY AT ABOUT 1000
FEET FROM THE TOUCHDOWN POINT.
• TO FIND OUT THE RANGE FROM THE RUNWAY,
MARKER INSTALLATIONS ARE USED.
• MARKERS RADIATE FAN SHAPED VERTICAL
RADIATION PATTERN UPWARDS IN 75 MHZ
FREQUENCY WITH IDENTIFICATION SIGNALS
MODULATED IN IT.

11. /USPR/ - ETS, HYDERABAD 11
NEED FOR HIGHER CATEGORIES OF
INSTRUMENT LANDING SYSTEMS
• THE INSTRUMENT LANDING SYSTEMS INSTALLED
IN SOME OF THE AIRPORTS IN INDIA MEET THE
CATEGORY I LEVEL REQUIREMENTS.
• IN BAD WEATHER CONDITIONS, WHEN RVR IS
BELOW 600 METERS, AIRCRAFT CANNOT LAND OR
TAKE OFF USING SUCH AIRPORTS.
• HENCE, IT IS NECESSARY TO DEVELOP THE
CAPABILITY TO OPERATE FLIGHTS IN ALL
WEATHER CONDITIONS.

12. /USPR/ - ETS, HYDERABAD 12
DIFFERENT ASPECTS
INVOLVED IN ILS ARE
• AIRBORNE EQUIPMENT
• AIRCRAFT MAINTENANCE
• NON VISUAL AIDS (ILS FACILITY)
• VISUAL AIDS (RUNWAY MARKINGS AND
LIGHTING SYSTEMS)
• AIRFIELD MAINTENANCE
• ATC PROCEDURES and
• FLIGHT CREW PROCEDURES

13. /USPR/ - ETS, HYDERABAD 13

14. /USPR/ - ETS, HYDERABAD 14

15. /USPR/ - ETS, HYDERABAD 15
CAT II DEFINITION
A PRECISION INSTRUMENT
APPROACH AND LANDING WITH
- DECISION HEIGHT
LOWER THAN 200 FEET BUT NOT
LOWER THAN 100 FEET AND
- RUNWAY VISUAL RANGE
NOT LESS THAN 350 METERS

16. /USPR/ - ETS, HYDERABAD 16

17. /USPR/ - ETS, HYDERABAD 17
CAT III A DEFINITION
A PRECISION INSTRUMENT APPROACH AND
LANDING WITH
• A DECISION HEIGHT
LOWER THAN 100 FEET BUT NOT LOWER
THAN 50 FEET AND
• RUNWAY VISUAL RANGE
NOT LESS THAN 200 METERS

18. /USPR/ - ETS, HYDERABAD 18

19. /USPR/ - ETS, HYDERABAD 19
CAT III B DEFINITION
A PRECISION INSTRUMENT APPROACH AND
LANDING WITH
• NO DECISION HEIGHT OR DECISION HEIGHT
LOWER THAN 50 FEET and
• RUNWAY VISUAL RANGE LESS THAN 200
METERS BUT NOT LESS THAN 50 METERS

20. /USPR/ - ETS, HYDERABAD 20
CAT III C DEFINITION
A PRECISION INSTRUMENT
APPROACH AND LANDING WITH
• NO DECISION HEIGHT and
• NO RUNWAY VISUAL RANGE
LIMITATIONS

21. /USPR/ - ETS, HYDERABAD 21
AUTOMATIC LANDING SYSTEM
• AUTOMATIC LANDING SYSTEM IS
ONLY AN EQUIPMENT (OR GROUP OF
EQUIPMENT) PROVIDING AUTO
CONTROL OF THE AIRCRAFT DURING
APPROACH AND LANDING AND IT IS
NOT RELATED TO WEATHER
CONDITIONS.

22. /USPR/ - ETS, HYDERABAD 22
CAT II HAS OPTIONAL
AUTOLAND
• CAT II WEATHER MINIMA IS
ESTABLISHED TO PROVIDE
SUFFICIENT VISUAL REFERENCE AT
DH TO PERMIT A MANUAL LANDING.
• HOWEVER, AUTOMATIC LANDING
CAN ALSO BE DONE IN CAT II

23. /USPR/ - ETS, HYDERABAD 23
IN CAT III, AUTO LANDING IS
A MUST
• IN CAT III, WEATHER MINIMA DO NOT
PROVIDE SUFFICIENT VISUAL
REFERENCES TO ALLOW MANUAL
LANDING.
• THE MINIMA ONLY PERMIT THE PILOT TO
DECIDE TO LAND IN THE TOUCH DOWN
ZONE AND TO ENSURE SAFETY DURING
ROLL OUT.
• AS CAT III DOES NOT PROVIDE A
SUFFICIENT VISUAL REFERENCE,
AUTOMATIC LANDING SYSTEM IS
MANDATORY.

24. /USPR/ - ETS, HYDERABAD 24
DECISION HEIGHT
• DECISION HEIGHT IS THE SPECIFIED
HEIGHT IN THE PRECISION APPROACH, AT
WHICH A GO AROUND MUST BE INITIATED
UNLESS ADEQUATE VISUAL REFERENCE
HAS BEEN ESTABLISHED TO CONTINUE
THE APPROACH.
• DH IS MEASURED BY MEANS OF RADIO
ALTIMETER FOR CAT II / CAT III
OPERATIONS

25. /USPR/ - ETS, HYDERABAD 25

26. /USPR/ - ETS, HYDERABAD 26
VISUAL REFERENCE
• THE REQUIRED VISUAL REFERENCE
MEANS, THE VISUAL AIDS OF THE SECTION
OF THE RUNWAY OR OF THE APPROACH
AREA, that means,
• FOR CAT II / CAT III OPERATIONS, A PILOT
MAY NOT CONTINUE APPROACH BELOW
DH, UNLESS A VISUAL REFERENCE
CONTAINING NOT LESS THAN THREE
SEGMENT OF THE ANY CATEGORY OF THE
LIGHTS IS OBTAINED.

27. /USPR/ - ETS, HYDERABAD 27
DECESION HEIGHT
• FOR CAT II OPERATIONS THE DH IS IN
BETWEEN 200 FEET AND 100 FEET.
• FOR CAT III OPERATIONS WITH DH,
THE DH IS IN BETWEEN 100 FEET AND
50 FEET.
• NORMALLY, THE DH MINIMUM IS
MENTIONED FOR REFERENCE

28. /USPR/ - ETS, HYDERABAD 28
ALERT HEIGHT
• ALERT HEIGHT IS THE HEIGHT
ABOVE THE RUNWAY, DEFINED FOR
CAT III OPERATIONS WITH FAIL
OPERATIONAL AUTOMATIC
LANDING SYSTEM.
• DH DEPENDS UPON VISIBILITY
CONDITIONS AND AH DEPENDS
UPON SERVICEABILITY OF
EQUIPMENT.

29. /USPR/ - ETS, HYDERABAD 29
ALERT HEIGHT
• ABOVE AH, A CAT III APPROACH WOULD
BE DISCONTINUED AND GO AROUND IS
INITIATED IF A FAILURE IS OCCURRED IN
ONE OF THE REDUNDANT PARTS OF THE
AUTOMATIC LANDING SYSTEM OR IN
THE RELEVANT GROUND EQUIPMENT.
• BELOW AH, APPROACH MAY BE
CONTINUED EXCEPT WHEN AUTO LAND
WARNING IS TRIGGERED

30. /USPR/ - ETS, HYDERABAD 30
FAIL OPERATIONAL AUTO
LANDING SYSTEM
• AN AUTOMATIC LANDING SYSTEM IS FAIL
OPERATIONAL, IF IN THE EVENT OF A
FAILURE BELOW ALERT HEIGHT, THE
REMAINING PART OF THE AUTOMATIC
LANDING SYSTEM ALLOWS THE AIRCRAFT
TO COMPLETE THE APPROACH, FLARE
AND LANDING
• IN AIRBUS A 320 AIRCRAFT, "CAT III DUAL"
IS FAIL OPERATIONAL LANDING SYSTEM.

31. /USPR/ - ETS, HYDERABAD 31
FAIL PASSIVE AUTO
LANDING SYSTEM
• IN THIS TYPE OF LANDING SYSTEM, IN THE EVENT
OF A FAILURE, THERE IS NO SIGNIFICANT
DEVIATION OF AIRCRAFT TRIM OR DEVIATION OF
FLIGHT PATH OR ATTITUDE, BUT THE LANDING IS
NOT COMPLETED AUTOMATICALLY.
• WITH THE FAIL PASSIVE AUTOMATIC LANDING
SYSTEM, THE PILOT ASSUMES CONTROL OF THE
AIRCRAFT AFTER A FAILURE.
• IN AIRBUS A 320 AIRCRAFT, "CAT III SINGLE" IS FAIL
PASSIVE AUTOMATIC LANDING SYSTEM.

32. /USPR/ - ETS, HYDERABAD 32
PROTECTION BY FMGC IN
A 320 AIRCRAFT
• BELOW 100 FEET RADIO ALTITUDE, THE
FMGC FREEZES THE LANDING CAPABILITY,
UNTIL LAND MODE IS DISENGAGED OR
BOTH AUTOPILOTS ARE OFF.
• THEREFORE, A FAILURE BELOW 100 FEET
DOES NOT CHANGE THE CATEGORY OF THE
LANDING SYSTEM

33. /USPR/ - ETS, HYDERABAD 33
RUNWAY VISUAL RANGE
• RVR IS THE RANGE OVER WHICH A PILOT
OF AN AIRCRAFT ON THE CENTERLINE OF
THE RUNWAY CAN SEE THE RUNWAY
SURFACE MARKINGS OR THE LIGHTS
DELINEATING THE RUNWAY OR
IDENTIFYING ITS CENTERLINE.
• CAT II / CAT III OPERATIONS REQUIRE
RAPIDLY UPDATED AND RELIABLE
REPORTS OF THE VISIBILITY CONDITIONS
WHICH A PILOT MAY EXPECT TO
ENCOUNTER IN THE TOUCHDOWN ZONE
AND ALONG THE RUNWAY.

34. /USPR/ - ETS, HYDERABAD 34
RUNWAY VISUAL RANGE
RVR

35. /USPR/ - ETS, HYDERABAD 35
SLANT VISUAL RANGE (SVR)
• RVR IS NOT SLANT VISUAL RANGE (SVR).
SVR IS THE RANGE OVER WHICH A PILOT
OF AN AIRCRAFT IN THE FINAL STAGES OF
APPROACH OR LANDING CAN SEE THE
MARKINGS OR THE LIGHT ON THE RUNWAY.
• SVR IS NOT MEASURED AS THE PILOT
HIMSELF CAN SEE FROM THE HEIGHT.

36. /USPR/ - ETS, HYDERABAD 36
SLANT VISUAL RANGE

37. /USPR/ - ETS, HYDERABAD 37

38. /USPR/ - ETS, HYDERABAD 38
TRANSMISSOMETERS
• RVR MEASUREMENTS ARE
MEASURED BY A SYSTEM OF
CALIBRATED TRANSMISSOMETERS
AND IT ACCOUNTS FOR THE EFFECTS
OF AMBIENT LIGHT AND THE
INTENSITY OF RUNWAY LIGHTS.

39. /USPR/ - ETS, HYDERABAD 39

40. /USPR/ - ETS, HYDERABAD 40
LOCATIONS OF
TRANSMISSOMETERS
• TRANSMISSOMETERS ARE STRATEGICALLY
LOCATED AND PROVIDE RVR MEASUREMENTS
ASSOCIATED WITH THREE BASIC PORTIONS OF
THE RUNWAY
• THE TOUCH DOWN ZONE (TDZ)
• THE MID RUNWAY PORTION (MID) AND
• THE ROLL OUT PORTION OR THE STOP END

41. /USPR/ - ETS, HYDERABAD 41
REQUIREMENTS OF RVRs
• FOR CAT II /CAT III A OPERATIONS
TOUCHDOWN ZONE RVR OR MID RVR
MEASUREMENT IS SUFFICIENT.
• BUT FOR CAT III B OPERATIONS, BOTH
TOUCHDOWN ZONE AND MID RVR ARE
MANDATORY AND ROLL OUT PORTION RVR
IS RECOMMENDATORY

42. /USPR/ - ETS, HYDERABAD 42
TRANSMISSOMETRS
INSTALLATION
• RVR DEFINITION CONSIDERS PILOT’S EYE
TO BE AT 15 FEET ABOVE THE RUNWAY
SURFACE. THE LIGHT PATH FROM THE
RUNWAY MARKINGS (AT 0 FEET) TO THE
PILOT’S EYE (15 FEET) HAS A MEAN HEIGHT
OF 7.5 FEET.
• HENCE, TRANSMISSIOMETERS ARE
LOCATED AT 6 TO 10 FEET HEIGHT ABOVE
THE RUNWAY.

43. /USPR/ - ETS, HYDERABAD 43
RUNWAY REQUIREMENTS
THE MARKINGS NECESSARY FOR CAT II / CAT
III OPERATIONS ARE
• RUNWAY CENTERLINE MARKINGS
• RUNWAY THRESHOLD MARKINGS
• TOUCHDOWN ZONE MARKINGS AND
• TAXI HOLDING POSITION MARKINGS
RUNWAY MARKINGS ARE WHITE IN COLOUR
TAXIWAY MARKINGS ARE YELLOW IN COLOUR

44. /USPR/ - ETS, HYDERABAD 44
VARIOUS LIGHTS INSTALLED
IN RUNWAYS
• RUNWAY THRESHOLD LIGHTS
• RUNWAY END LIGHTS
• RUNWAY EDGE LIGHTS
• RUNWAY CENTERLINE LIGHTS
• TOUCHDOWN ZONE LIGHTS
• APPROACH LIGHTS
• TAXIWAY CENTERLINE LIGHTS
• STOP BARS AND
• TAXI HOLDING POSITION LIGHTS

45. /USPR/ - ETS, HYDERABAD 45
INTERFERENCE TO ILS
SIGNALS
• ANY LARGE REFLECTING OBJECTS, INCLUDING
VEHICLES, AIRCRAFT AND FIXED STRUCTURES
WITHIN THE RADIATED SIGNAL COVERAGE, WILL
POTENTIALLY CAUSE INTERFERENCE TO ILS
SIGNALS.
• THE AREAS WITHIN WHICH DEGRADABLE
INTERFERENCE TO THE ILS SIGNALS OCCUR DUE
TO MOVEMENT ON THE GROUND IS DIVIDED INTO
TWO TYPES.
• ILS CRITICAL AREA AND ILS SENSITIVE AREA

46. /USPR/ - ETS, HYDERABAD 46

47. /USPR/ - ETS, HYDERABAD 47
CRITICAL AREAS
• IT IS AN AREA OF DEFINED DIMENSIONS
ABOUT THE LOCALISER AND THE GLIDEPATH
ANTENNAS WHERE VEHICLES, INCLUDING
AIRCRAFT, ARE EXCLUDED DURING ALL ILS
OPERATIONS
• THE CRITICAL AREA IS PROTECTED
BECAUSE THE PRESENCE OF VEHICLES AND
/ OR AIRCRAFT INSIDE THESE BOUNDARIES
WILL CAUSE UNACCEPTABLE DISTURBANCE
TO THE ILS SIGNALS IN SPACE.

48. /USPR/ - ETS, HYDERABAD 48
SENSITIVE AREAS
• IT IS AN AREA EXTENDING BEYOND THE
CRITICAL AREA WHERE THE PARKING AND /
OR MOVEMENT OF VEHICLES, INCLUDING
AIRCRAFT IS CONTROLLED TO PREVENT
THE POSSIBILITY OF UNACCEPTABLE
INTERFERENCE TO THE ILS SIGNALS
DURING ILS OPERATIONS.
• THE SIZE OF A SENSITIVE AREA DEPENDS
UPON A NUMBER OF FACTORS INCLUDING
THE TYPE OF ILS ANTENNA, THE
TOPOGRAPHY AND THE SIZE AND
ORIENTATION OF MOVING OBJECTS.

49. /USPR/ - ETS, HYDERABAD 49
BETTER ANTENNAS
• MODERN DESIGNS OF LOCALISER
AND GLIDESLOPE ANTENNAS CAN BE
VERY EFFECTIVE IN REDUCING THE
DISTURBANCE POSSIBILITIES AND
HENCE THE EXTENT OF SENSITIVE
AREAS.

50. /USPR/ - ETS, HYDERABAD 50

51. /USPR/ - ETS, HYDERABAD 51
AIRBUS A 320 INSTRUMENT LANDING
SYSTEM
• THE FUNCTION OF ILS IS TO MEASURE THE
DEVIATIONS BETWEEN AIRCRAFT FLIGHT PATH AND
– GLIDE SLOPE
– RUNWAY ALIGNMENT PLANE (LOCALISER)
• THE LOCALISER OPERATES IN THE FREQUENCY
RANGE FROM 108 MHz TO 111.95 MHz.
• THE GLIDE SLOPE OPERATES IN THE FREQUENCY
RANGE 328.6 MHz TO 335.4 MHz.
• THERE ARE TWO SIMILAR AND INDEPENDENT
SYSTEMS

52. /USPR/ - ETS, HYDERABAD 52
THE COMPONENTS AND THEIR
LOCATION
• ILS 1 RECEIVER 95 VU
• ILS 2 RECEIVER 96 VU
• LOCALISER ANTENNA 110 AL DOOR
• GLIDE SLOPE ANTENNA 110 AL DOOR
• EFIS CONTROL SECTION ILS PB (2)
• MASTER CAUTION LIGHTS
• AUDIO CONTROL PANELS
• RADIO MANAGEMENT PANELS
• MCDU 1 AND 2
• FMGC 1 AND 2
• FLIGHT WARNING COMPUTERS, DISPLAY MANAGEMENT
COMPUTERS AND DISPLAY UNITS
• CFDIU

53. /USPR/ - ETS, HYDERABAD 53

54. /USPR/ - ETS, HYDERABAD 54
ANTENNAS
• LOCALISER ANTENNA
– THE ANTENNA IS CAPABLE OF RECEIVING IN THE
FREQUENCY RANGE OF 108 TO 112 MHz.
– IT IS A FOLDED HALF LOOP TYPE DRIVEN BY
CAPACITIVE COUPLING
– IT HAS TWO RF CONNECTORS USED TO FEED BOTH
ILS RECEIVERS ON ONE SIDE.
• GLIDE SLOPE ANTENNA
– THE ANTENNA IS CAPABLE OF RECEIVING IN THE
FREQUENCY RANGE OF 329 TO 335 MHz.
– THE TYPE OF THE ANTENNA IS SAME AS LOCALISER
ANTENNA
– IT HAS TWO INDEPENDENT CONNECTORS TO
CONNECT TO BOTH THE ILS RECEIVERS.

55. /USPR/ - ETS, HYDERABAD 55

56. /USPR/ - ETS, HYDERABAD 56
ILS RECEIVER
• AT THE FACE OF THE RECIEVER, THERE
ARE THREE LEDs. THEY ARE ILS FAIL (RED),
ILS PASS (GREEN) AND DATA IN (RED) AND
A TEST SWITCH.
• ILS FAIL INDICATES INTERNAL FAILURE
• DATA IN INDICATES NO CONTROL INPUT OR
INCORRECT ARINC 429 INPUT FORMAT
• ILS PASS INDICATES THE SYSTEM IS O.K.
• BACK SIDE THERE ARE THREE
CONNECTORS FOR ATE INTERFACE,
SYSTEM INTERCONNECTIONS AND POWER
SUPPLY

57. /USPR/ - ETS, HYDERABAD 57

58. /USPR/ - ETS, HYDERABAD 58
INSIDE THE RECEIVER
• THE ILS RECEIVER INCLUDES
– A LOCALISER TUNER
– A GLIDE SLOPE TUNER
– A BITE MODULE
– AN ILS MODULE
– A CPU MODULE
– A CPU MONITOR MODULE
– A DATA INTERFACE MODULE AND
– POWER SUPPLY MODULES

59. /USPR/ - ETS, HYDERABAD 59

60. /USPR/ - ETS, HYDERABAD 60
LOCALISER TUNER
– IT RECEIVES AND DEMODULATES THE SIGNAL
FROM ONE OF THE 40 CHANNELS.
– IT INCLUDES A PRE SELECTOR
• TUNED TO SELECTED LOCALISER CHANNEL BY THE
TUNING VOLTAGE PROVIDED BY THE CPU MODULE
– MIXER
• SUBTRACTS THE LOCAL OSCILLATOR FREQUENCY FROM
THE PRESELECTOR LOCALISER SIGNAL TO PRODUCE
18.1 MHz IF SIGNAL.
– TWO IF AMPLIFIERS AND THE SECOND ONE IS A
THREE STAGE AMPLIFIER
– AN ENVELOPE DETECTOR, WHICH DETECTS THE
LOW FREQUENCY ENVELOPE OF THE RECEIVED
SIGNAL.

61. /USPR/ - ETS, HYDERABAD 61
GLIDE SLOPE TUNER
• IT RECEIVES AND DEMODULATES THE
SIGNALS FROM ONE OF THE 40 CHANNELS
AND COUPLED WITH THE LOCALISER
FREQUENCIES.
• IT HAS
– A PRESELECTOR
– A MIXER (IF IS 30.2 MHz)
– TWO IF AMPLIFIERS AND
– AN ENVELOPE DETECTOR

62. /USPR/ - ETS, HYDERABAD 62
BITE MODULE AND ILS MODULE
• BITE MODULE GENERATES 90 Hz AND
150 Hz TEST COMPOSITE SIGNALS
DURING THE TEST SEQUENCE.
• THE ILS MODULE PROCESSES THE
GLIDE SLOPE AND LOCALISER
COMPOSITE SIGNALS. ITS CIRCUITS
SEPARATE THE 90 Hz AND 150 Hz FROM
EACH COMPOSITE SIGNAL AND
GENERATES A DC VOLTAGE
PROPORTIONAL TO THE MODULATION
LEVEL OF EACH TONE.

63. /USPR/ - ETS, HYDERABAD 63
CPU MODULE AND CPU
MONITOR MODULE
• CPU MODULE PERFORMS THE PRIMARY CONTROL,
TIMING AND LOGIC COMPUTATIONS REQUIRED FOR
THE RECEIVER OPERATION (IT HAS A 80C85
MICROPROCESSOR)
• CPU MONITOR MODULE READS THE ANALOG
LOCALISER AND GLIDESLOPE TONES FROM THE ILS
MODULE, CONVERTS THEM INTO DIGITAL,
COMPUTES THE GLIDESLOPE AND LOCALISER
COURSE DEVIATION IN DDM AND COMPARES ITS
COMPUTATIONS WITH THE PRIMARY CPU
COMPUTATIONS TRANSMITTED ON THE ARINC 429
BUS.

64. /USPR/ - ETS, HYDERABAD 64
DATA INTERFACE AND POWER
SUPPLY MODULES
• DATA INTERFACE MODULE GIVES BOTHWAY ARINC 429
COMMUNICATION PATH BETWEEN RECEIVER, CONTROL
UNIT AND DISPLAY UNITS. IT ALSO RECEIVES THE
RECEIVER TUNING DATA AND CONTROL DISCRETES.
• THE POWER SUPPLY MODULE HAS TWO SUB MODULES.
– THE CONTROL MODULE WHICH HAS THE MAJOR RECTIFIER
ASSEMBLY AND
– OUTPUT MODULE WHICH DEVELOPES THE DC REGULATED
OUTPUTS FROM THE DC VOLTAGES SUPPLIED BY THE CONTROL
MODULE.
– IT DEVELOPS THE OUTPUTS + 5 VDC, +15 VDC, - 15 VDC AND +8
VDC
– A POWER MONITOR OUTPUT IS ALSO DEVELOPED AND APPLIED
TO A VOLTAGE CPMAPARATOR IN THE CPU MODULE.

65. /USPR/ - ETS, HYDERABAD 65

66. /USPR/ - ETS, HYDERABAD 66
AIRBUS A320 AUTO LANDING
SYSTEM
THERE ARE TWO TYPES OF “APPROACH”
AVAILABLE IN A 320
• ILS APPROACH: (LAND MODE):
APPROACH IS PERFORMED ON THE ILS
BEAM (GLIDESLOPE AND LOCALISER)
• FMS APPROACH: GUIDANCE IS
PERFORMED FROM A THEORETICAL
PATH COMPUTED BY FMGC

67. /USPR/ - ETS, HYDERABAD 67

68. /USPR/ - ETS, HYDERABAD 68
ILS APPROACH HAS THE
PRIORITY
• THE TYPE OF APPROACH IS SELECTED
THROUGH MCDU. THE SELECTION OF AN
ILS FREQUENCY ON RMP FORCES THE
SELECTION OF ILS APPROACH,
WHATEVER BE THE SELECTION MADE
ON MCDU
• ILS APPROACH CAN BE SELECTED IMPLICITLY
THROUGH FLIGHT PLAN DEFINITION OR
EXPLICITLY BY SELECTING A FREQUENCY AND
RUNWAY HEADING BY MEANS OF MCDU OR
RMP

69. /USPR/ - ETS, HYDERABAD 69
ILS APPROACH
• THE ILS MODE OF APPROACH PROVIDES
THE CAPTURE AND TRACK OF ILS BEAM
(LOC. AND GLIDE) AND ENSURES THE
FUNCTIONS ALIGNMENT, FLARE, AND
ROLL OUT
• ILS MODE IS AVAILABLE FOR THE AP
AND FD. IT ENABLES LANDINGS TO BE
PERFORMED FOR CAT III OPERATIONS
• THEREFORE, THE SELECTION OF LAND
MODE AUTHORIZES THE ENGAGEMENT
OF SECOND AP.

70. /USPR/ - ETS, HYDERABAD 70
ILS APPROACH
• THE ARMING OF LAND MODE BY APPR
PUSHBUTTON ON FCU ENABLES THE
LOC. AND GLIDE MODE TO BE ARMED IN
THE LATERAL AND LONGITUDINAL AXES.
• THE SUPPORT MODES ACTIVE IN THESE
AXES REMAIN ENGAGED UNTIL THE LOC
AND GLIDE BEAMS ARE CAPTURED.
• SWITCHING TO LOC. CPT AND G/S. CPT
MODES OCCURS WHEN THE CAPTURE
CONDITIONS ARE MET.

71. /USPR/ - ETS, HYDERABAD 71
ILS APPROACH
• WHEN THE AIRCRAFT IS STABILIZED ON
THE LOC. AND GLIDE BEAMS, THE LOC.
TRACK AND GLIDE TRACK MODES ARE
ACTIVATED.
• THE AP / FD GUIDES THE AIRCRAFT
ALONG THE ILS BEAM TO 30 FEET.
• AT THIS ALTITUDE, THE LAND MODE
PROVIDES THE ALIGNMENT ON THE
RUNWAY CENTERLINE ON THE YAW AXIS
AND FLARE ON THE PITCH AXIS.

72. /USPR/ - ETS, HYDERABAD 72
ILS APPROACH
• THE LAND TRACK MODE HAS TWO SUB
MODES, ALIGN AND ROLL OUT
• ALIGN MODE ENGAGES PROVIDED BOTH
FACS ARE OPERATIONAL. BELOW 100
FEET, LOSS OF FACS DOES NOT CAUSE
AP / FD DISENGAGEMENT OR LOSS OF
LAND TRACK MODE.
• ROLL OUT SUB MODE IS ENGAGED AT
TOUCHDOWN AND PROVIDES GUIDANCE
ON THE RUNWAY CENTERLINE.

73. /USPR/ - ETS, HYDERABAD 73
FMGC PROTECTIONS
• WHEN THE AIRCRAFT REACHES 700
FEET RADIO ALTITUDE WITH APPR MODE
ARMED OR ENGAGED, THE ILS
FREQUENCY, AND COURSE ARE FROZEN
IN THE RECEIVER.
• THIS FUNCTION IS AVAILABLE (ILS TUNE
INHIBIT) WHEN AT LEAST ONE AP / FD IS
ENGAGED. ANY ATTEMPT TO CHANGE
ILS FREQUENCY OR COURSE THROUGH
MCDU OR RMP DOES NOT AFFECT THE
RECEIVER

74. /USPR/ - ETS, HYDERABAD 74
ILS APPROACH
• FOR CAT III APPROACH AUTO CALL
OUT OF RADIO ALTITUDE IS
MANDATORY AND AUTO THRUST
MUST BE IN SPEED MODE.
• CALLOUT “RETARD” COMES AT 20
FEET FOR MANUAL LANDING AND
AT 10 FEET FOR AUTOLANDING.

75. /USPR/ - ETS, HYDERABAD 75
AUTO PILOT
DISENGAGEMENT
• AUTOPILOTS ARE TO BE DISENGAGED
AT 80 FEET FOR MANUAL LANDING AND
AT THE END OF ROLL OUT FOR
AUTOLANDING.
• OTHERWISE THE AP WILL STEER THE
AIRCRAFT BACK TO THE LOCALISER
WHEN THE NOSE WHEEL STEERING IS
RELEASED.

76. /USPR/ - ETS, HYDERABAD 76
INDICATIONS OF ILS
SELECTION OF LAND MODE IS INDICATED BY
ILLUMINATION OF “APPR” PUSHBUTTON IN FCU
AND BY VARIOUS INDICATIONS ON FMA
SECTION OF PFD.
• DURING THE ARMING PHASE
CYAN “G/S” AND CYAN “LOC” CORRESPONDING
TO LONGITUDINAL AND LATERAL MODES
RESPECTIVELY. ACTIVE SUPPORT MODES ARE
SHOWN IN GREEN UNTIL LOC OR GLIDE
CAPTURE IS EFFECTIVE

77. /USPR/ - ETS, HYDERABAD 77
ILS INDICATIONS
DURING THE CAPTURE PHASE
• GREEN “LOC*” AND GREEN “GLIDE*” AND THE
CORRESPONDING SUPPORT MODES ARE DISENGAGED
AND THEIR INDICATIONS ARE CANCELLED.
DURING THE TRACK PHASE
• THE INDICATIONS ARE “LOC” AND “GLIDE” IN GREEN
COLOUR.
• BELOW 400 FEET, GREEN “LAND” INDICATION REPLACES
THESE INDICATIONS AND APPEARS ON THE LATERAL
AND LONGITUDINAL SECTIONS OF INDICATIONS.

78. /USPR/ - ETS, HYDERABAD 78
ILS INDICATIONS
DURING FLARE PHASE
• THE GREEN “LAND” INDICATION IS REPLACED BY GREEN
“FLARE” INDICATION
DURING ROLL OUT PHASE
• GREEN “ROLL OUT” INDICATION REPLACES THE
“FLARE” INDICATION.
• IN ADDITION, THE LANDING CAPABILITY IS DISPLAYED
ON THE PFD, AS SOON AS LAND MODE IS SELECTED AS “
CAT 1, CAT 2, CAT 3 SINGLE, CAT 3 DUAL”

79. /USPR/ - ETS, HYDERABAD 79

80. /USPR/ - ETS, HYDERABAD 80
LAND TEST
• THE PURPOSE OF THIS TEST, WHICH IS DONE
THROUGH MCDU, IS TO VERIFY THE
CAPABILITY OF THE INVOLVED SYSTEMS TO
PERFORM CAT III FAIL OPERATIONAL (CAT III
DUAL) AUTOMATIC LANDING.
• IT ALSO TESTS THE TAKEOVER PRIORITY
PUSHBUTTONS, THE A/THR INSTINCTIVE
DISCONNECT PUSHBUTTONS AND THE
WARNINGS ASSOCIATED TO AUTOMATIC
LANDING.
• THE LAND TEST FUNCTION IS PERFORMED IN
THE FIDS.

81. /USPR/ - ETS, HYDERABAD 81
PREREQUISITE OF LAND
TEST
• ALL THE CBS PERTAINING TO AUTO FLT AT 49 VU AND
121 VU ARE CLOSED
• AIRCRAFT ELE. POWER IS ENERGIZED (21-41-00)
• EIS START PROCEDURE IS DONE (31-60-00)
• 3 ADIRS ARE ALIGNED (34-10-00)
• AIRCRAFT HYDRAULIC SYSTEMS ARE PRESSURIZED (29-
23-00,29-10-00)
• ON 50 VU, ENGFADEC GND PWR 1&2 PUSH BUTTONS
ARE PUT TO ON
• ON 402 VU, ASKID &NW SW IS PUT TO ON
• ON MCDU SYSTEM REPORT/TEST PAGE IS BROUGHT (31-
32-00) AND
• LINE KEY ADJACENT TO AFS IS PRESSED.

82. /USPR/ - ETS, HYDERABAD 82

83. /USPR/ - ETS, HYDERABAD 83

84. /USPR/ - ETS, HYDERABAD 84
LAND TEST
• WHEN LAND TEST IS SELECTED ON THE MCDU,
FIDS CONFORMS THE GROUND CONDITION AND
SENDS SIGNALS TO THE FOUR FMGC BITES
(FG1 COM, MON, FG2 COM, MON).
• EACH BITE SENDS REQUEST SIGNAL TO THE
OPERATIONAL SOFTWARE AND THE ANSWER IS
GENERATED WHICH IS SENT BACK TO FIDS TO
AUTHORIZE THE LAND TEST INITIATION.
• IF THE FOUR ANSWERS (ACCEPTATION) ARE
NOT RECEIVED BY FIDS, THE LAND TEST
REFUSED MESSAGE IS DISPLAYED ON THE
FIRST TEST PAGE.

85. /USPR/ - ETS, HYDERABAD 85
LAND TEST
• IF THE TEST EXECUTION REQUEST IS
AUTHORIZED, THE FIDS GENERATES
DIFFERENT PAGES TO BE DISPLAYED ON THE
MCDU AND DIALOGUES WITH THE FOUR BITES
TO PERFORM THE TEST.
• THE TEST CONSISTS IN CHECKING THE
CORRECT OPERATIONS OF THE SYSTEMS
INSIDE AND OUTSIDE THE AUTO FLIGHT
SYSTEM AND INVOLVED IN CAT III AUTOMATIC
LANDING SYSTEM. (CORRECT OPERATION OF
BITES, CORRECT SYSTEM RECEPTION, SELF
TEST RESULTS AND INTERCONNECTION
VALIDITY)

86. /USPR/ - ETS, HYDERABAD 86
AFTER THE LAND TEST
• HYDRAULIC POWERS ARE DEPRESSURIZED
• THE THRUST CONTROL LEVERS ARE PUT TO IDLE STOP
POSITION
• THE ENG/FADEC GND PWR 1&2 PUSHBUTTONS ON 50 VU
ARE PRESSED.(ON LEGENDS GO OFF)
• THE RAD NAV MODE KEY IS PRESSED ON MCDU AND THE
ILS FREQUENCY AND COURSE ARE CLEARED
• IN 23VU FLT CTL PANEL FAC PUSH BUTTON IS PUSHED
(OFF LEGEND GOES OFF)
• IN 24 VU THE ELAC PUSH BUTTON IS PUSHED (OFF
LEGEND GOES OFF)
• ADIRS STOP PROCEDURES ARE DONE (34-10-00)
• EIS STOP PROCEDURES ARE DONE (31-60-00) AND
• ELECTRICAL POWER IS DEENERGISED.

87. /USPR/ - ETS, HYDERABAD 87

88. /USPR/ - ETS, HYDERABAD 88
POWER SUPPLY
• THE POWER SUPPLY REQUIRED FOR
THE ILS RECEIVER ARE SUPPLIED
FROM:
– ILS 1 401 XP AND
– ILS 2 204 XP

89. /USPR/ - ETS, HYDERABAD 89

90. /USPR/ - ETS, HYDERABAD 90
ILS 1 ILS 2
• ILS 1 IS DISPLAYED ON PFD 1
AND ND 2,
• ILS 2 IS DISPLAYED ON PFD 2
AND ND 1.

91. /USPR/ - ETS, HYDERABAD 91
THE ILS PB ON THE EFIS
CONTROL PANEL ENABLES THE
PILOTS TO SWITCH ON AN ILS
DISPLAY.. DEVIATION IS
DISPLAYED ONLY IF ILS
RECEPTION IS VALID
ILS INDICATIONS
GS LOC

92. /USPR/ - ETS, HYDERABAD 92
THE ILS DISPLAY INCLUDES
INDICATIONS FOR:
• LOCALIZER,
• FRONT COURSE,
• GLIDE SLOPE,
• INFORMATION.
ILS INDICATIONS
GS ONE SIDE ½
DEGREE (0.175
ddm)
LOC. ONE SIDE
2.5 DEGREES
(0.155 ddm)
OM MM IM

93. /USPR/ - ETS, HYDERABAD 93
ROSE MODE

94. /USPR/ - ETS, HYDERABAD 94
LOCALIZER DEVIATION
BAR
ILS COURSE POINTER
ND
ROSE ILS MODE
SELECTED ILS
INFORMATION
GLIDE DEVIAITON
LOC. DEVIATION EACH DOT 0.8 DEGREES AND GS DEVIATION
EACH DOT 0.4 DEGREES

95. /USPR/ - ETS, HYDERABAD 95
MOVES ON A SCALE
LATERALLY WITH
RESPECT TO THE
COURSE POINTER.
ND
ROSE ILS MODE
LOCALIZER DEVIATION BAR

96. /USPR/ - ETS, HYDERABAD 96
POINTS TO THE
SELECTED ILS COURSE.
ND
ROSE ILS MODE
ILS COURSE POINTER

97. /USPR/ - ETS, HYDERABAD 97
ND
ROSE ILS MODE
MOVES ON A
VERTICAL SCALE.
GLIDE DEVIAITON

98. /USPR/ - ETS, HYDERABAD 98
ND
ROSE ILS MODE
- ILS FREQUENCY
- ILS SELECTED COURSE
• ILS IDENTIFICATION
SELECTED ILS
INFORMATION

99. /USPR/ - ETS, HYDERABAD 99
SINGLE ILS RECEIVER FAILURE
• BOTH AP AND FD REMAIN ENGAGED.
• AUTOMATIC SWITCHING TAKES
PLACE TO REMAINING ILS RECEIVER
• THE LANDING CAPABILITY IS
DEGRADED TO CAT 1
• NAV ILS 1(2) FAULT DISPLAY IN THE E /
WD ASSOCIATED WITH MASTER
CAUTION AND SINGLE CHIME.

100. /USPR/ - ETS, HYDERABAD 100
DUAL ILS RECEIVER FAILURE
• AUTOMATIC GUIDANCE IS LOST
• AP DISENGAGED AND REVERSION TO
THE BASIC MODE (HDG VS OR TRK FPA)
• ONE OF THE APs CAN BE REENGAGED
IN THE BASIC MODES
• RED LOC. AND GS FLAGS ARE
DISPLAYED ON PFDs AND NDs
• AUTOLAND WARNING IS ACTIVATD
BELOW 200 FEET RA
• NO ILS AUDIO IS AVAILABLE.
• THE E / WD MESSAGE, MASTER CAUTION
AND SINGLE CHIME ARE AVAILABLE.

101. /USPR/ - ETS, HYDERABAD 101
ILS GROUND TRANSMITTER
FAILURE
• THE AUTOMATIC LANDING IS LOST.
• THE FD BARS FLASH ON PFD
• THE LOC AND GLIDES SCALES FLASH
• THE INDECES OF LOC. AND GS ARE
REMOVED FROM PFD AND ND
• NO RED LOC. OR GS WARNING FLAG
AND
• AUTOLAND WARNING BELOW 200 FEET
RA

102. /USPR/ - ETS, HYDERABAD 102

103. /USPR/ - ETS, HYDERABAD 103
TUNING THE ILS
• IN NORMAL OPERATION, FMGC TUNES THE ILS
RECEIVER AUTOMATICALLY, WITH EACH FMGC
CONTROLLING ITS OWN RECEIVERS. IF ONE FMGC
FAILS, THE EXISTING ONE CONTROLS BOTH SIDES.
• MCDU CAN BE USED TO OVERRIDE THE FMGC’S
AUTOMATIC SELECTION AND TUNING OF NAV AIDS.
• IF BOTH FMGCs FAIL, THE RMPs ( 1 OR 2)CAN BE USED
TO TUNE BOTH THE ILS.
• BELOW 700 FEET RA, ILS RECEIVES A TUNE INHIBIT
SIGNAL FROM FMGC. CHANGING THE FREQUENCY OR
COURSE IS NOT POSSIBLE.

104. /USPR/ - ETS, HYDERABAD 104

105. /USPR/ - ETS, HYDERABAD 105

106. /USPR/ - ETS, HYDERABAD 106