1. Unit-5-ATC & Aerodrome Design 1401
VISUAL AIDS FOR NAVIGATION, VISUAL AIDS FOR DENOTING OBSTACLES EMERGENCY AND OTHER SERVICES

2. Syllabus
Visual aids for navigation Wind direction indicator – Landing direction indicator – Location and characteristics of signal area – Markings, general requirements – Various markings – Lights, general requirements – Aerodrome beacon, identification beacon – Simple approach lighting system and various lighting systems – VASI & PAPI - Visual aids for denoting obstacles; object to be marked and lighter – Emergency and other services.

3. Visual and Nav Aids
Visual aids for navigation Wind direction indicator – Landing direction indicator – Location and characteristics of signal area

4. Runway of Chennai Airport

5. Chennai Terminal

6. Chennai Airport Specification
Location Trisoolam;MSL=16m
Bearing=12*59’N 80*E
Runway 1. 07/25; 3.658m Asphalt
Runway 2.12/30; 2.05m Asphalt/Concrete

7. Visual Aids for Navigation
Stop Bars on Domestic and International runways
Parking stand with center line lighting system
Instrument Landing system (ILS)
During Day time:
Windsocks, Windpipe,
During Night Time:
Beacon lights

8. Wind direction Indicator-Windsock/Wind cone

9. Wind direction indicator-Windsock
Pilot check windsock or Wind Tee or Tetrahedron
Wind direction indicators include a wind sock, wind tee, or tetrahedron.
Located in a central location near the runway and may be placed in the center of a segmented circle identifying the traffic pattern direction, left-hand pattern.
The windsock a good source of information since it not only indicates wind direction, but also allows the pilot to estimate the wind velocity and gusts or factor.
Windsock extends out straighter in strong winds and will tend to move back and forth when the wind is gusty.
also look at the windsock, if available

10. Visual Aids for Navigation

11. Wind cone or Windsock
Weather resistant man-made fiber, impregnated fluorescent orange,
mounted on a ring, attached to a bearing mounted, free rotating
counter balanced assembly on a steel tubular column.
Column: galvanized column raised or lowered by means of a lifting lever associated with a spring counter balance unit.
Floodlights4 x 80W sealed beam floodlights.
Obstruction Lights One ZA753/6 double obstruction light c/w automatic lamp with changeover relay.
GlasswareTwo red glass domes for ZA753/6.Made of Handmade Fiber

12. Wind cone Construction

13. Wind Tee & Tetrahedron and
Wind tees and tetrahedrons can swing freely, and will align themselves with the wind direction.
TETRAHEDRON- A device normally located on uncontrolled airports and used as a landing direction indicator. The small end of a tetrahedron points in the direction of landing.
The tetrahedron indicating wind direction by pointing into the wind
The wind tee and tetrahedron be manually set to align with the runway in use;

14. Tetrahedron for Wind Direction

15. Tetrahedron

16. Wind direction Indicator

17. Wind Direction Indicator

18. Aerodrome beacon, identification beacon
Nav Aids and Beacons
Aerodrome beacon, identification beacon

19. Landing Direction Indicator
A device to pilots indicating visually aircraft direction designated for landing or takeoff.

20. Landing Direction Indicator

21. Types of Landing based on Visibility
Cat I landing: < 800 m Visibility on precision approach
Cat II Landing: = 350 m visibility Precision instrument approach
Cat III Landing: = 200 m visibility divided into Cat III A(100m), Cat III B (50m) and CAT III C( 0m)

22. 5 Phases of Approach on ILS
Arrival
Initial Approach of flight for aligning the aircraft for FAF-Final Approach Fix to the Runway
Intermediate approach for complex approach
Final Approach-4 to 12 to 6*
Missed approach- an optional case in case of VFR not obtained

23. Five Phases of Flight for ILS
Arrival: Pilot navigates to the Initial Approach Fix .
Initial Approach:Pilot commences the navigation of the aircraft to the Final Approach Fix (FAF), a position aligned with the runway,
Intermediate Approach: an additional phase in more complex approaches that may be required to navigate to the FAF.
Final approach: between 4 and 12 nms of straight flight descending at a set rate (usually an angle of between 2.5 and 6 degrees).
Missed Approach: an optional phase; VFR not have been obtained at the end of the final approach, this allows the pilot to climb the aircraft to a safe altitude and navigate to a position to hold for weather improvement or from where another approach can be commenced

24. Decision Height
A decision height (DH) - the safe height to the Pilot for Climb in the precision approach when required VFR reference to continue the climb has not been acquired.
A specified height above the ground in an instrument approach procedure & expressed in feet above ground level.

25. Descent Altitude

26. Decision Height

28. Airport Characteristics

29. Instrument Landing System

30. Instrument Landing System
A precision approach guidance system providing precision guidance to aircrafts approaching and landing on a runway
Consist of Localizer, Marker Beacons and DME
Using combination of radio signals and high-intensity lighting arrays for a safe landing during low ceilings or reduced visibility due to fog, rain, or blowing snow
Aircraft guidance provided by the ILS receivers fitted in the aircraft

31. Localizer Array

32. Localizer
An Array of directional antennas fitted at the end of the runway
Two signals transmitted on carrier frequency range  MHz and  MHz & modulated at 90 Hz & at 150 Hz and transmitted from separate antennas.
Each antenna transmitting a narrow beam, one s to the left of the runway centerline & the other to the right
Depth of modulation at the Loc RX indicate the aircrafts position ( m=0, aircraft at the centerline)

33. ILS — Localizer

34. Localizer Antenna Path

35. ILS — Glideslope

36. ILS Localizer beam width = 3 to 6*
ILS use a second beam a "glide slope" beam giving vertical information to the pilot. -glide slope usually 3° wide with a height of 1.4° .
A horizontal needle on the VOR/ILS head indicates the aircraft's vertical position

37. Glidepath

38. Glidepath

39. Airport Beacon
A device located at the airport to attract attention; mounted on the top of control tower, above other buildings of the airport. Producing flashes.
most effective from one to ten degrees above the horizon
Flashing Xenon Rate-24 to 30 per minute with lighted green and white color

40. a. Airport Beacon

41. b. Rotating beacon

42. Marker Beacons
A particular type of VHF radio beacon used in aviation in conjunction with an instrument landing system (ILS), to give pilots a means to determine position along an established route to a destination such as a runway.
they have become increasingly limited to ILS approach installations

43. Marker Beacons at the Runway
3 marker beacons (outer, middle and inner) located in front of the landing runway and indicate their distances from the runway threshold.
Outer Marker (OM) = 4 to 7 miles from the runway.
Middle Marker (MM) = about 3,000 feet from the landing threshold, and
Inner Marker (IM) = between the middle marker and Runway threshold

44. Markers

45. Markers WHITE Low Visibility AMBER Low Visibility With Missed Approach
BLUE
Before
A Final
Approach

46. Marker Beacons OM-Blue-400 Hz-
MN-Amber-1300 Hz- for low visibility with missed approach
IM-White-3000 Hz-low visibility condition

47. Aerodrome Locations

48. Aerodrome Locations Runway –Main and Secondary Terminal Building
Control Tower
Taxiway
Holding Points
Serving Area
Sterile Area
Barrier

49. Various Aerodrome Locations
Main Runway( most frequently used depending on Wind direction) & Secondary Runway (when wind changes the direction)
Terminal Building ( for holding passengers and for immigration and customs) &
Control Tower ( a building with good visibility for aircraft maneuverability)
TaxiwayLights- a link between Runway and diff parts of airport(terminal and hangars), marked by yellow lines
Holding Points ( a place where aircrafts stopped on the taxiway for permission from Control tower to proceed to the runway). and Servicing Platform
Servicing Area: Aircraft Servicing Area-An area reserved for pre and post flight operations between two flights.

50. Runway Markings
Threshold: marked by a line of green lights-Four stripes on either side of the centerline at the end of the runway
Magnetic Runway Heading-29- number, to the nearest one-tenth of Magnetic North
Landing aiming point a visual cue, it is generally 1,000 feet from the threshold
Touch Down Zone Markers:Meant to help define the touchdown zone, they show distance information in 500 foot increments
Distance to go Markers:number denotes the distance remaining, in thousands of feet.
Runway Designator Sign:the departure end of runway 9 is to your left and the departure end of runway 27 is to your right.

52. Define: Runway Number
Whole number nearest one-tenth (degrees divided by 10 rounded) of the magnetic azimuth of the runway centerline, measured clockwise from the magnetic declination
Runway 36 would be aligned in roughly a 360 degrees direction (magnetic north), Runway 9 would be used for a runway with a 90-degree alignment .

53. Runway Number

54. Runway Number
Runway number is one tenth of the runway centerline's magnetic azimuth, measured clockwise from the magnetic declination
Runway number between 01 and 36
Runway Number indicate runway's heading
A runway - 36 –Pointing 360* north
Runway 09 points East = (90°),
Runway 18 south (180°), and
Runway 27 points west (270°).

55. Holding Point

56. Various Aerodrome Locations
Sterile Area-Beginning of the Runway where no aircraft can be parked
Barrier- A safety net to the stop the aircraft during emergency
Windsock (Bright Orange Tubes to indicate Wind Direction) and Arrestor Gear( a cable stretched across the runway for emergency)
Airfield Identification- A Square Signal that can be seen from the air.

57. Taxiway Lights

58. Designation on the Taxiway
designation of the taxiway on which the aircraft is located. These signs are installed along taxiways either by themselves or in conjunction with direction signs or runway holding position signs.

59. Chennai Airport

60. Airport Lighting & Aids
Lights, general requirements –– Simple approach lighting system and various lighting systems – VASI & PAPI - Visual aids for denoting obstacles; object to be marked and lighter – Emergency and other services

61. Runway Lighting

62. Airport Lights
Ground lights for precision approach -6 direction and 24 direction;Runway lighting-touch down, centre line, end lights-VASI & PAPI ( Visual approach and precision approach)
Taxiway lights
Beacon lights for Airport Identification= Signaling lighting at Control Tower

63. Airport Lights

64. Runway Lights
Listing, Color,

65. Listing Approach Lights-6 direction and 24 direction
Threshold Lights-green lights extending to runway edge.
Touch down Zone Lights-High intensity lights extending to 600 m of Threshold
Centerline lights-embedded 15m interval white lights
Edge Lights-White color lights
Runway End Lights-4 Uni-directional Red color lights
Taxiway centerline Lights

66. Airport Lighting

67. Color
Strobing White-Omnidirectional Approach Lights- strobing towards the threshold
Threshold lights- unidirectional green extending to Runway Edge
Centerline-White color light;
Touch Down Lights-
Edge-White color lights;
Runway Threshold-Green Red or Red-Red ;
Taxiway Centerline-Green –Green

68. APPROACH LIGHTs

69. Runway Lights from Approach to

70. 1.Various Lights at Runway
Edge Lights
Threshold Lights
Center line Lights
End Lights
Touch Down Zone Lights
Runway Guard Lights

71. Threshold and Touch down Lights

72. 4. Touchdown Zone Lights

73. Touchdown Zone Lights

74. Runway edge lights

75. 3. Runway Centerline Lights

76. Simple Runway Approach lighting
Omni-Directional Approach Lights used to identify the approach end and centerline of the runway
Horizontal Bright beam pattern flash sequentially strobing rolls toward the runway threshold
Strobing flash helps the pilot to identify the runway in use
Strobing 60 Flash/Minute,360* Hori and 8* Vertical Beam

77. Runway Centerline Light
Strobing Runway light towards
Threshold-White White
60 Flash/Minute

78. Simple Approach Runway lighting system
Centerline Lights:Row of lights on the centre line of runway and displaced 900 m from runway threshold.
Approach lights placed at 30 m from the threshold & has two crossbar lights.First crossbar light been placed 150 m away from the threshold. Second crossbar been placed 300 m away from the threshold
Threshold Lights are Green Ground Lights
Edge lights distributed symmetrically on both sides of the runway at 60m intervals
End of Runway Lights-Red
Taxiway Lights-Blue Lights

79. Operation of Approach Lights
Operational from sunset to sunrise
Operational from Sunrise to sunset on visibility <3000 m
Operational when requested by pilot
Operational at any other time based on weather conditions, & when desirable for the safety of air traffic
Operational when the associated runway lighting is operated.

80. Runway edge lights
Operational on the edges of runways during darkness and at poor 60 m intervals
3 Types of Edge lights :1. High Intensity Runway Lights (HIRL)2.Medium Intensity Runway Lights (MIRL) & 3.Low Intensity Runway Lights (LIRL)
Edge Lights are white in colour

81. Centerline Lighting Used for Steering the Aircraft to the centerline
High Power LED, can withstand high windspeed of 160 mph
White for the First path of the Runway, Alternate White and Red Light embedded on the runway for 600m and Red for the last 300m @ 15 m intervals

82. Centerline lights (first R & W and last R) @ 15m

83. 3. Runway Centerline Lights

84. Touch Down Zone Lights
White Lights Bars on either side of the Centerline
3 White Lights in Each Row upto 900m or the midpoint whichever is less on either side of the centerline lights

85. Threshold Lights Red & Green lights located at the end of the Runway
Red for Departure to Pilot and Green for Landing to Pilots

86. Taxiway Lighting For Pilots to get off the runway as fast as possible
Green color(centre line) lights at 15m intervals
Consisting of Edge Lighting(Blue), Centerline Lighting (green),

87. 2.Taxiway lighting

88. Runway Guard Light

89. Runway Guard Lighting

90. Approach Lighting System
VASI & PAPI

91. Approach Lighting System

92. Approach Lighting System
Visual Approach Slope Indicator-VASI
Precision Approach Slope Indicator-PAPI

93. VASI Visual Approach Slope Indicator
A system of Lights ( White and Red) arranged for descent guidance information
Visible at 5-8 KM at day and 25 KM at night, providing safe obstruction clearing within +/-10* of the centerline of the extended runway
VASI initiated only when theAircraft visually aligned with the Runway
VASI arranged in BARS as Rear, Middle and Far
Grouped as 2 Bar( near and far) & 3 Bar ( near, middle and far) VASI
minimizes the possibility of undershooting or overshooting the designated touchdown area.

94. Principle Color differentiation between Red and White on Glide path
3 situations 1.above the glide path, 2.on Glide path and 3. below glide path
All White when Glide path slope High
Red & White bar on Approach Slope
All Red when Slope is low

95. Schematic

97. 2 Bar VASI Far Bar Far Bar Near Bar Near Bar Above glide path
Below Glide path
On Glide path
Red Illumination
White Illumination

98. VASI

99. Tutorial
Draw the schematic of 3 Bar Vasi showing the illumination of lamps

100. Precision Approach Path Indicator-PAPI
Principle, Schematic

101. PAPI A Safe, accurate Glide Approach system for the Pilot
Located on the left or right side of the runway at 90˚ to the runway centre line spaced at 9 meters apart in Boxes, 300m away from the Landing Threshold
PAPI indicates the aircraft position wrf to glidepath; too high or too low wrt white color light or red color light to the Pilot
VISIBLE up to 8 KM during the day and 25 KM at night using a 2 Lamp Papi.
Lamps are adjusted to the correct glide slope angle (± 3' of arc)
Made of LEDs with lifetime operation of 50,000 hours

102. Alsthoms PAPI-4 Box light system

103. View of PAPI

104. PAPI (Precision Approach Path Indicator)

105. PAPI-Precision Approach Path Indicator
Precision Approach Path Indicator (PAPI) -a light system positioned beside the runway consisting of two, three, or four boxes of lights giving visual indication of an aircraft's position on the glide path for the associated runway.
An instrument helping to carry out a correct approach (in the vertical plane) on an aerodrome
Located 300 meters beyond the landing threshold of the runway.
PAPI seen to the right of the runway.
More number of red lights visible means the aircraft is below the glideslope.

106. 4 Bar Papi

107. PAPI

108. PAPI

109. PAPI seen to the right of the runway with number of red lights visible means that the aircraft is below the glide slope.

110. PAPI-4 BOX LIGHT SYSTEM
Precision Approach Path Indicator (PAPI) a system of ei four or two identical lights
Light box assembly consist of a stable optical platform supporting the lamp, reflector, lenses, color filter, and tilt switch.
Light from the lamp collected and focused to a convex lens set producing the field of illumination into the approach area.
Units placed on the left of the runway aimed outward into the approach zone on a line parallel to the runway.
Front face of each unit is perpendicular to the runway centerline.

111. Advantages Outstanding photometric performance.
Four-leg design makes each light housing assembly very stable reducing maintenance and increasing airfield utilization
Quartz halogen lamps with rated life of 1200 hours.
A wireless remote control system obviates the need for long runs of control wire to distant PAPIs

112. Obstructions at Airport

113. Use of obstacle lights
High-intensity obstacle lights are intended for day use as well as night use.
Low-intensity obstacle lights, Type A or B, shall be used where the object is a less extensive one and its height above the surrounding ground is less than 45 m.
Low-intensity obstacle lights, Type C, shall be displayed on vehicles and other mobile objects excluding aircraft.
Medium-intensity obstacle lights, Type A, B or C, shall be used where the object is an extensive one or its height above the level of the surrounding ground is greater than 45 m.

114. Obstruction Lights
Terminal Building
Hangers

115. Effects of Obstacles near the Aerodrome
Limiting the distance available distance for take-off and landing
Poor visibility and temperature affecting the operations of flight into or out of an aerodrome.
Tall Structures near the Airport affect a fully loaded aircraft with slow climbing rate
Signals received by aircraft from Tall installations and Structures located close to aeronautical installations distort the signal,
Heights of structures must therefore be controlled in order not to penetrate these areas of the airspace

116. Obstruction Lights
Airport beacon-airport beacon normally located within 5,000 feet of the airfield
Identification or code beacon- identifying airfield where the airport beacon is more than 5,000 feet away from the airfield
Obstruction beacon-indicating the visual identification of natural obstacles or structures 45 meters above airfield elevation for hazards like towers, buildings, tall bridges, communication towers etc .

117. b. Identification Beacon

118. b. Identification Beacon
Flashing
Night Visibility 15 Miles
120V, 250 W
Metal Halide Bulbs used ( 3-5 Years of life)

119. c. Obstruction Lamp

120. c.Obstruction lights Working voltage from C85V to 260V
Anti-bounce, corrosion proof, anti-lightening strike ,easy to install. with four synchronous flash control methods to select
rated power waste 　110W
light color options 　 red, green and white
level of protection 　IP65

121. Obstacle lights when heights less than 45’