runway design, taxiway design

1. MODULE 6
RUNWAY ORIENTATION
⚫ Runwayare alwaysoriented in the direction of prevailing
winds.
⚫ The reason behind this is to utilize the maximum force of the
wind at the time of take-off and landing of an aircraft.
⚫ Following points need to be considered while orienting the
runways:
⚫ Avoiding delay in the landing, taxing and take-off operations.
⚫ Providing the shortest taxi distance possible from the terminal area to
the ends of runway.
⚫ Making provision for maximum taxiways so that the landing
aircraft can leave the runway as quickly as possible to the
terminal area

2. 1. Map of area and contours
2. Wind data: Tail wind, head wind & cross wind
Head wind : wind blowing from directly in front
• During Take off : provide greater lift on the wings of
the aircraft aircraft rises above the ground earlier and
in a shorter length of runway
• During landing : head wind provides the braking effect
and aircraft comes to a stop in smaller length of runway
3. Fog characteristics
Data required for runway orientation

3. 4. cross wind component
• it is not possible to get the direction of opposite wind
parallel to the center line of runway every day
• wind may blow making some angle 𝞱 with the direction of
center line of runway length
•If V is the inclined opposing wind, its component Vsin 𝞱 is
normal to the runway center line is called Cross wind
component
•If this component is in excess interrupt the safe landing &
take off operation
•It should not exceed 25 kmph

4. 5. Wind coverage:
• The % of time in a year during the crosswind component
remains within the limit of 25 kmph is called wind coverage
•The orientation of runway should be such that the minimum
wind coverage of about 95 %
cross wind component

5. 6. Wind rose :
• The average wind data of 5 to 10 years period are collected
and represented graphically in form of chart is called wind
rose
•The study of helps to determining the most suitable
orientation of Runway and also used to estimating runway
capacity
•There are two types of wind rose diagrams:
Type 1 : Showing direction and duration of wind
Type 2: Showing direction, duration and
intensity of wind

6. Type 1 Wind Rose Diagram
• In this the radial lines indicate the wind direction
and each circle represents duration of wind.
• All the plotted points are joined by straight lines.
• Best direction of runway is usually along the
direction of longest line on wind rose diagram.
• A deviation of wind direction upto ( 22.57°+
11.25 ° ) from the direction of landing and take
off is permissible

9. 10
Type 2 Wind rose diagram
• In this type each circle represents the wind intensity to
some scale. The value entered in each segment
represents the % of time in a year during which the
wind, blows from respective direction.
• The percentage of time, in a year during which runway
can be safely be used for landing and take off is
obtained by summing the percentage of time along
different directions.
Calm Period
⚫ This is the period for which the wind intensity
remains below 6.4 km/hr
= 100 – 86.5 = 13.5 %

11. Basic runway length
It is the length of the runway under the
following assumed conditions at the
airport :
1)Airport altitude is at sea level
2)Temperature at the Airport is standard
(15°C)
3)Runway is levelled in the longitudinal
direction
4)No wind is blowing on runway
5)Aircraft is loaded to its full loading
capacity

12. Performance characteristics :
✔Normal landing case
✔Normal take-off case
✔Engine failure case
• For jet engine aircrafts all 3 cases are considered
• For the piston engine aircraft only 1st
and 3rd
cases are
considered

13. 1) Normal landing case
• The landing case requires that aircraft should come to stop
within 60% of the landing distance assuming that the pilot
makes an approach at the proper speed at a height of 15 m
• The runway of full strength pavement is provided for the
entire landing distance.

14. 2) Normal take-off case
✔ The normal take-off case requires a clearway
which is an area beyond the runway and is in
alignment with the centre of runway.
✔ The width of clearway should not be less than
150 m and is also kept free from obstructions.

16. 3) Engine failure case
✔ The engine failure case may require either a clearway or a
stopway, or both.
✔ Stopway is described as an area beyond the runway and
centrally located in alignment with the centre of runway.
✔ It is used for decelerating during an aborted (terminated)
take-off.
✔ The strength of stopway pavement should be just
sufficient to carry the weight of aircraft without causing
any structural damage to the designated engine failure
speed, the pilot decelerate the aircraft and makes use of the
stopway.

18. stopway clearway

19. Correction for Elevation, Temperature & Gradient
1.Correction for elevation:-
• As elevation increases air density reduces reduces
the lift of the aircraft aircraft requires greater ground
speed to rise into air
•To achieve greater speed longer length of runway is
required.
•ICAO( International Civil Aviation Organization)
recommends that the basic runway length should be
increased at the rate of 7% per 300 m rise in elevation
above the mean sea level.

20. 2. Correction for temperature:-
• The standard temperature at the airport site can be determined by
reducing the std.mean sea level temperature of 15 ° C at the rate of
6.5 °C per 1000 m rise in elevation.
• Airport reference temperature
Ta monthly mean of average daily temperature for the hottest
month of the year
Tm monthly mean of maximum daily temperature for the same
month
• ICAO recommends rate 1% for every 1o
c rise of airport reference
temperature above the standard atmospheric temperature at the
elevation.

21. 3) Corrections for gradients:-
• As gradient become steep, more consumption of energy take
space and longer length of runway will be required to attain
desired ground speed.
• runway length after being corrected for elevation and
temperature should further being increased at the rate of 20 %
for every 1 % of effective gradient
• Effective gradient =
• ICAO further recommends that, if total corrections(elevation +
Temperature) should not be greater than 35% of the basic
runway length
Check for the total correction

22. Runway Geometric Design
ICAO gives various geometric standards for the airport design.
1)Runway length
2)Runway width
3)Width & length of safety area
4)Transverse gradients
5)Longitudinal & effective gradient
6)Sight distance

23. Runway Geometric Design
1) Runway length
The basic runway length as recommended by ICAO for different
types of airport are there. To obtain the actual length of runway,
corrections for elevation, temperature & gradient are applied to the
basic runway length.
2) Runway width
✔ ICAO recommends the pavement width varying from 45 m - 18
m for different types of aircraft.
✔ The aircraft traffic is more concentrated in the central 24m width
of the runway pavement.
✔ Minimum width of 45m should provide to protect the engine from
shoulder material

24. 3) Width & Length Of Safety Area
✔ Safety area consists of the runway, which is paved area plus the
shoulder on either side of runway plus the area is cleared, graded &
drained
✔ The shoulder are usually unpaved as they are used during emergency.
✔ ICAO recommends.
Types of
airport
Width of safety
area
Non-instrumental
runway
A,B&C
D&E
150 m
78 m
Instrumental runway A,B,C,D&E Mini. 300 m

26. Typical C/S of runway for ILS approach is shown
below
(Instrumental Landing Systems)

27. (Instrumental Landing Systems)

28. 4) Transverse gradient
✔ Transverse gradient is essential for quick drainage of
surface water. If surface water is allowed to pond on the
runway, the aircraft can meet severe hazards.
✔ ICAO recommends that the transverse gradient of runway
pavement should not exceed 1.5% for A,B, C & D 2 % for
D & E types.
✔ ICAO does not recommends that the minimum
transverse gradient of runway pavement but it should not
greater than 0.5 %.

29. 5) Longitudinal & Effective Gradients.
✔ The longitudinal gradient of runway increases the required
runway length.
✔ ICAO recommendation as follows
Types of
airport
Longitudinal
gradient
Effective
gradient
A,B & C 1.5 % 1 %
D & E 2 % 2 %

30. 6) Sight distance (is the length of roadway visible to a driver)
✔ Two runways or a runway & taxiway intersect each other, there are chances
of collision of aircraft, if sufficient sight distance are not available.
✔ ICAO recommends that for A,B & C types of airports, any two points 3 m above the
surface of runway should be mutually visible from a distance equal to ½ the runway
length.
✔ For D & E types of runway there should be unobstructed line of sight from any point
3 m above runway and to all other point 2.1 m above runway within a distance of at
least ½ the length of runway.

31. TAXIWA
Y

32. Taxiway Geometric Design
ICAO gives various geometric standards for the airport design.
1)Taxiway length
2)Taxiway width
3)Width & length of safety area
4)Transverse gradients
5)Longitudinal & effective gradient
6)Sight distance
7)Turning radius

33. ✈ Length of taxiway:
✈ As short as possible.
✈Increased number of taxiways have to be provided along the
runway.
✈Width of taxiway:
✈ It is observed that the width of a taxiway is much lower than
the runway width, as aircraft is not airborne and speeds
are small.
✈Varies between 22.5 m & 7.5 m

34. ✈Width of taxiway:
✈ Width of taxiway (ICAO)
✈Longitudinal gradient:
✈ Level taxiway are operationally more desirable.
✈If gradient is steep, it affects fuel consumption.
✈ As perICAO,maximum longitudinal gradient is 1.5%
for
Airport Code Taxiway width
A 22.5 m
B 22.5 m
C 15.0 m
D 9.9 m
E 7.5m

35. ✈ Rate of change of longitudinal gradient:
✈ Available sight distance on the pavements is affected by the
rate of change of longitudinal gradient.
✈As per ICAO, the maximum change in pavement longitudinal
gradient is 4% for A&B category of airport & 3.33% for C,D&E
category of airports.
✈ Sight distance:
✈ As speed of aircraft on taxiway is lower than the speed
on
runway, the smaller value of sight distance will be sufficient on
the taxiway.

36. ✈Sight distance:
✈ICAO recommended that the surface of taxiway mustbe
visible at least up to a distance of X- from any point at a height
of Y above the taxiway surface
.
✈ Transverse gradient:
✈ Adopted same as recommended for runway.
✈Transverse gradient is essential for quick drainage of surface
water.
Airport Code Y X
A 1.5 m 150 m
B 2.0 m 200 m
C,D&E 3.0 m 300 m

37. ✈ ICAO recommended that the transverse gradient of runway
pavement should not exceed 1.5% for A,B&C & 2% for
D&E types. Shoulder are usually provided with steeper
gradients.
✈Width of safety area:
✈ Safety area is made up to partially paved shoulders on either
side plus the area which is graded & drained.

38. ✈ Turning radius:
✈ Change in aircraft path is doneby providing a horizontal
curve.
The design should be such that the aircraft can negotiate the
curve without significantly reducing the speed.
Circular curve of large radius is provided.
Radius can be obtained from :
1. R = V2
/125f
Where, R=radius in meter, V=speed in Kmph, F=Friction btw tire
and pavement = 0.13

39. 2. Horenjeff equation :
R =
W Wheel base of aircraft (m)
T Width of taxiway pavement (m)
S Distance between midway of main gear and the edge of
pavement (m)
Minimum distance of 6m is maintained between the nearby main gear
and edge of pavement
3. Minimum value of radius
i) For sub sonic jet= 120 m
ii) For super sonic jet = 180 m

41. DESIGN OF EXIT TAXIWAY
1) The most significant factor is the exit speed of aircraft.
2) Slightly widened entrance of 30 m will be provide.
3) Total angle of turn is 30
° - 45° can be negotiated in a satisfactory
manner.
4) The turning radius should be calculated by the following formula
5) A high turn-off speeds of 65-95 kmph a compound curve is necessary
to minimize the tire wear on the nose gear.
6) The length of longer radius curve can be roughly obtained by
(value of C=0.39 )
Length of central curve ,
R=

42. 7) Deflection angle of entrance curve
Deflection angle of central curve , 𝞓₂ = Total angle - 𝞓₁
8) Stopping distance (SD)
Where d deceleration rate ;assume d= 1 m/s²

44. TERMINAL AREA PLANNING (Airtport planning &
design,pg no.374)
• The transition of passengers from ground to air occurs in the terminal
area
• The degree of development in the terminal area will vary the volume
of airport operations , volume of air traffic , the number of
passengers and airport employees etc
• The various facilities provided in the airport building are:
Passengers and baggage handling counter
Baggage claim section
Enquiry counter
Public telephone booth
Waiting hall for passenger and visitors
Toilet facilities
Fist aid room
Banking facilities
General store
Weather bureau
Custom control
Passport and health
control
Control tower etc

45. Planning consideration
3 concepts are there for planning of the terminal building:
1. Centralization system
2. Decentralization system
3. Decentralized- centralized system
1. Centralization system
• All passengers, baggage's and cargo are routed through a central
location and then passed on to the respective aircraft positions
• This system is convenient when the aircraft parking area is within
walking distance of 180 m
• It is economical due to the fact that many of the common facilities
may be used to serve a large number of aircraft gate positions

46. 2. Decentralization
• The passenger facilities are arranged in smaller units and repeat
in one or more buildings
• Each unit is arranged in smaller units around one or more aircraft
gate positions and it serve the passengers using those gate
positions
• Passenger and baggage arrive at point near the departing plane
and all the airline functions are carried out adjacent to departing
plane
• This system proves to be uneconomical when the number of
gates required exceeds 6
3. Decentralized- centralized system
• More popular in the design of air terminals throughout the world
• Due to considerable increase in the volume of air traffic, and the
concept of the combination of above 2 systems is becoming
more acceptable for design of a modern terminal building
• In this system each individual airline operation is centralized

47. • Facilities are provided in units of manageable size providing
minimum walking distance from kerbside to gate positions
• As traffic grows and 1 unit become saturated ,further units are
added as required, without disturbing the use of existing ones.

48. SITE LOCATION
• With respect to the overall layout of an airport, the terminal
building should be well placed to carryout its functions in the best
possible manner.
• Some of the basic requirements while deciding site for terminal
building:
It should be centrally located with respect to the runway
It should have convenient and easy asses to the highway
It should have enough provision for future expansion
It should have favorable orientation with respect to wind
,topographical features of the area etc
It should be adequate space available for parking of vehicles
Utilities like water, sewage and telephone should be easily
available

49. NOISE CONTROL
• There will be considerable noise inside the terminal building due to the
presence of passengers
• Some of the portion like room of control tower from where information
is to be sent out, is to constructed of noise proof material
• The designer of terminal building should study the problem of noise
control and make suitable provision for control of noise
SPACE REQUIREMENT
• The determination of space requirements at the terminal building is
strongly influenced by level of service desired
• The approximate % of space among the various purposes in a terminal
building as:
i. Airport operation – 38 %
ii. Airport administration- 17 %
ii. Public space – 30 %
v. Utilities, shops etc – 15 %

50. AIR TRAFFIC CONTROL (Page no.424))
• Air traffic control is necessary because of safe guard to
life and property and for stimulate the traffic movements
• 2 basic characteristics of aircraft make the air traffic
control a complex problem
1. Aircraft must continue flight and cannot afford to stop in
the air space
2. Aircraft land with gliding slope detected by latitude at
which trouble occurs. During bad weather , when poor
visibility, certain information regarding alignment height
and distance from the runway to be provided to the pilot
through some instruments

51. IMPORTANCE OF AIR TRAFFIC
CONTROL
• It avoids the possibility of occurrence of accidents in the
air
• It grants the economic and efficient utilization of the
aircraft and the airport
• It guides the aircraft to their destinations safely and
speedily
• It increase the confidence of passengers using the
facilities of air travel
• It separates the aircraft to a safe distance during their
flight both vertically as well as horizontally

52. Need of Air traffic control
1. Airport traffic control:
• To guide the aircraft , desiring to land or take off
• To control the taxing of arriving and departing aircraft
on the airfield between the apron and the runway
2. Airway traffic control:
• This regulates the movements of aircraft along the air
routes with adequate lateral and vertical separation to
avoid collision
3. Airway communication:
• This deals with conveying of airway and weather
information to the during the flight

53. AIR TRAFFIC CONTROL NETWORK
1. Control within terminal area
2. Control over airways
3. Airway communication
1. Control within terminal area
• Done from airport control tower, which is located in the terminal
area and act as nerve center of an airport
• Safety of aircraft operation and effective capacity of an aircraft
depend upon the skill of controller, operating the system
• Informations are issued to the pilot regarding airport conditions,
airway traffic, visibility, speed and direction of ground wind ,
pressure and other information for the safe operation

54. 2. Control over airways
• The control is provided by number of Air route traffic control
center (ARTC)
• These centers are usually located at major airports such as,
Bombay, Madras, Calcutta etc
• Each center controls a certain definite geographical area thus
covering the entire area of the country
• As aircraft crosses over the boundary of one of the control area, it
is taken over by the ARTC of another area
3. Air communication
• The main function is to give certain information to the pilot,
before and during the flight, regarding weather change
• This is usually done through flight service stations , these
stations are located at the airports and also along the airways

55. AIR TRAFFIC CONTRO AIDS
During all weather conditions, the following air traffic control
aids are always available to the pilot during the flight
1. Enroute Aids or Airway aid
2. Landing Aids
Enroute Aids
1. Airway beacon:
• Used only for air navigation
• They were spaced about 40 km apart along the air
routes to guide the pilot from one airport to another
• These are now replaced with more effective controls

56. 2. Low/Medium frequency radio range:
• The 4 way LF/MF radio range emits radio along 4 direction, each
beam is directed towards an airway
• The pilot flying on an airway, along which a radio beam has been
directed ,tunes of the frequency of the radio beam
• If the pilot hears a steady tone, it indicates that he is on right course
3. Very high frequency omni directed range (VOR)
• Whereas LF/MF radio range emits
signals only in 4 directions , VOR does it
along an indefinite number of courses on
which pilot can fly
• Main advantage is that it is susceptible
to static interference and remains
effective even during thunderstorm

57. 4.Air ground communication
• It is necessary to provide the pilot weather information
and other flight instructions as he progresses along an
airway
• Sometimes pilot may required to change his route,
while in air in order to bypass certain area due to
adverse weather conditions ahead
5. Tactical air navigation
• Best suits for tactical needs of military
6. Distance measuring equipment
• It indicates to the pilot the distance to or from point,
and pilot get idea of his position with respect to the
airway

58. Landing Aids:
1. Instrumental landing system
• Most widely used system of landing
• It consists of telecommunication aids to the pilot to enable
him to approach the runway and make successful landing
under condition of poor visibility
• ILS system provide facilities for landing even when visibility
is poor
• ILS consists of following 3 components:
Outer and middle marker :
✔ These are small radio transmitters which serve as position
reporting points
✔ As the pilot passes over the marker, he find a visual
indication in the cockpit and receive high pitched steady
tone through the earphone

59. Glide slope antenna :
✔ It transmit radio beam signal (very high frequency
omni directional range) in a horizontal plane, and
indicate to pilot , the correct angle of descent to the
runway
Localizer antenna:
✔ It emits radio beam signal (very high frequency omni
directional range) in a vertical plane and indicate pilot
whether he is left or right of the correct alignment for
approach to the runway
✔ It is located along the extended center line of runway

61. 2. Precision approach Radar (PAR) :
• It serve the same purpose as an ILS except that the guidance
information reaches the pilot through his hearing aid
• PAR gives to the controller the picture of descending aircraft both
in plan and in elevation
3. Airport surveillance radar :
• It is an instrument which provide to the controller at the tower an
over all picture of all the aircraft within the air space surrounding
the terminal
• It is effective up to a distance of 50 km to 100 km
4. Approach lights:
• Near the runway , the pilot changes over from instrumental to
visual landing
• Only few seconds are available to the pilot during which he has to
complete the landing operation.
• To complete the landing operation successfully, the approaches
and runways are adequately should lighted properly.