Lecture notes in Airport Engineering

Tribhuvan University Institute of Engineering

Pulchowk Campus Department of Civil Engineering

Introduction to Airport Engineering

(M. Sc Transportation Engineering)

Prepared by:

Dr. Padma Bahadur Shahi March, 2011

Airport Engineering/Dr. Padma Shahi 2

Contents

1. Airport Engineering ............................................................................................................................................ 3

2. Role of Air transportation: ................................................................................................................................... 3

3. Air Transport in Nepal ......................................................................................................................................... 3

3.1. Aviation Chronicles..................................................................................................................................... 3

4. Some organizations related to the civil aviation: .................................................................................................. 11

5. Classification of Airports:................................................................................................................................... 12

5.1. Based on take-off and landing ................................................................................................................... 12

5.2. Based on the Geometric design (ICAO) ...................................................................................................... 12

5.3. Based on function: ................................................................................................................................... 13

5.4. Military aviation airports ............................................................................................................................ 13

6. Airlines frequency at different airports of Nepal: .................................................................................................. 14

7. Aircraft Component parts .................................................................................................................................. 14

8.1 Engine .................................................................................................................................................... 21

8.2 Fuselage: ................................................................................................................................................ 22

8.3 Wings: .................................................................................................................................................... 22

8.4 Three controls: ......................................................................................................................................... 22

8.5 Tricycle under-carriage: ............................................................................................................................ 23

9. Aircraft Characteristics: ..................................................................................................................................... 24

9.1 Size: ....................................................................................................................................................... 24

9.2 Make a figure of Minimum turning radius: ................................................................................................... 27

9.3 Minimum Circling Radius in Space: ............................................................................................................ 27

9.4 Capacity of aircraft: .................................................................................................................................. 27

9.5 Takeoff and landing distance: .................................................................................................................... 27

9.6 Speed of aircraft: ...................................................................................................................................... 28

9.7 Weight of air craft and wheel configuration:................................................................................................. 28

9.8 Jet Blast: ................................................................................................................................................. 28

9.9 Fuel Spillage ............................................................................................................................................ 28

9.10 Noise: ..................................................................................................................................................... 28

10. Aviation System Planning ................................................................................................................................. 28

10.1 Data base for airport system Planning: ....................................................................................................... 29

10.2 Comprehensive Airport system analysis ..................................................................................................... 31

10.3 Airport Master Plan................................................................................................................................... 32

10.4 Elements of Master Plan: .......................................................................................................................... 32

10.5 Steps of Master Plan ICAO: ...................................................................................................................... 33

11. Airport Site Selection ........................................................................................................................................ 33

12. Predicting air travel demand .............................................................................................................................. 33

12.1 Conventional methods of forecasting ......................................................................................................... 35

12.2 Analytical methods of air travel demand forecasting .................................................................................... 37

12.3 Air trip generation models ......................................................................................................................... 39

12.4 Air trip distribution models ......................................................................................................................... 39

12.5 Modal choice models ................................................................................................................................ 42

13. Airport Capacity ............................................................................................................................................... 43

13.1 Capacity, Demand and Delay ................................................................................................................ 43

13.2 Runway capacity ................................................................................................................................... 44


13.3 Determination of runway capacities and delay .................................................................................... 45

1. Airport Engineering

Airport engineers design and construct airports. Airport engineers must account for the impacts and demands of aircraft in

their design of airport facilities. These engineers must use the analysis of predominant wind direction to determine runway

orientation, determine the size of runway border and safety areas, different wing tip to wing tip clearances for all gates and

must designate the clear zones in the entire port.

Aviation is the design, development, production, operation, and use of aircraft.

2. Role of Air transportation:

Improves accessibility to otherwise inaccessible areas

Provides continuous connectivity over land and water (no change of equipment)

Saves productive time, spent on journey

Increase the demand of specialized technical skill workforce

Adds to the foreign reserve through tourism

Speed: Modern jet can travel at 1000 km/h

Promotion of trade and commerce

Military use

Relief and rescue operations

Aerial photography

Agricultural spraying

Safety: safe mode of transport. Disadvantages of air transport 1. Heavy funds are required, not only initially but also during operation 2. Operations are highly dependent up on weather conditions. 3. It needs highly sophisticated machinery: 4. Adds to the outward flow of foreign reserve 5. Noise pollution 6. Safety provisions are not adequate 7. Specific demarcation of flight paths and territories is essential. 8. High energy consumption

3. Air Transport in Nepal

3.1. Aviation Chronicles

1949: The date heralded the formal beginning of aviation in Nepal with the landing of a 4 seater lone powered vintage Beach-craft Bonanza aircraft of Indian Ambassador Mr. Sarjit Singh Mahathia at Gauchar.

1950: The first charter flight By Himalayan Aviation Dakota from Gauchar to Kolkata.

1955: King Mahendra inaugurated Gauchar Airport and renamed it as Tribhuvan Airport.

1957: Grassy runway transformed into a concrete one.

1957: Department of Civil Aviation founded.

1958: Royal Nepal Airlines started scheduled services domestically and externally.

1959: RNAC fully owned by HMG/N as a public undertaking.


1959: Civil Aviation Act 2015 BS. promulgated.

1960: Nepal attained ICAO membership.

1964: Tribhuvan Airport renamed as Tribhuvan International Airport.

1967: The 3750 feet long runway extended to 6600 feet.

1967: Landing of a German Airlines Lufthansa Boeing 707.

1968: Thai International starts its scheduled jet air services.

1972: Nepalese jet aircraft Boeing 727/100 makes a debut landing at TIA. ATC services taken over by Nepalese personnel from Indian technicians.

1975: TIA runway extended to 10000 feet from the previous 6600 feet.

1976: FIC (Flight Information Center) established.

1977: Nepal imprinted in the World Aeronautical Chart.

1989: Completion of International Terminal Building and first landing of Concorde.

1990: New International Terminal Building of TIA inaugurated by King Birendra.

1992: Adoption of Liberal Aviation Policy and emergence of private sector in domestic air transport.

1993: National Civil Aviation Policy promulgated.

1995: Domestic Terminal Building at TIA and Apron Expanded.

1998: CAAN established as an autonomous Authority.

2002: Expansion of the International Terminal Building at TIA and the construction of a new air cargo complex.

2003: Rara airport (Mugu), Kangeldanda airport (Solukhumbu) and Thamkharka airport (Khotang) brought in operation.

2004: Domestic operation by jet aircraft commenced.

2005: International flights by two private operators began.

2006: A new comprehensive Aviation Policy introduced. GMG Airlines of Bangladesh, Korean Air and Air Arabia started air service to Nepal.

Nepal has so far reached air service agreement and MoUs with more than 35 countries. Austria, Bahrain, Bangladesh,

Bhutan, Brunei, China, Croatia, Egypt, France, Germany, Hong Kong, India, Israel, Italy, Japan, Jordan, Kuwait,

Luxembourg, Macau, Malaysia, Maldives, Myanmar, Oman, Pakistan, Philippines, Qatar, Republic of Korea, Russian

federation, Saudi Arabia, Singapore, Sri Lanka, Thailand, The Netherlands, United Arab Emirates, United Kingdom.

In domestic service the airlines in the table are mainly functioning in different airports of Nepal. Civil Aviation Authority of

Nepal has granted Air Operation Certificates more than thirty airline companies for scheduled/chartered operation, helicopter

services and paragliding.


4. Some organizations related to the civil aviation:

International Civil Aviation organization-ICAO o Established in 1944 as a result of Chicago convention Headquarter is in Montreal, Canada. o It is made up of an assembly, a council of limited membership with various subordinate bodies and a

secretariat. o Assembly composed of representatives from all contracting states, is the sovereign body of ICAO o The council the governing body which is elected by the assembly for a three year term is composed of 36

states. o ICAO aims and objectives are to develop the principles and techniques of international air navigation and

to foster the planning and development of international air transport so as to Insure the safe and orderly growth of international civil aviation throughout the world.


Encourage the arts of aircraft design and operation for peaceful purposes Encourage the development of airways, airports, and air navigation facilities for international civil

aviation Meet the needs of the peoples of the world for safe, regular, efficient and economical air transport.

o Strategic objectives for the period of 2005-2010: Safety Security Environmental protection Efficiency Continuity Rule of law

Federal Aviation Agency-FAA

Civil Aviation Authority of Nepal-CAAN

Airport Authority of India 5. Classification of Airports: There are different classifications by the related organizations such as ICAO, FAA etc.

5.1. Based on take-off and landing o Conventional take-off and landing airport (runway length > 1500 m. o Reduced take-off and landing airport (runway length 1000 to 1500m) o Short take-off and landing airport (runway length 500 to 1000m) o Vertical take-off and landing airport (operational area 25 to 50 sq. m.)

5.2. Based on the Geometric design (ICAO) o It employs aerodrome reference code, it consists of length of runway available

Classified using code number 1 through 4 o Aircraft wing span and outer main gear wheel span

Classified using letters A through E o ICAO classification based on wing span and outer main gear wheel span


5.3. Based on function:

Civil aviation airports o Domestic airports o International airports o Combination of international and domestic

5.4. Military aviation airports


6. Airlines frequency at different airports of Nepal:

7. Aircraft Component parts

7.1. Engine

7.2. Propeller

7.3. Fuselage

7.4. Three control

7.5. Tricycle under carriage


8.1 Engine

Engine is required to provide the force for propelling the aircraft through the air. According to the method of propulsion

aircraft engine can be classified as:

1. Piston engine: It is powered by gasoline fed reciprocating engine and is driven by propeller or airscrew. Engine

rotates a shaft with a considerable amount of torque. Propeller is mounted on the shaft to absorb the torque.

Rotating propeller attains its rated speed, huge masses of air is hurled rearwards thereby pulling the aircraft forward

and creating lift on the wing. They are suitable to operate at low altitudes and moderate speed. They have cooling

problem also.

2. Jet engine: advantages of jet engine

a. they are free from vibration

b. Simplicity of operation (no transmission or conversion mechanism is required)

c. No radiators required

d. No spark plugs are required

e. No carburetors

f. Less consumption of lubricants

i) Turbo Jet: to start the machine, the compressor is rotated with motor. As the compressor gains its rated speed,

it sucks in air through the air intake and compresses it in the compression chamber. The air is ignited here by

fuel. The expanding gasses pass through the fan like blades of turbine. The hot gasses escape through the tail

pipe which becomes smaller in diameter and this hot gas having velocity, give a forward thrust to the engine.

ii) Turbo Prop: It is similar to the turbo jet engine except that propeller is provided in it. Turbine extracts enough

power to drive both the compressor and propeller.


iii) Ram Jet: It has no moving parts. It must be operated at high speed It requires the assistance of other types of

power plant to reach the operating speed. The heated air expands and rushes out of the exhaust nozzle at

high velocity creating jet thrust.

3. Rocket engine: It produces thrust in the same way as the ram jet engine except it does not depen upon the

atmospheric oxygen. There is no limit on altitude.

An airplane can be single engine or multi engined. Single engine usually mounted at the nose of the fuselage. In two or four

engined aircraft they usually housed in the leading edge of the aircraft.

8.2 Fuselage:

It is main body of the aircraft and provides space for the power plant, fuel, cockpit, passenger, cargo etc.

8.3 Wings:

Wings are required to support the machine in the air, when the engine has given forward speed.

8.4 Three controls:

There are three axes about which an aircraft in space may move to control these movements an aircraft is provided with

three principal controls:

PCos

PSin


i) Elevator: elevator consists of two flaps capable of moving up and down through an angle of 50-60 degree. They

are hinged to a fixed horizontal surface at the extreme rear end of fuselage. It controls the pitch of the aircraft.

ii) Rudder: It consists of a flap hinged to a vertical line provided at the tail end of fuselage. It is utilized for turning

(or yawing) movement of the aircraft. It works just a boat is steered in water.

iii) Aileron: it is hinged flap in the trailing edge of the wing. It is for rolling movement control.

X axis: rolling movement; Y axis: Pitching; Z axis: Yawing

8.5 Tricycle under-carriage:

Tricycle undercarriage if for supporting the aircraft while it is in contact with the ground. Functions:

To absorb landing shocks

To enable the aircraft to maneuver on the ground

Types:

Single wheel assembly

Dual wheel assembly

Dual wheel assembly in Tandem


9. Aircraft Characteristics:

1. Engine type and propulsion

2. Size of aircraft

3. Minimum turning radius

4. Minimum circling radius

5. Speed of aircraft

6. Capacity of the aircraft

7. Aircraft weight & wheel configuration

8. Jet Blast

9. Fuel spillage

10. Noise

9.1 Size:


Aircraft type Wing

span, m

Length,

m

Maximum

weight at

take off, kg

Wheel

track, m

Wheel base,

m

Height,

m

Cruising

speed,

km/ph

Boeing 747 59.6 70.5 351500 11 25.6 19.3 940

Boeing 737 28.3 30.5 45600 5.3 11.4 11.3 850

Air bus 300 44.8 53.8 152000 9.6 18.6 16.6 900


9.2 Make a figure of Minimum turning radius:

9.3 Minimum Circling Radius in Space:

Small general aviation aircraft: 1.6 Km

Two piston aircraft: 3.2 km

Jet engine (IFR): 80 km

9.4 Capacity of aircraft:

baggage, cargo, and fuel accommodated in the aircraft.

9.5 Takeoff and landing distance:

Factors affecting: gradient of runway, direction and intensity of wind, temperature, altitude, weight of aircraft etc.


areawingaircraftoftGrossweighWL

= where, WL is wing loading

engineofHPTotalaircraftoftGrossweighPL

= Where, PL is power loading

9.6 Speed of aircraft:

Ground speed or cruised speed, air speed (relative to air)

9.7 Weight of air craft and wheel configuration:

These are important for the design of Runway strength, taxiway, apron and hanger etc.

9.8 Jet Blast:

At relatively high velocities the aircraft eject hot exhaust gases. It may affect the bituminous pavement, cause uncomfort

to the passenger. Jet Blast deflector or fences could be constructed.

9.9 Fuel Spillage

At loading aprons and hangers, it is difficult to avoid spillage completely.

9.10 Noise:

Noise affects to the surrounding communities.

10. Aviation System Planning

Aviation system planning is a process aimed at translating goals and policies into programs that would guide the evolution of

the aviation system. The process is a continuing one and it includes monitoring of the development of the system and the

replanting of its evolution. The aviation system planning process can be applied to planning national and statewide aviation

system as well as components of such system as in the case of airport planning.

Components of the aviation system:

Airways

Airports

Airlines

Aircrafts

General aviation

Air passenger

Operating environment

Airport system planning, however, frequently has to be carried out as part of the exercise of master planning at one or more

airports within the system.

The aim of the airport system planning is to determine and plan for the scope of development of individual airports within a

system in accordance with a scheme which is most likely to fit the individual facilities into an optimal overall development

pattern.


Level of planning:

Strategic planning examines long-term structures and determines how well various structures fit with indentified

goals and objectives. A strategic plan sets out procedure to follow which will lead to an optimal long term structure.

Tactical Planning: determines short-term and medium term courses of action which best fit into overall strategic

plans and goals. Furthermore, tactical plans identify the best manner of carrying out these short and medium term

courses of action.

Levels Activities Planning

Strategic planning Level

Sets goals and objectives

Inventory of existing strategic system

Demand analysis

Postulate options or scenarios

Evaluation

Selection of future strategic system

(aviation systems planning)

Strategic planning Level

Inventory of existing system

Scenario and demand analysis

Postulate options for the system development

Evaluation

Select optimal airport system

Airport system

Planning

For each airport facility

Strategic and tactical

Planning level

Inventory of facilities

Demand analysis

Airport development options

Option evaluations

Select preferred option

Airport master

planning

Tactical and project planning

level

Select individual project

Propose different project planning options

Select preferred project plan

Optimize execution of project

Project planning

10.1 Data base for airport system Planning:

Traffic data:

o Route and city pair specific data, including origin/destination flows.

o Airport specific data

o Traffic by other modes especially in short haul situations.

Demand characteristics

o Origin destination demand

o Trip purpose distributions for cargo demands

o Commodity classifications for cargo demands

o General aviation activity demand


Airport data

o Financial results

o Facilities inventories

o Capacity

o Temporal traffic patterns, including hourly distributions

o Airlines served

o Access traffic conditions

o Safety records

o Weather conditions

o Traffic operation patterns

Supply data

o City pair available capacity

o Schedule and fares for passengers and cargo

o Load factor prevailing

o Airline operating cost data

Socio economic data

o Economic studies for regional economic plans if available

o Population and demographic characteristics and forecasts, if available

o Income characteristics and consumption patterns

o Foreign and tourism trade patterns


10.2 Comprehensive Airport system analysis


10.3 Airport Master Plan

The planner's idealized concept of the form and structure of the ultimate development of the airport is contained in the airport

master plan. This plan is not only the physical form of the ultimate development plan but a description of the staging of

development and both the financial implications and fiscal strategies involved. Master Planning applies to the construction of

new airport as well as to the significant expansion of existing facilities.

Specific objectives of airport Master Plan:

1. Provide effective graphic representation of the future development of airport and future lan-use in the

vicinity of the airport.

2. Establish a realistic schedule for the implementation of the development proposed in the plan,

particularly for short term capital implement program.

3. Proposing an achievable financial plan to support the scheduled implementation program.

4. Justifying the plan technically and procedurally through a thorough investigation of concepts and

options of a technical, economic, or environmental nature.

5. Presenting for public consideration in a convincing candid manner, a plan which adequately addresses

the issues and satisfies local and national regulations.

6. Documenting policies and future aeronautical demand and reference in municipal deliberations on

spending, debt incurrence and land use controls.

7. Setting the stage and establishing the framework for a continuing planning process. Such process

would monitor key conditions and adjust plan recommendations if required by changed circumstances.

10.4 Elements of Master Plan:

The FAA specifies a number of elements which are generally to be included in any master planning exercise:

1. Organization and preplanning

2. Inventory of existing conditions and issues

3. Aviation demand forecasting

4. Requirement analysis and concept development

5. Airport site selection

6. Environmental procedure and analysis

7. Simulation

8. Airport plans

9. Plan implementation


10.5 Steps of Master Plan ICAO:

1. Prepare a master work plan

2. Inventory and document of existing conditions

3. Forecast the future air traffic demand

4. Determine scale and time phasing of facilities

5. Evaluate existing and potential constraints

6. Determine the relative importance of constraints and other considerations.

7. Develop a number of master plan options

8. Evaluate and screen all plan options

9. Select the most acceptable and appropriate option, refining and modifying it in response to the

evaluation process

10. Prepare master plan documents in final form.

11. Airport Site Selection

Suitable site for airport depends upon the class of the airport. Factors to be considered for a suitable airport site are:

1. Consistency with Regional plan

2. Operational capability: airspace considerations, obstructions, weather etc.

3. Airport use: military, civil, etc.

4. Proximity to other airport: minimum spacing between two airports:

Airport for general aviation under VFR 3.2 km

For two piston aircraft VFR: 6.4 km

Piston engine IFR: 25.6 km

Jet engine aircraft: 160 km.

5. Ground accessibility: normally it should not exceed 30 minute drive form the city. It is desirable to locate airport

adjacent to the highway.

6. Topography: hill top is most suitable

7. Visibility: free from fog, smoke haze etc.

8. Wind: runway orientation should be: landing and takeoff is done by heading into wind. Smoke from city and industry

should not blow over the airport.

9. Noise nuisance: landing and takeoff path should not pas over the residential or industrial areas.

10. Grading, drainage and soil characteristics

11. Future development

12. availabilities of utilities from town

13. economic considerations

12. Predicting air travel demand

In any travel mode, which demand is continuously increasing at a significant rate, an estimate of the magnitude of demand at

future points in time is essential. However, the forecasting of future demand is a difficult and uncertain procedure, and when

forecasts are incorrect, an entire transportation mode is either deficit in its ability to provide for future traffic or is suffering


from overinvestment and poor economic performance. In spite of the difficulties associated with making forecasts of air

transport demand, such estimates are necessary, for the following reasons:

a) To assist manufacturers in industry to anticipate levels of aircraft orders and to develop new aircraft.

b) To aid airlines in their long-run planning for both equipment and personnel.

c) To assist governments to facilitate the orderly development of the national and international airways system, and to

aid all levels of government in the planning o f infrastructure facilities, runways, taxiways, aprons and technical air

traffic control.

Figure 1 Total world passenger Traffic

Accurate forecast of air passenger and freight demand proved to be extraordinary difficult in the past, when over an extended

period rapid advances in technology continued to lower the real costs of air transport to consumer. During the period 1972-

1987, as shown in the figure, the overall world growth of scheduled passenger kilometer was at an average rate of 7.6%.

Asia and the Pacific demonstrate higher than average rates, and Africa lower than average rate.


Figure 2 Regional air passenger growth

12.1 Conventional methods of forecasting

Conventionally, forecasting of future air traffic demand has been carried out at the macroscopic scale, viewing demand as a

response to the overall levels of change of one or more variables. These very simple methods have been applied with

reasonable success at the local, national, and international levels, in cases where rates of growth of traffic have been

remarkably constant over time. Methods that have been used include judgment, surveys of expectation, trend forecasting,

and base forecasting, which we now consider in turn.

Judgment: under the conditions of very limited growth, a crude but effective method of forecasting is the judgment estimate

by a forecaster who is close to the problem and is able to integrate and balance the factors involved in the specific situations.

The chances of success diminish as the complexity of the situation increases and need for long term a forecast

predominates. Use of judgment can easily result in forecasting by feeling, a procedure that is abhorrent to analytical

planners.


Surveys of expectation: It is not very widely used in the survey of expectation, directed to individuals in the air transport

industry who might be said to be in a position to judge future trends. By selection of broad range of interests in the selection

of those surveyed, the forecaster hopes for a balanced view. A refined procedure, which has become more widely used in

general transportation planning, is Delphi analysis-approaching the estimate of future by applying an iterative procedure to

survey of expectation. In this procedure, experts make forecasts and then receive a feedback of results from the entire from

the entire group of forecasters. After each iteration, the range of responses tends to narrow and consensus is ultimately

reached. In general, however, surveys of expectation are more suitable to aggregate forecasts at the regional or national

levels than to disaggregate estimates at the airport level.

Trend forecasting: extensive use has been made of trend forecasting, in which the planner simply extrapolates, basing

judgment on past growth figures. In short term, this technique is reasonably reliable, especially when the extrapolation

procedure is carried out with modified growth rates to account for short term disturbances in secular trends. In long term, this

type of extrapolation is likely to be most unreliable and is theoretically difficult to substantiate. Early trends forecasts were

straight line extrapolations that were almost always too low in the rapid growth years of 1950s and early 1960s. Forecasts

over the next 10 years, that is, 1960-1970 were of an exponential nature, but opinion is now more conservative, reflecting an

industry consensus that curve of growth is more likely to be logistic as in the figure below.

Figure 3 The logistic growth curve

Base forecasts on ratios of National forecasts: In USA, a technique for air traffic forecasting widely used at the local level is

the base forecast method, which assumes that a city's percentage of annual national passenger volumes remain relatively

constant over time. Airport forecasts are obtained by step down percentages of national forecasts. However, it has serious

limitations:


Percentages of national growth does not remain constant;

National forecasts have been historically incorrect,

There are two methods used in USA:

Method A:

1) Determine the percentage of national enplaned passenger that the airport has attracted in the past.

2) Adjust this percentage to reflect anticipated abnormal growth trends

3) Obtain data for national passenger volume for the design year

4) Calculate step down design figure as the product of the percentage of step 2 and the national figure from step 3.

Method B

1) Obtain the number of passenger per 1000 population that the airport has experienced in the past.

2) Compare the figure computed in step 1 with the number of passengers nationally per 1000 population.

3) Compute the following ration:

nation 1000/airport 1000/

forpopulationpassengersforpopulationpassengers

r =

4) Obtain the national forecast of air passenger volumes per 1000 population for the design year.

5) From the ratio computed in step 3 and the national forecasts of step 4, calculate the local passenger volume per

1000 population.

12.2 Analytical methods of air travel demand forecasting

Analytical methods endeavor to overcome the grosser errors of trend analysis in trip generation by attempting to relate the

level of traffic to change in the level of a variety of causal or closely associated factors. In the case of air traffic demand, it

has been found that the number of trips made by the individual traveler depends not only on a number of socioeconomic

variables outside the air transport system, such as income, employment type, and family structure, but also on system based

variables, including frequency and level of service. Conventional analysis of traffic demand divides the modeling procedure

into four distinct consecutive steps:

Generation Distribution Modal choice Assignment


Generation models indicate how many trips originate or terminate in a specific area; these models are often based on the

socioeconomic characteristics of the area and nature of the transportation system. In the distribution phase, the trips are

modeled as trip interchanges between specific pairs of origin and destinations, usually using some form of equilibrium model,

with time or distance as the parametric impedance to travel.

Modal choice models split the interchanges into those specific to individual modes; choice normally is a function of structure

and nature of the transport system and the socioeconomic status of the trip maker. Assignment models indicate which route

is taken by the individual traveler from a choice of all available routes.

In case of air transport, the model chain has frequently been simplified to a mode specific chain of the following from:

Air trip generation Air trip distribution

This simplified chain is inadequate insofar as it assumes that air traffic generations are peculiar to the mode itself and are not

subject to modal choice dependent on the nature of the competing modes.

Variables for passenger demand modeling:

Travel can be recognized as the product of four basic factors that must be accounted for in any realistic analysis that

attempting to predict demand over time. These basic factors are as follows:

A supply of people

A motivation to travel

Resources available for expenditure on travel in terms of time and money

A transport infrastructure capable of supporting travel demand

The procedure should consist the following steps for complete demand analysis:

1) Observation of past trends

2) Identification of exogenous variables that act as surrogate for basic factors causing changes in level of air transport

demand.

3) A base survey collecting the socioeconomic data that describe the status of the population, nature of the area, and

the technological status of the system.

4) Establishment of relationships between the predictive variables and both levels and changes in levels of air

transport demand.

5) Prediction of the anticipated level of the exogenous variables in the design year

6) Prediction from the design year levels of the exogenous variables and predictive relationships of the future demand

levels.

The simplistic methods of prediction, such as trend forecasting, take explicit account of the first step only, and steps 2 and 6

are mixed with subjective judgment, with varying degrees of success.

In the past, variables in the following areas have been used:

1) Demographic variables. Including city size and population density

2) Proximity to the largest city

3) Economic character of the city


4) Governmental activities, regulatory policies, subsidy of competing modes etc.

5) Fare levels

6) Developments in competing transport modes

7) Technological development in the aircraft industry

8) Adequacy of infrastructure provision of the air mode and competing modes

9) Urban and regional development characteristics

10) Various other imponderables (not able to be estimated) such as socio-cultural changes in the leisure and work

pattern etc

12.3 Air trip generation models

The analyst models directly the number of trips ends (origins and destinations). There are two principle techniques of

analysis: market analysis and regression analysis.

Market analysis: it assumes that an areas share of the total market remains constant over time. National demands total are

estimated for the design date usually by using straight forward trend forecasting or cross classification.

Regression analysis: statistical models for the demand analysis have been widely used for many years in the prediction of

urban passenger transport.

12.4 Air trip distribution models

The trip distribution models predicts the level of trip interchange between designated airport pairs, once the level of

generation of air trip ends at the individual airports have been the gravity model. This model analog to the Newton's law of

gravity, has grown from the knowledge developed in social sciences that interaction between human settlements appear to e

in accord with principles that in many similar to the physical law of gravity. The gravity model in transport practice distributes


trips between city pairs according to measures of the attractiveness of cities, allowing for the impedance effects of cost, time

and other facts.

x

ij

jiij d

PkPT =

Where, Tij - is travel by air passenger between cities I and j

Pi - population of origin city

Pj Population of destination city

dij distance between city i and j

k a constant of proportionality

x a calibrated constant

Using as the measure of the impedance, it was found that the value of x appeared to vary from 1.3 to 1.8. using the travel

cost, the following model was calibrated:

x

ij

jiij C

TkTT =

Where, Ti Total air trips generated in city i

Tj - total air trips attracted in city j

Cij cost of travel between i and j

K a constant of proportionality

X - a calibrated proportionality

In US studies airline interaction traffic, it was found that this model could be used for cities less than 800 miles apart. For

greater air trip degenerated air trip distances, the form of the model can be simplified:

pjiij TTkT )(=

A modified gravity model was used in Canada:


A predictive equation of a similar form was developed by former British Airport Authority for the Western European Airports

Association was:


12.5 Modal choice models

As previously stated, the analytical forecasting method has frequently been used to mode-specific air trip generation that has

been separately distributed. Many factors affect modal choice, such as convenience, comfort, and safety. Though such

factors are often difficult to quantify, a simple method of allowing for them and for individual variability among travelers is to

construct the model from parameter that reflect the degree of randomness of the traveler's choice. The generalize dcost

model assumes that the traveler will usually choose the mode with the lowest generalized cost, but there is a finite probability

that some other mode will be selected.

The generalized cost of any mode is the total of direct and indirect costs incurred in traveling. If there are only two alternative

modes p and q then above equation is reduced as:


13. Airport Capacity

The growth in air travel is outstripping the capacity of airport and air traffic control system, resulting in

increasing congestion and delay. The consequences for the air transport industry and traveling public are

greater inconvenience, higher costs, declining quality of services and concerns about diminishing safety. The

purpose of capacity analysis is to:

Measure objectively the capacity of various components of an airport system for handling projected

passenger and aircraft flows.

Estimate the delays experienced in the system at different levels of demand.

The capacity analyses make it possible for the airport planner to determine the number of runways, to identify

potential configurations, and to compare alternative design.

13.1 Capacity, Demand and Delay

The term "capacity" refers to the ability of a component of airfield to accommodate aircraft. It is expressed in

operations (arrivals and departures) per unit of time, typically in operations per hours. Thus, the hourly

capacity of the runway system is the maximum number of aircraft operations that can be accommodated in

one hour under specified operating conditions. Capacity depends on a number of prevailing conditions, such as

visibility, air traffic control, aircraft mix, and type of operations.

Capacity should not be confused with demand. Capacity refers to the physical capability of an airfield and its

components. It is measure of supply, and it is independent of both the magnitude and fluctuation of demand

and the amount of delay to aircraft. Delay, however is dependent on capacity and the magnitude and

fluctuation in demand. One can reduce aircraft delays by increasing capacity and providing a more uniform

pattern of demand.


13.2 Runway capacity

Runway capacity is normally the controlling element of the airport system capacity. There are large numbers of

factors that influence the capacity of runway system:

1) Air traffic control: FAA specifies minimum vertical, horizontal, and lateral separations for aircraft in the

interests of air safety. Since no two airplanes are allowed on the runway at the same time, the runway

occupancy time may also influence the capacity.

Example: A runway serves aircraft that land a speed at 165 mph while maintaining the minimum

separation of 3 nautical miles as specified by FAA. The average runway occupancy time for landing

aircraft is 25 seconds. Determine maximum arrival rate pf the airport. The minimum spacing is (3X6076

= 18228 ft.) in terms of time the minimum arrival spacing is 18228 /(165X5280/3600)= 75 sec. The

maximum rate of arrival that can be served by the runway is no more than (3600/75) = 48 arrivals per

hour.

2) Characteristics of demand: capacity of runway depends on aircraft size, speed, maneuverability, and

braking capability, as well as pilot technique.

3) Environmental conditions: the most important environmental factors influencing capacity are visibility,

runway surface conditions, winds, and noise abatement requirements.

4) The layout and design of runway system: for the airport planner, layout and design features comprise

the most important class of factors that affect runway capacity. Principal factors in this class include:

Number, spacing, length and orientation of runways.

The number, locations, and design of exit taxiway

The design of ramp entrance


13.3 Determination of runway capacities and delay

a) Empirical approaches

b) Queuing models

c) Analytical approaches

d) Computer simulation


Table of Contents 1. Airport Layout .................................................................................................................................................. 47

2. Runway Orientation: ......................................................................................................................................... 47

3. Typical Layout of Airport ................................................................................................................................... 53

4. Geometric Standards for Elements of Airport ...................................................................................................... 54

5. Correction for Elevation, Temperature and Gradient ............................................................................................ 58

6. Taxiway and Apron .......................................................................................................................................... 63

7. Holding bays and other bypasses ...................................................................................................................... 70

8. Apron .............................................................................................................................................................. 71

9. Terminal Facilities & Space ............................................................................................................................... 77

10. Air traffic management ...................................................................................................................................... 83

11. CNS/ATM System ............................................................................................................................................ 86

12. References ...................................................................................................................................................... 90


1. Airport Layout The design for each airport layout is site specific, and whereas general concepts can be moved between sites, the individual

aspects of each site will almost certainly result in slightly different layouts. Layout of an airport is dependent upon a number

of factors the most important are:

1. Number and orientation of runways 2. Number of taxiways 3. Size and shape of aprons 4. The area and shape of land 5. Topography and site soil conditions 6. Obstacle to air navigation 7. Required proximity of land uses within the airport boundary 8. Surrounding land uses 9. Timing and scale of phased development of the airport 10. Meteorology 11. Size and scale of airport facilities being planned

Principle facilities to be considered in an airport plan are:

1. Runways 2. Taxiways 3. Passenger terminal and aprons 4. Cargo terminal and apron 5. Rescue and firefighting services 6. Air traffic control tower 7. Aircraft maintenance 8. Long-term and short-term parking 9. Access roads 10. Public transport access 11. Airport maintenance and engineering base 12. Navaids 13. Lighting 14. Flight kitchens 15. Fuel farm 16. General aviation terminal and apron 17. Sewage treatment and pumping station 18. Electric sub-station 19. Security fence and control gates 20. Hotels 21. Industrial uses

2. Runway Orientation: Because of obvious advantages of landing and taking off into the wind, runways are oriented in the direction of prevailing wind. Aircraft

may not maneuver safely on a runway when wind contains large component at right angle to the direction of travel. The point at which this

component (cross wind component) becomes excessive will depend upon the size and operating characteristics of the aircraft.


Figure 4 Maximum permissible Cross Wind Component (FAA)

Factors affecting the determination of the siting, orientation and number of runways:

weather, in particular the runway/aerodrome usability factor, as determined by wind distribution, and the occurrence of localized fogs;

topography of the aerodrome site and its surroundings;

type and amount of air traffic to be served, including air traffic control aspects;

aeroplane performance considerations; and

environmental considerations, particularly noise.

The primary runway, to the extent other factors permit, should be oriented in the direction of the prevailing wind. All runways should be

oriented so that approach and departure areas are free of obstacles and, preferably, so that aircraft are not directed over populated

areas.

Figure 5 Maximum permissible CWC (ICAO)

Head wind: direction of wind opposite to the direction of landing and takeoff

Takeoff: head wind provides greater lift on the wings, thus shorter length of runway is enough

Landing: Headway provides a braking effect and aircraft comes to stop in a smaller length of runway.


If landing and takeoff are done along the wind direction, it may require longer runway length.

Cross wind Component: it is not always possible to obtain the direction of wind along the direction of the center line of

runway, this Normal wind component is called cross wind component. And it may interrupt the safe landing and takeoff of

the aircraft. VSin is the Cross wind Component.

Wind Coverage: The percentage of time in a year during which the CWC remains within the limit is called Wind Coverage.

FAA standards for mixed air traffic wind coverage should be 95 % with the limit of 25 kmph. CWC.

For busy airport, WC may be 98 -100 %

Wind Rose method:

Typically wind rose is applied for the orientation of runway.

Wind Rose type I: It is the graphical representation of wind data: direction and intensity. Data should be collected for the

period of 5 to 10 years. Wind data average of 8 years period

Wind direction Duration, % Total in each

direction, % 6.4 -25 kmph 25 40 kmph 40 60 kmph

N 7.4 2.7 0.2 10.3

NNE 5.7 2.1 0.3 8,1

NE 2.4 0.9 0.6 3.9

ENE 1.2 0.4 0.2 1.8

E 0.8 0.2 0.0 1.0

ESE 0.3 0.1 0.0 0.4


SE 4.3 2.8 0.0 7.1

SSE 5.5 3.2 0.0 8.7

S 9.7 4.6 0.0 14.3

SSW 6.3 3.2 0.5 10.0

SW 3.6 1.8 0.3 5.7

WSW 1.0 0.5 0.1 1.6

W 0.4 0.1 0.0 0.5

WNW 0.2 0.1 0.0 0.3

NW 5.3 1.9 0.0 7.2

NNW 4.0 1.3 0.3 5.6

Total % = 86.5

(100 - 86.5 ) = 13.5 % of time wind intensity is less than 6.4 kmph. This period is called Calm Period.


Wind Rose type II

In this method a transparent template is prepared for determining the runway orientation.

The wind data shown in the table are plotted on a wind rose by replacing the percentage in the appropriate segment of

graph. On the wind rose, the circles represent wind velocity in miles per hour and the radial lines indicate wind direction.

The wind rose procedure makes use of a transparent template on which three parallel lines have been plotted. The middle

line represents the runway center line, and the distance between it and each of the outside lines is equal to the cross wind

component.


Figure 6 Wind rose diagram for an allowable cross wind of 15 miles per hour

Following steps are necessary to determine the best runway orientation and to determine the percentage of time that

orientation conforms to the cross wind standards.

a) Place the template on the rose so that the middle line passes through the center of the wind rose. b) Using the center of wind rose as a pivot, rotate the template until the sum of the percentage between the outside

lines is a maximum. c) Read the true bearing for the runway on the outer scale of the wind rose beneath the centre line of the template. d) The sum of percentage between the outside lines indicates the percentage of time that a runway with the proposed

orientation will conform to crosswind standards.


3. Typical Layout of Airport


4. Geometric Standards for Elements of Airport Standards are for:

1. Runway 2. Taxiway 3. Apron

1. Runway

Parameters of runway are:

i) Length ii) Width iii) Sight distance iv) Gradient & Change in Gradient v) Transverse Gradient Runway Intersection vi) Runway Clearance

Selecting design runway length is one of the most important decisions an airport designer. The runway length determines the

size and cost of the airport, and controls the types of air craft it will serve. Furthermore, it may limit the payload of the critical

aircraft and length of journey it can fly. The runway must be long enough to allow safe landing and takeoff by current

equipment and by future aircraft expected to use the airport. It must accommodate differences in pilot skill and variety of

aircraft types and operational requirements.

The following factors most strongly influence required runway length.

a) Performance characteristics of aircraft using runway length. b) Landing and takeoff gross weights of aircraft c) Elevation of airport d) Average maximum air temperature at the airport e) Runway gradient

Note:

Correction for elevation and temperature should be done

Maximum width of landing strip: o Non instrumental runway: 150 m o Instrumental runway: 300 m

Actual length of Runways

Primary runways:

Except where a runway is associated with a stopway and/or clearway, the actual runway length to be provided for primary

runway should be adequate to meet the operational requirements of the aeroplanes for which the runway is intended and


should be less than the longest determined by applying the corrections for local conditions to the operations and performance

characteristics of the relevant aeroplanes.

Both takeoff and landing requirements need to be considered when determining the length of runway to be provided and

need for operations to be conducted in both directions of runway. Local conditions that may need to be considered include

elevation, temperature, runway slope, and the runway surface characteristics.

Secondary runways:

The length of secondary runway should be determined similarly to primary runways except that it needs only to be adequate

for those aeroplanes which require using that secondary runway in addition to the other runway or runways in order to obtain

a usability factor of at least 95 percent.

Runways with stopways and/or clearways:

When runway is associated with a stoway or clearway, an actual runway length less than that resulting from application of

(primary and secondary runways) as appropriate, may be considered satisfactory, but in such a case any combination of

runway, stopways or clearway provided.

Basic length of runway characte

It is the length of runway under the following conditions:

Airport altitude is at sea level

Airport temperature is 15 0 Celsius

Runway is level in longitudinal direction

No wind is blowing on runway

Aircraft is loaded to its full capacity.

Declared distances

The introduction of stopways and clearways and the use of displaced thresholds on runways has created a need for accurate

information regarding the various physical distances available and suitable for the landing and takeoff of airplanes.

a) Take-off run available (TORA): the length of runway declared available and suitable for the ground run off an aero plane taking off.


b) Take off distance available (TODA): the length of takeoff run available plus the length of the clearway, if provided.

c) Accelerate stop distance available (ASDA): the length of the take-off run available plus the length of the stopway, if provided.


d) Landing distance available (LDA): the length of runway which is declared available and suitable for ground run of an airoplane landing.

1. When a runway is not provided with stopway or clearway and threshold is located at the extremity of the runway, the four declared distances should be equal to the length of the runway as in figure A.

2. Where runway is provided with clearway, then the TODA will include the length of clearway as in figure B. 3. When runway is provided with a stopway, then the ASDA will include the length of stopway as in figure C. 4. Where a runway has a displaced threshold, then the LDA will be reduced by the distance the threshold is displaced

as in figure D.


Figure 7 Declared distances

5. Correction for Elevation, Temperature and Gradient Basic length of runway is for mean sea level, having standard atmospheric conditions. It is necessary to carry out corrections

for elevation, Temperature and Gradient

a) Correction for Elevation As the elevation increases, the air density reduces. It reduces the lift on the wing of the aircraft and aircraft requires greater

ground speed before it can rise into the air. To achieve greater speed longer length of runway is required. ICAO recommends

that the basic runway length should be increased at the rate of 7% per 300 m rise in elevation above mean sea level.

Correction for temperature

The rise in airport reference temperature has the same effect as that of the increase in elevation. Airport reference

temperature (Tr) is defined as the monthly mean of average daily temperature (Ta) for the hottest month of the year plus one

third the difference of this temperature (Ta) and monthly mean of the maximum daily temperature (Tm) for the same month of

the year.


3am

ar

TTTT

+=

ICAO recommends that the basic length of the runway after having been corrected for elevation should be further increased

at the rate of 1 % for every 1o rise of airport reference temperature above the standard atmospheric temperature (Ts) at the

elevation. The temperature gradient of the standard atmospheric from the mean sea level to the altitude at which temperature

becomes 15 o C is -0.0065 o C per meter.

Check for total correction for elevation and temperature:

It the total correction (elevation and temperature) exceeds 35% the basic runway length, these corrections should then be

checked up by conducting specific studies.

b) Correction for Gradient Steeper gradient results in greater consumption of energy, and longer the runway length is required for attaining the ground

speed.

ICAO does not recommend on this correction. FAA recommends that the runway length after having been corrected for

elevation and temperature should be further increased at the rate of 20% for every 1% of effective gradient.

Effective gradient is defined as the maximum difference in elevation between the highest and lowest points of runway divided

by the total length of runway.

ii) Width of Runway

The width of a runway should not be less than the approximate dimension specified in the table below. The factors affecting

the width of runway are:

a) Deviation of an aeroplane from the centerline at touchdown. b) Cross wind condition c) Runway surface contamination (snow, rainfall ice etc.) d) Rubber deposit e) Crab landing approached used in cross-wind conditions f) Approach speeds used g) Visibility h) Human factors


Longitudinal slopes:

The slopes computed by dividing the differences between the maximum and minimum elevation along the runway centerline

by the runway length should not exceed:

1 % where the code number is 3 or 4

2% where the code number is 1 or 2 Along no portion of a runway should the longitudinal slope exceed:

1.25% where the code number is 4, except that for the first and last quarter of the length of the runway the longitudinal slope should not exceed 0.8%.

1.5 % where the code number is 3, except that the first and last quarter of the length of a precision approach runway II or III the longitudinal slope should not exceed 0.8%.

2 % where the code number is 1 or 2. Longitudinal slope changes

Where slope changes cannot be avoided, a slope change between two consecutive slopes should not exceed:

1.5 % where code number is 3 or 4;

2% where code number is 1 or 2 The transition from one slope to another should be accomplished by a curved surface with a rate of change not exceeding:

0.1 % per 30 m. (R min of 30 000) where code number is 4

0.2% per 30 m ( R min 15 000) where code number is 3.

0.4% per 30 m (R min 7 500) where code number is 1 or 2.

Sight distance

Where slope changes cannot be avoided, they should be such that there will be an unobstructed line of sight from:

Any three m above a runway to all other points 3 m above the runway within a distance of atleast half the length of the runway where the code letter is C, D or E;

Any point 2 m above a runway to all other points 2 m above the runway within a distance at least half the length of runway where code letter is B; and

Any point 1.5 m above a runway to all other points 1.5 m above the runway within a distance of at least half the length of runway where the code letter is A.

Distance between slope changes

Undulation or appreciable change in slopes located together along the runway should be avoided. The distance between the

points of intersection of two successive curves should not be less than:

a) The sum of the absolute numerical values of the corresponding slope changes multiplied by the appropriate values as below:

30 000 m where the code number is 4

15 000 m where the code number is 3 and

5 000 m where the code number is 1 or 2 b) 45 m;

Whichever is greater?


Figure 8 Runway visibility zone

Transverse slope

To promote the rapid drainage of water, the runway surface should, if practicable, be cambered except where a single cross

fall from high to low in the direction of the wind most frequently associated with rain would ensure rapid drainage. The

transverse slope should ideally be:

1.5 % where the code letter is C, D, E or F

2% where the code letter is A or B But in any event should not be exceed 1.5 % or 2 %. As applicable, nor be less than 1 % except at runway or taxiway

intersections where flatter slopes be necessary.

Runway shoulder

Runway shoulder must be provided to ensure a transition from the full strength pavement to the unpaved strip of runway. The

paved shoulder protects the edge of the runway pavement, contribute to the prevention of soil erosion by jet blast and


mitigate foreign object damage to jet engines. Runways shoulder should be provided for a runway where the code letter is D

or E and the runway width is less than 60m. Runway shoulders should be provided where the code letter is F.

The runway shoulders should extend symmetrically on each side of the runway so that the overall width of the runway and its

shoulders is not less than 60 m for letter E and 75 m fir code letter F.

Slopes:

The surface of the shoulder that abuts the runway should be flush with the surface of the runway and its transverse

downward slope should not exceed 2.5 %.

Runway strip:

A runway strip extends laterally to a specified distance from the runway center line, longitudinally, before the threshold, and

beyond the runway end. It provides an area clear of objects which may endanger aeroplanes. The strip includes a graded

portion which should be so prepared as to not cause the collapse of the nose gear if an aircraft should leave the runway.

There are certain limitations on the slopes permissible on graded portion of the strip.

A strip should before the threshold and before the end of the runway or stopway for a distance of at least:

60 m where the code number is 2, 3, or 4.

60 m where the code number is 1 and the runway is an instrument one;

30 m where the code number is 1 and runway is a non-instrument one. Width:

A strip including a precision approach runway shall, wherever practicable, extend laterally for a distance of at least:

150 m where the code number is 3 or 4 and;

75 m where the code number is 1 or 2. A strip including non-precision approach should extend laterally to a distance of at least:

150 m where the code number is 3 or 4;

75 m where the cod number is 1 and 2 On each side of the centerline of the runway and its extended centerline through the length of the strip

A strip including a non-instrument runway should extend, on each side of the centre line of the runway and its extended centre line

throughout the length of the strip, for a distance of at least:

75 m where the code number is 3 or 4 40 m where the code number is 2; and

30 m where the code number is 1.

Objects

An object, other than equipment or installation required for air navigation purposes, situated on a runway strip which may endanger

aeroplanes should be regarded as an obstacle and should, as far as practicable, be removed. Any equipment or installation required for

air navigation purposes which must be


located on the runway strip should be of minimum practicable mass and height, frangibly designed and mounted, and sited in such a

manner as to reduce the hazard to aircraft to a minimum.

No fixed object, other than visual aids required for air navigation purposes, shall be permitted on a runway strip:

within 77.5 m of the runway centre line of a precision approach runway category I, II or III where the code number is 3 or 4 and the code letter is F; or

within 60 m of the runway centre line of a precision approach runway category I, II or III where the code number is 3 or 4; or

within 45 m of the runway centre line of a precision approach runway category I where the code number is 1 or 2.

6. Taxiway and Apron Maximum capacity and efficiency of an aerodrome are realized only by obtaining the proper balance between the need for

runways, passenger and cargo terminals, and aircraft storage and servicing areas. These separate and distinct aerodrome

functional elements are linked by the taxiway system. The components of the taxiway system therefore serve to link the

aerodrome functions and are necessary to develop optimum aerodrome utilization

The taxiway system should be designed to minimize the restriction of aircraft movement to and from the runways and apron

areas. A properly designed system should be capable of maintaining a smooth, continuous flow of aircraft ground traffic at

the maximum practical speed with a minimum of acceleration or deceleration. This requirement ensures that the taxiway

system will operate at the highest levels of both safety and efficiency.

Planning principles of taxiway:

a) taxiway routes should connect the various aerodrome elements by the shortest distances, thus minimizing both taxiing

time and cost;

b) taxiway routes should be as simple as possible in order to avoid pilot confusion and the need for complicated instructions;

c) straight runs of pavement should be used wherever possible. Where changes in direction are necessary, curves of

adequate radii, as well as fillets or extra taxiway width, should be provided to permit taxiing at the maximum practical speed

(see Section 1.4 and Appendix 1);

d) taxiway crossings of runways and other taxiways should be avoided whenever possible in the interests of safety and to

reduce the potential for significant taxiing delays;

e) taxiway routings should have as many one-way segments as possible to minimize aircraft conflicts and delay. Taxiway

segment flows should be analysed for each configuration under which runway(s) will be used;

f) the taxiway system should be planned to maximize the useful life of each component so that future

Design criteria for taxiway are given in the table below.


Figure 9 Taxiway on apron


Figure Stages in Taxiway system development

Taxiway Curve:

Changes in direction of taxiways should be as few and small as possible. The design of the curve should be such that when

the cockpit of the aeroplane remains over the taxiway centre line markings, the clearance distance between the outer main

wheels of the aeroplane and the edge of the taxiway should not be less than those specified in the table below:


Taxiway separation distances


Rapid exit taxiways:


A rapid exit taxiway is a taxiway connected to a runway at an acute angle and designed to allow landing aeroplanes to turn

off at higher speeds than those achieved on other exit taxiways, thereby minimizing runway occupancy time.

A decision to design and construct a rapid exit taxiway is based upon analyses of existing and contemplated traffic. The main

purpose of these taxiways is to minimize aircraft runway occupancy and thus increase aerodrome capacity. When the design

peak hour traffic density is approximately less than 25 operations (landings and take-offs), the right angle exit taxiway may

suffice. The construction of this right angle exit taxiway is less expensive, and when properly located along the runway,

achieves an efficient flow of traffic.

Figure. Design of rapid exit taxiway (code no 1 and 2)

7. Holding bays and other bypasses

a) Holding bays: A defined area where aircraft can be held or bypassed. Figure 2-1 shows some examples of holding bay

configurations and Figure 2-2 gives

a detailed example of a holding bay, located at the taxi-holding position.


b) Dual taxiways. A second taxiway or a taxiway bypass to the normal parallel taxiway. Figure shows some examples.

c) Dual runway entrances. A duplication of the taxiway entrance to the runway.

Figure 10 holding bay

Figure 11 by-pass

8. Apron

An apron is a defined area intended to accommodate aircraft for purposes of loading and unloading passengers, mail or

cargo, fuelling and parking or maintenance. The apron is generally paved but may occasionally be unpaved; for example, in

some instances, a turf parking apron may be adequate for small aircraft


Types:

1. Passenger apron: The passenger terminal apron is an area designed for aircraft manoeuvring and parking that is adjacent or readily accessible to passenger terminal facilities. This area is where passengers board the aircraft from the passenger terminal. In addition to facilitating passenger movement, the passenger terminal apron is used for aircraft fuelling and maintenance as well as loading and unloading cargo, mail and baggage. Individual aircraft parking positions on the passenger terminal apron are referred to as aircraft stands.

2. Cargo terminal apron: Aircraft that carry only freight and mail may be provided a separate cargo terminal apron adjacent to a cargo terminal building. The separation of cargo and passenger aircraft is desirable because of the different types of facilities each requires both on the apron and at the terminal

3. Remote parking apron: In addition to the terminal apron, airports may require a separate parking apron where aircraft can park for extended periods.

4. Service hanger apron: A service apron is an uncovered area adjacent to an aircraft hangar on which aircraft maintenance can be performed, while a hangar apron is an area on which aircraft move into and out of a storage hangar.

5. General aviation aircraft, used for business or personal flying, require several categories of aprons to support different general aviation activities.


Figure 12 passenger terminal apron


General layout of apron:

The amount of area required for a particular apron layout depends upon the following factors:

the size and manoeuvrability characteristics of the aircraft using the apron;

the volume of traffic using the apron;

clearance requirements;

type of ingress and egress to the aircraft stand;

basic terminal layout or other airport use (see 3.3);

aircraft ground activity requirements; and

taxiways and service roads.


9. Terminal Facilities & Space Terminal area: Area other than landing, serves for other activities includes:

Terminal and operational building for managerial & operational activities

Vehicle parking area

Aircraft service Hanger

Various facilities provided in airport terminal building:

a) Passenger and baggage handling counter b) Baggage claim section c) Enquire counter d) Space for handling & processing mail, cargo etc. e) Public Telephone booth f) Waiting hall for passenger & visitors g) Toile facilities h) Restaurants & Bars i) First aid room j) General store & gift store k) Space for newspapers l) Space for airport staff m) Weather bureau n) Post office o) Bank p) Custom control q) Security & Police r) Passport control s) Airline office

Functions of the airport passenger terminal

Airport terminal constituents one of the principle elements of infrastructure cost at the airport. The passenger terminal

performs mainly three functions:

a) Change of mode: few air trips are made direct from origin to destination. By their nature, air trips are mixed mode trips, with surface access trips linked at either end to the line haul air trips. These movement patterns are accommodated by passenger circulation areas.

b) Processing: the terminal is a convenient point to carry out certain processes associated with air trip. These may include ticketing and checking in the passengers. This function of the terminal requires passenger processing space.

c) Change of movement type: although aircraft move passengers in discrete groups in what is termed "batch movements", the same passengers access the airport on an almost continuous basis, arriving and departing in small groups mainly by bus, auto, taxi and etc. the terminal therefore functions on the


departure side as a reservoir that collects passengers continuously and processes them in batches. On the arrivals side, the pattern is reverse. To perform this function, the terminal must provide passenger holding apace.

Facilities required for Passenger terminal

The terminal acts as the transfer point between the land and air side portions of the mixed mode 'air trip' made by air

passenger. The facilities can be categorized as follows:

1. Access including the land side interface The facilities include curbside loading and unloading, curbside baggage check in, shuttle services to parking lots another

terminal, and loading and unloading area.

2. Passenger processing area: The area is designated for formalities associated with processing passengers. The usual facilities include airline ticketing and

passenger check-in, baggage check-in, gate check-in, incoming and outgoing customs, immigration control, health control,

security check up, and baggage claim.

3. Passenger holding areas, A very large portion of the passenger's time at the airport is spent outside the individual processing areas. Non-processing

time, the large portion is spent in holding areas where passenger wait, in some cases with airport visitors, between periods

occupied by passing through the various processing facilities. Following facilities are required:

Passenger lounges

Passenger service areas: wash rooms, public telephone, post office, information desk, first aid, valet service, barber beauty parlours etc.

Concessions: bars, restaurants,

Observation desk and visitors lobbies: including VIP facilities

4. Internal circulation and airside interface Passenger move physically through the terminal system using the internal circulation system which should be simple to find

and follow and easy to negotiate. The airside interface is designed for secure and easy boarding of the aircraft. Internal

circulation is handled by corridors, walkways, people movers, and moving belts, ramps, tramways. Airside interface

requirements include loading facilities such as jetways, stairs, air bridges and mobile launges.

5. Airline and support areas Although airline terminals are designed primarily for airline passengers, most of whom will be quite unfamiliar with their

surroundings, the design must also cater to the needs of airline, airport, and support personnel working in terminal area.

Following facilities are required:


1. Airline offices, passenger and baggage processing stations, telecommunications, flight planning documentation, crew rest facilities, air line station administration, staff and crew toilets, rest and refreshment areas.

2. Storage for wheel chairs, 3. Airport management offices 4. Governmental office and support area for staff working in customs, immigration, health, and air ssenger and

traffic control, 5. Public address system, sign indicators and support areas flight information 6. Maintenance personnel offices and support areas, maintenance equipment storage.

6. Passenger and baggage flow

An adequately designed airport terminal is the work of a designer who understands the various flows of passengers and

baggage at a terminal. The figure below shows the typical flow of passenger and baggage.


Terminal design concepts

The design of terminal depends upon the nature of the sir traffic to be handled at an airport. The design concepts chosen is a

function of a number of factors, including the size and nature of traffic demand, number of participating airlines, the traffic

split between international and domestic, scheduled, and charter flights, access modes etc.

The most fundamental choice is that of centralized or decentralized processing. There are different terminal configurations.


Terminal Space design standards (FAA)


Level of service standards for terminal space


Simple network analysis of the enplanement of a domestic passenger

10. Air traffic management

The general objective of ATM is to enable aircraft operators to meet their planned times of departure and arrival and adhere

to their preferred flight profiles with minimum constraints and without compromising agreed levels of safety.

The ATM comprises the functions of air traffic services (ATS), airspace management (ASM) and air traffic flow management

(ATFM). The air traffic services are the primary components of ATM.

Control of air traffic was almost unknown in 1944. Today, air traffic control, flight information and alerting services, which

together comprise air traffic services, rank high among the indispensable ground support facilities which ensure the safety

and efficient operation of air traffic throughout the world.


Annex 11 to the Chicago Convention defines air traffic services and specifies the worldwide Standards and Recommended

Practices applicable in the provision of these services.

The world's airspace is divided into a series of contiguous flight information regions (FIRs) within which air traffic services are

provided.

In some cases, the flight information regions cover large oceanic areas with relatively low air traffic density, within which only

flight information service and alerting service are provided.

In other flight information regions, large portions of the airspace are controlled airspace within which air traffic control service

is provided in addition to flight information and alerting services.

Air travel must be safe and efficient; this requires, among other things, a set of internationally agreed rules of the air.

The rules which consist of general rules, visual flight rules and instrument flight rules apply without exception over the high

seas and over national territories to the extent that they do not conflict with the rules of the State being overflown. The pilot-in

command of an aircraft is responsible for compliance with the rules of the air.

All aircraft fly in accordance with either instrument flight rules (IFR) or visual flight rules (VFR). Under IFR, the aircraft fly from

one radio aid to the next or by reference to self-contained airborne navigation equipment from which the pilot can determine

the aircraft's position at all times. Aircraft flying under VFR must remain clear of cloud and operate in visibility conditions

which will permit the pilot to see and avoid other aircraft.

When operating under air traffic control the aircraft must maintain precisely the route and altitude that have been assigned to

it and keep air traffic control informed about its position.

A flight plan must be filed with air traffic services units for

Documents

Lecture notes in Airport Engineering