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    U$IT

    19 AIR TRANSPORTATIONObjectives

    S t r cture 19.1 Introduction 19.2 An Overview of Air Transportation19.2.1 19.2.2 19.2.3 19.2.4 The Origin of Air Transportation Role of Air Transport International Air Transport Today Air Transport in India

    4 I

    19.3 19.4 19.5

    Aircraft Characteristics Air Traffic Control Airport Planning and Location19.5.1 TypesofAirports 19.5.2 Complexities of Airport Planning 19.5.3 Elements of Airport Planning 19.5.4 Airport Master Plan 19.5.5 Site Selection 19.5.6 AirportSizeandCnpacity 19.5.7 ~ i $ o r t ~onstruction Cost 19.5.8 Financial Analysis

    19.5.9 Economic Analysis 19.5.10 Environmental impact-

    1

    1

    IIl

    I

    19.6 19.7

    Airport Layout Airport Pavement19.7.1 19.7.2 19.7.3 19.7.4 19.7.5 19.7.6 19.7.7 19.7.8 19.7.9 Requirements of Airport Pavement Comparison with Highway Pavement Types of Pavement Courses in an

    Airport Pavement An Overview of Design Methodology Design of Flexible Airport Pavement Design of Rigid Pavement for Airports LCN Method of Designs Overlays

    I19.8 19.9

    .

    Passenger Terminal Building Airport Facilities, Aids and Controls19.9.1 19.9.2 19.9.3 19.9.4 19.9.5 19.9.6 19.9.7 Cargo Handling Flight CateringAircr3ft Maintenance Facilities Fuelling Facilities Air ~ r & c Control Building

    Airport Lighting Radio Equipment

    II

    I

    I

    I

    I

    19.10 Heliports 19.11 STOL Ports 19.12 lllustrative Problems 19.13 Summary 19.14Keywords 19.15 Answers to SAQs

    i

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    II-

    18.1 INTRODUCTION(&r transportation is the fastest mode of transport today. It has another desirable feature: od record of safety. The second half of the twentieth century witnessed a significant of t h s sector. The planning and designing of airports is a comparatively new s bject, but has made tremendous strides over the relatively sh d period. It is one ofthe e sential functions of a civil engineer. e civil engineering aspects of air transportation cover the location, layout and design irport facilities. These include the runways and taxiways, terminal buildings and r

    ancillaries. Heliports and STOL airports are new subjects that deserve a study.

    a

    I -1

    I

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    Objectives The objectives of this Unit are to cover all civil enginecring aspects of airport planning and design. After studying this unit, you should be able to: have an overview of air transportation as a backdrop to the sub-iect, understand the characteristics of modem aircraft, get an idea of how an airport is located and planned, understand how to develop a layout for an airport, know about how airport pavements are designed, have a knowledge of pla~lni~lg airport terminal buildings, facilities, aids and controls,and understand how Heliports and STOL ports are planned.--

    19.2

    AN OVERVIEW OF AIR TRANSPORTATION --

    19.2.1 T h e Origin of ~ i r ' ~ r a n s ~ o r t a t i o nTo the Wright brothers goes the record of achievement of flying the first powerdriven pline in 1903 at Kitty Hawk, North Carolina in U.S.A. The last 90 year period has witnessed a v e k rapid growth of air transport. The early planes weredriven by propellers. The Dakota, the workhorse of the Second World War, was anextremely popular plane. The propeller driven planes were replaced by turbo-props and later by turbo-jets. The early jets were slim, but the modern jumbo jets are wide bodied to bring in fuel economy. Boeing 747 and Airbus 300 are wide-bodied jets capable of carrying more than 300 passengers. Speeds have also increased; whereas the Dakotas travelled at 258 to 300 knl per hour, modem aircraft can t

    ravel at a speed of about 1000 km per hour. Supersonic aircraft fly at speeds greater than that of sound. For example, Concord travels at 2300 km per hour.

    19.2.2 Role of A i r T r a n s p o r tAir transport has Illany advantages to its credit:

    I)

    Speed: High speed is its greatest advantage. Modern jets can travel at 1000 krnper hour. Advantage of speed is sometimes lost in time taken to reach an airport

    and to reach destination from airport. Speed has caused the world to shrink. Encourages Tourism: International and domestic tourism has grown at a high rate because of air transport. Gives Fillip to Trade and Business: Air transport has gi

    ven a fillip to business and trade. Because of its speed, a good proportion bf high valued goods and perishables are tr

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    9)

    Safety: Contrary to popular belief, air transport is very safe. There are rigidregulations for licensing of pilots and planes and modem technology has provided

    good navigation and control aids. In 1997, about 1330 fatalities took place, the world over. High Cost: Air transport is the costliest mode. In India it is 20times as costly as a bus journey. Noise Pollution: Aircraft generates high level

    of noise. This is particularly true of supersonic jets. The areas near airportsand the path of landing and take off of pla~es suffer from serious noise pollut

    ion. High Energy Consumption: An aircraft may consume per passenger about ten times he1 that is needed for travel in a bus.

    Air Transportant

    rhere are a few disadvantages of air transport: 1) 2)

    3)

    19.2.3 International Air Transport Today[t is estimated that every day, the world's air services fly more than 16 million aircraft tilometres and earn around US $ 400 million of revenue from 3 million

    passenger ourneys and the carriage of 30,000 tonnes of cargo and mail. It provides direct work for nore than 2 million men and women. Air traffic has grown globally at around 5 to 8 2ercent per annum. In many countries airlines are governm

    ent owned but there is now a visible desire to privatise. The privatisation of British airways may be the forerunner to nany more yet to come. India has also taken the route to deregulation and privatisation. Passenger traffic predominates,

    taking a share of 76 percent. rhere are many problems that face the sector today:- he1 shortages, congestion in :ontrolled air space, inadequate airport capacities, noisy aircrafts, replacement of aged iircrafts and low profit margins. Technological changes in the manufacture of aircrafts lave been swift. Llost of the

    countries have three levels of airlines: 1) 2) 3) International. Domestic, trunk route service. Domestic, feeder service.

    19.2.4 Air Transport in India 4ir transport began in India in 1911 when some experimental flights were made by nilitary officers. The same year a French aviator

    flew air mail between Allahabad and Vaini. J.R.D. Tata's solo flight in 1932 fr

    om Karachi to Bombay in a single engined Puss Uoth is now part of history. Indianow has three levels of airlines: 1) 2) 3) Air-India, the international carrierIndian Airlines, the domestic trunk service and Alliance Airlines Vayudoot, thedomestic feeder service

    .n addition there is a Helicopter corporation, Pavan Hans. 411 the above airlines are government owned. There are some private domestic airlines I'he growth ofAir-India and Indian Airlines can be appreciated from figures in Table 19.1. f i

    e average annual rate of growth of international passenger traffic tolfrom India in the lecade 1974-84 was 16 percent. The domestic air traffic during the same

    decade grew at 12 percent per annum. t is expected that international air traffic may grow till the end of the century at 6 percent )er annum. where as domestic air traffic may grow at a higher rate of 11 to 12 percent.

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    \.ir. V ater Transports dt( )~IIPI. ?>stems

    Table 19.1: Growth of Air-India and Indian Airlines

    II II2.

    Revenue Tonne-kin. (million) Indian Airlines Fleet strength

    B

    1.2

    I

    1

    88

    I154

    1 Revenue Tome-kin (million)100.0

    765.2

    I 1

    Major problems facing the airlines today are need for replacement of old aircrafts, congestion at airports, inadequacy of ground infrastructure and shortage oftrained personnel. Terrorism has created new problems of security. Air transport

    is being deregulated world over, and I n h a has also followed suit.i

    19.3 AIRCRAFT CHARACTERISTICS19.3.1 Rapidly Changing TechnologyA civil engineer specialising in transportation has to plan and design facilities for handling aircraft in airports. Aircrafts are of various types and an important feature of the aircraft industry is its rapidly changing technology. In a span of less than 100 years, aircraft designs have undergone dramatic transformations. The craving for speed, the highly competitive conditions under which aircraft manufacturing takes place, the impact of the fuel crisis and the growing concern for preservation of the environment have influenced aircraft characteristics enormously. As a result, the civil engineer has to match his designs and upgrade them constantly. The airports of yesterdays are no longer suitable for aircraft of today and much less for tomorrow. The aircraft planner has to have knowled

    ge of the trends in aircraft de&n in the foreseeable future.

    19.3.2 Aircraft Characteristics that Govern Airport DesignAircraft characteristics, which govern design of airport, can be discussed under

    the following heads: 1) 2) 3) Speed Size and dimensions. Weight, landing gear and tyre pressure

    SpeedThe attraction of air travel is speed. Whereas the Dakota (DC-3) of the 1940s could cruise at around 300 kmh, modern wide bodied jets (Boeing 747, airbus 306 fo

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    r example) can run at 10001an/h. The Concord cruises at 2750 kmlh, much faster than sound. It is doubtful whether such supersonic aircraft will become common in

    future. What is important to an air planner, however, is that having achieved high speeds in the air, the airport and interface facilities must match the highspeeds.

    Size and DimensionThe size and dimensions of aircraft depends upon the number of passengers carried andI ~erange of operations (short, medium, long). A long range 747 jumbo jet can carry up to

    $110passengers. The Airbus A-300, a typical wide-bodied medium range aircraft can carry up to 350 passengers. A 737 Boeing, ideal for short-range operations, has a passenger capacity of around 150 passengers. For very short-range operations, typical

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    lird level carriers, a seat capacity in the range 20 to 50 is common. Passengerity of 800 with a two-deck arrangement is being talked about, but it may take along dimensions of aircraft govern airport planing. Figure 19.1 gives a typicalsketch of ircraft showing the controlling dimensions. k ~ e n g t ---4 hy v g G F i g h t

    Air 'Trunspurtation

    ~ i n $Pg

    Nose Gear

    Landing Gear (Main)

    I

    Maximum Turning Radius Path of Main Gea

    Figure 19.1: Aircraft Dimensions

    mensions of a few common aircrafi types are given in Table 19.2.

    (

    Table 19.2: Principal Dimensions and Characteristics of Aircraftaft e

    1 Sg; 1 IWing Length (m)

    Maximum Weight at Take Off (kg)

    1

    Wheel Track'm)

    Wheel

    7:;

    1

    Height

    Cruising Speed

    04

    850

    weigh4 Landing Gear and Tyre Pressuremum weight of an aircraft is when it is loaded with fuel and is at take-off. Table the maximum weights of some aircraft. of the aircraft is transmitted to the airport pavement by wheels conforming to onfigurations. This is dealt with in section 19.7 ures are h g h In aircraft. Typical values are as under:

    Aircraft TypeBoeing 747 Boeing 737

    Tyre Pressure (M Pa)

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    1.43 1.04

    The man b e s are in the vicinity of 50 x 16 sire. The nose wheels are in the vicinlty of.

    mnr*rr--..

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    for a~rivals is 3500 feet if the tl~resholds of the t\vo runways arc even w ~ th each . If thc thl-csholds are staggered. the separation may he increased or decreased bj. ct f'or each 500 feet staggcr. This is explained in Figure 19.2.

    \if. I

    ~ ~ l t t ~ p ~ ~ ~ ~ t ~ , t ; ~ ~ l l

    Arrival

    ---+ [

    A

    Departure

    -_+Figrrrc 19.2: Srparatiott Between ParaUr.1 Runways

    I 19.4.p

    &;irigatiosal Aidsflight of aircraft is highly depeildent on n~odenl navigational aids. Ver?; higli

    ! :Omni-range equipnient (VOR) is commonly used for facilitating navigation ofstations A VOR receiver is installed in the cockpit of an aircraft. VOR gr0~111d

    aircraft. Their range is about 200 nautical nliles. These stations send out radio all directions. Each signal is referrcd to as a radial. A pilot can select aradial and control the movement of thc aircraft rclative to the selected radialby a Positioil Deviation Indicator (PDI) i~lstalled in the cockpit coiltrol pancl. ons also have Distailcc Measuring Equipment (DME) which gives thc airline etwcen the VOR and the aircraft in nautical miles.toner of ~mportant airports has Airport Surveillnnce Radar (ASR) nhich 360" It glves r~lfonllation of all movenlents wlthin the airspace

    19.5 \AIRPORT PLANNING AND LOCATION

    19.5.1 Types of AirportsTo bcg a few definitions ~vill help in clari@ing the subject of airport planning. 4 with. daj s of a\ lation. the term "aerodrome" was popular An aerodrolllc1IS

    (

    n area including tht: buildings. it~stallations and equipment. intcnded to be art-ival. departure and movemcrlt of aircraft. The term aerodron~c is now rsedcd by the tern] "airport"IT is a facility. consistii~g of civil works. building. installat~ons and equipnient.

    to bc: used for thc arrival. departure and movement of aircnft. A~rl>ortsare oftv o types. viz..1)

    2) \ ~ i l i t a ~airports. -y serving defence needs The Civ' ia11 Airports canbe of three types, viz,.')

    I I I

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    Civil a~rports. serving the scheduled airlines and all phases of gencral aviation

    ir carrier airports, which serve scheduled air carriers. Exanlple: Pala111Airport. bellli. neral ~~vintion airports. \vllich cater to business and csccutivc tlying. air taxi erations. Flying clubs, aerial sowing1medical serviccs. firc fighting. forcst twl ctc. Esampl~: Sufdacjung Airport, Delhi.

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    Air. \\

    .11c1 1 r.~llapurts& 1,tht.r h>slt.ma

    3)

    A mixture of the above two,.cntering to both scheduled air camels c i ~ n i lgcncral aviation. Exanple.. Ludhialla Airport, which allo\

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    pment of airports is but a small part of the overall process of develop~nent ofair transport To extend it further, the development of air transport 1s part ofa country's overall strategy for development transport. trade and touris111 Airport planning has to take ~ t place s 111 thc overall scheme the country has chosen for the development of its economy and ~ t s transport infrastructure and the

    role air transport is assigned to play

    Levels of Airport PlansAirport planning may take place at a various levels:1)

    A long tern1 plan for the development of all airports in a country

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    2)3)

    A long term plan for a new airport being plannedA long term plan for the Improvement of an existing airport.

    ng term plans are comnlonly knowll as Master Plans.

    I ventory of Existing Facilities

    1

    tclear understandillg of the nature and,scale of facilities already available will form the1)

    b sis of assessing the dcficicncies in the system and 'designing for their removal. The ii \/cntory should include details of the following:

    Runways. their number, length, configuration Taxiways Apron Pavenlent thicknessand condition Terminal building and facilities Apronlgate transfer arrangement Passenger facilities Cargo handling facilities Air Traffic Control Aids

    2)

    3)4) 5)6)

    7)

    8) 9)

    10) Airport lighting 11) Scrviccs like electricity, water. sewers and telephones12) Safety provisions 13) Fuelliilg facilities 14) Hangars 15) Traffic handled

    in terms of passengers. cargoes, aeroplane landings and takeoffs, aircraft delays analysis 16) E~~vironmental 17) Airport access faciiities 18) Facilities for p

    arking 111andForecastIC

    key to the fornlulation of a good airport plan lies in nuking a reasonably accurate forecast. The period of forecast should be quite long such that the facility

    does not me congested too soon after it is commissioned. A period of 15 to 20 years after nissio~liilg of the project is almost a minimum for planning purposes. Delnaild forecast based on historical trends. Demand forecast based on econoinetric models ds based on historical trends establish the past growth rate of passengers handled, andled, aircraft landing and take-off. Data for the past 10 to20 years are ed and a regression curve of the following form .is fitted:

    De land forecasts are made by various methods. Some of them are: 1)

    I

    2)

    where.

    T,, = Trafiic in the nthyear7;, = Traffic in the base year, n=O

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    n=r=

    ~lu~llber of years annual rate of growth of traffic, expressed in decimals

    One nlethod is to extrapolate the future design year traffic assuming traffic togrow at the same rate as in the past. If there are reasons to believe that the

    fiiture growth rate 1s likely to be different from the past (based on the judgement of professionals), suitable moderation in growth rate is carried out. Econometric method relates air traffic to various economic and social factors. based of study of past data on these. Ecoliomic and social factors such as GNP, per capita incomc. population urban population, industrial production and so on can beused as the explanatory variables. The models can be of various types. A multiple regression iiiodel can incorporate nlaly variables, and can be of the following form:

    AT = Ao + AlX, +A,&?where,

    + A3X3

    AT

    = Air

    traffic in terms of passengers, passenger-km, tonlies of cargo. tonne-km of cargo etc. Constant

    A.

    = Regression =

    A,, Rz, A3X l , XI, X3Log, AT

    Regression Coefficient variables selected

    = Independent

    The following formula iilcorporates the elasticity of demand:= A.

    + Al log, GNFJ

    In the above equation the coefficient A, gives the elasticity of air trafic (AT)with respect to gross national product (GNP). The elasticity Al directly gives

    the ratio between the percent change in traffic and growth of GNP. Thus for each1 percent growth of C;NP, AT is expected to grow at Al percent. This formulatio

    n becomes convenient, because the planners generally know at what rate the econo

    my and other key variables are likely to grow in future.Gravity models.relating the passenger flows or cargo flows between a pair of twocities to the economic activities in the cities or population of the cities andincorporating ail impedance factor (generally the distance between the cities)

    are commonly employed. Thus. in a simple form,

    AT, =where,

    PIP,

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    4,"ATii = air traffic between i and j Pi, Pi = population of cities i and jdii n.=

    distance between cities i and j constant to be calibrated

    =a

    Technological forecasting can be conveniently applied to air travel demand forecasting, particularly as air transport technology is an area of rapid transformation. High cost of jet fuel and its future availability can influence air travelover the long run.

    19.5.5 Site SelectionThe selection of site for an airport is governed by many factors listed below:

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    Economic Factors I) The area served by the airport must be able to generate andattract the estimated passenger and cargo tiaffic. The airport location is therefore governed by the population of the area it serves, the pattern and the growth of the cities serviced and the location of the industrial centres. play must be clearly recognised. Is the new airport going to function as a satellite to a major airport already existing'? eteorologicnl Factors1)

    Air Transportation

    2 ) The existence of airports nearby and the role the groposed airport is expected to

    Wind velocity, direction, frequency, turbulence and gusts have a major influenceon the airport operations and safety. Crosswiilds are very crucial siilce they

    inay prevent the safe usage of the runway. Runway orientation is so selected that crosswind components are minimal. A study of wind duration, speed and direction over a period of years helps to determine the best orientation of the runway.The altitude above mean sea level influences runway length. Other things being equal, a longer runway is required at higher altitudes. Roughly, the runway length needs to be increased by about 7% for every 300-m altitude. Average temperature of the hottest month also influences the runway length. The higher the temperature the longer the runway. Visibility conditions, particularly frequency of low

    visibility conditions due to fog, mist, rain, smoke, low clouds, dust storms et

    c., can affect aircraft landings and take-off significantly. These conditions must be studied in advance and unfavourable sites must be eliminated. Icing record.

    2)

    3)4)

    5)

    hysical and Engineering Factors 1) The site.selected should have a fairly levelarea with gentle contours. This will minimise the cost of earthwork for levellin

    g and keep the runway length to the minimum. Every 1% increase in the average longitudinal slope of the country causes 10% increase in the runway length. 2) Thesite selected should permit easy acquisition of land needed for the runway, apr

    on and terminal. For a small airport, 20 to 40 hectares of land may be adequate.But large airports consume as much as 6,000 to 15,000 hectares. Site should per

    mit fbture expansion if need arises. The prksence of built up properties, industrial establishments, hills, rivers, harbours, etc., hinders future expansion. It

    is always prudent to anticipate the future land needs and acquire it at the initial stage. If this is not pbssible due to resource constraint, the future landneeds must be identified and land should be protected from uncontrolled growth by zoning laws. An elevated site is ideal from many considerations: it is usually

    free from obstructions in the approach zone, it is easy to drain and often it is less prone to fog and adverse wind conditions. Soil conditions must be favoura

    ble. A good subgrade soil with high supporting strength can reduce the airfieldpavement thickness considerably. A drainable soil enhances the performance of pavements. Frost susceptibility must be evaluated and guarded against. A good site

    is one, which has natural drainage. Floodability of the area must be carehlly studied and the site should be free from it. A high water table can reduce subgrade's bearing power.

    3)

    4)

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    5)

    i

    1 i

    6)

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    7)

    Airport approaches must be clear of all obstructions. In particular, the plannershould look for hills, tall buildings, towers, chimneys, and transmission lincsand avoid them. Thc location of a new airport must not hinder the traffic flow

    in the airports nearby. There should be enough airspace available for the safe landing and takeoff of aircraft in the new facility, without interfering with the

    operations in the nearby existing facilities. The site should be easily accessible form the nearby residential. industrial and commercial areas. A good systemshould be available so that time loss is avoided. Otherwise the very advantage of airport is lost.

    8)

    9)

    10) The location of towns and villages nearby should be studied, particularly with reference to any adverse impact due to noise. The maximum noisc level is generally set at 85 dBA in a daytime and 75 dBA at night for populated loCalities nearby. 11) Thc site should have essential services like electricity, gas, water,sewerage, and telephone. 12) Construction materials, particularly stone aggregates should be available at eco~~omical leads. 13) The site should be free from features that attract birds. which cause bird hits. In particular, slaughterhouses

    and refuse dumps should not be present near the proposed airport location.

    19.5.6 Airport Size and CapacityThe efficiency of an airport is measured in terms of minimisation of delay in landings, take-off, and handling of passengers and cargo at the terminal. The airport size and capacity are deterinined with this objective in mind. The term "capacity" can be defined by various ways but one common definition is that the capacity is the number of aircraft operations during a specified interval of time corresponding to a tolerable level of delay. Various factors affect the cap'acityof airports. Somc of them are:1)

    The number of runways and whether they are used for both arrivals and take-off or separately for arrivals and takeoffs. Orientation and configuration of runways

    . The taxiway Apron layout Weather conditions The mix of aircraft using airportThe efficiency of navigational aids The efficiency of traffic control facilitiesPassenger and cargo handling systems

    2) 3)4)

    5)6)

    7)8)9)

    A single runway, used both for arrival and departure, can have an annual capacity of 170.000 to 2 15,000 aircraft operations. This m g e corresponds roughly 40to I00 operations per hour, depending upon aircraft mix and flight rules (instrumented or visual).

    19.5.7 Airport Construction CostCosting of an airport project includes the following iterils:

    A) Construction Cost 1)

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    Planning

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    .Air, Water 'l'ransports & Other Syste~ns

    c) Aproi~ terminal interface (passenger bus. aerobridge. mobile lounge. stairs)d) Cargo handling e) Vehiclesf) Air Traffic Controls'

    g) Fire fighting h) Fuelling

    19.5.8 Financial AnalysisThe financial analysis of a11 airport takes into account the expenses incurred on construction. operation and maintenance of the airport and the revenue derived.Cost Head Revenue Items

    Constructio~l cost Interest on borrowed capital Maintenance of buildings, pavements, utilities, equipments, furniture etc Cost of security amngeineilt Cost of personnel COGof fire services

    Rental income frotn office area leased to Airlines, Posts and Telegraph department Rent from concessions granted to restaurants, bookstalls, duty free shops etc. Lease of car-parking lots

    Lease of space for aircraft parking

    . ! +Rates and fees from aircraft landing Fuel service fees

    19.5.9 Economic AnalysisThe benefit from airport project includes the following:5)6)

    Reduction in delay Savings in fuel consumption Savings in time Increased economic activity k s e in employment

    7)

    8) 9)10) Increased land value

    The cost includes the cost of construction and maintenance of the airport over aperiod of time. All costs and benefits are "economic" cost, net of taxes and su

    bsidies.

    19.5.10 Enviranmental ImpactAirports adversely affect the environmental quality of the area around. This 1sparticularly tnre of noise. Other pollution effects are air and water. The airport may destroy areas of scenic beauty or natural landscape. It can cause displacen~ent of people. All these effects must be studied and included in the Environm

    ental Impact Assessment Statement that should accompany a Project Report.

    SAQ 1a) b) c)d)

    What are the speeds of modern aircraft? What is the role of air transport in themodern \vorld4? What are the disadvantages of air transport? What are the threelevels ofairlines in countries'?

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    1i

    11

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    e)f)

    What are the government airlines in India? What are some of the problems facingair transport today?

    Air Transportatior~

    g) What are the principal dimensions and characteristics of modern aircraft? What is the tyre pressure on some of the modern aircraft? Why is it necessary to have a good air traffic control systems in an airport? What is VFR? What is IFR? How is the flight route of an aircraft controlled'? What are the aircraft route separation rules? What are the criteria for separation of runways? What is a VORstation? What is PDI? What is ASR? What are the common types of Airports? What is STOL? What is VTOL? What is CTOL'? What is RTOL? are the steps of Airport Planning? w) Wl~at x) y)I

    What is the information to be collected in an inventory of existing facilities?Demand Forecast made for an Airport'? How is Traff~c

    z ) What is a Gravity Model? aa) What considerations govern the selection of site for an airport? bb) What factors influence airport capacity? cc) What are theelements of the cost of , a n Airport pro-ject? dd) What are the cost and revenu

    e stream in a Financial Analysis of an Airport Project? ee) How is the EconomicAnalysis of an Airport Project camed out? ff) How is Environmental Impact important in an Airport Project?

    19.81 AIRPORT LAYOUT19.6 1 Airport Layout ComponentsThe ain components of an airport layout are:)

    tI

    Airfield, consisting of the following: a) Landing strip, consisting of a runway,shoulders and stop-ways. b) Taxiways

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    Air, Water Transports & Other Sy5tetns

    c) Apron 2) Terminal area, consisting of the following: d) Gates e) Terminal building

    f) Aircraft service facilities3)Flight support area, consisting of structures and facilities for air traffic control, navigational aids, fbelling the aircraft etc.

    The runway is a strip provided specifically for landing and take-off. It is generally paved. Shoulders are provided on either side of a runway t o serve as safety zones should an aircraft go off the runway sideways during landing or take-off. They are generally unpaved. Stop-ways are provided at the ends of a runway, again for safety. to accommodate an aircraft that overshoots or undershoots a runway dur~ng landing or has an aborted take-off.

    A taxiway is a strip (usually paved) connecting runway with one another and withthe aircraft-parking apron.

    The apron is the hard-standing area where aircraft are parked. Passengers enplane 1 deplane here and cargo is loadedlunloaded here. Fuelling and other servicing

    is also carried out here.

    A holding apron (also called a run-up area) is that portion provided near the en

    ds of a runway for engine run-up and for hitching or unhitching vehicles towingthe aircraft. They also serve as area for aircraft waiting for take-off.The gate is the opening in the terminal building through which passengers enterlleave the terminal building on arrivalldeparture from an aircraft parked in theapron. The transfer of passengers from the gate to the aircraft is accomplishedby various svstems.y -

    .'.

    . .I-

    Arrival / Departure Airspace''.,

    .'.'.' .'

    .-

    Figure 19.3: Typical Layout oTAirport

    The terminal building is designed for handling ofpassengers, cargo and airmail from ground to air. Hangars are buildings where aircraft are serviced. Flight sup

    port area consists of a number of structures and facilities for air traffic contro, navigational aids and fbelling the aircraft.

    19.6.2 Obstruction CriteriaLanding and take-off of aircraft requires that the zones at either ends of the runway be clear of obstructions. In order to achieve this the dimensions and shapes of obstacle surfaces have been standardised. ICAO recommendaticns for approach runways and take-off runways are given in Tables 19.3 and 19.4 respectively.

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    Table 19.3: ICAO Standards for Approach Runways

    Air

    Trs~~spvrc.tri,~t~

    Visual Runways

    Instrumentation

    Isurface is one which is longitudinally centred on a runway and which beyond each

    end of t l ~ e nmway. rizontal surface is one which is a horizolltal plane 45 mabove the established elevation and is a circle whose centre is at the airport

    reference point (geographic f the airport) and whose radius varies froin 2000 to4000 m.

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    .\ir,

    \\ nter' Tla~lspur't\8r

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    ed that the crosswind components are minimised. A comnlon guideline is that a !land at least 95% of the time with cross wind components not exceeding 25 per hour, which is considered to be the safe limit for light and inediuin weighi is limit is not relevant for modem heavy jets. To meet the above-mentioned ts. the orientation is decided on the basis of past data on the occurrence of entation should be parallel.to the city border so that flights do not occur over reas causing noise nuisance.

    Air Tra~~sportntion

    nway Dimensionsthat influence runway lengtll are: 1) Type of the aircraft, its take-off and landing characteristics Elel~ation of the airport Gradient of the runway Pn\~ementconditions Tempcrat~ires of the arca e critical conditions are examined based on

    aircraft characteristics:I)

    2)3)

    4)5)

    Thc runway length should be sufficient for the aircraft to accelerate to the poi

    nt of take-off and then in case of failure of the critical engilies the aircraftbe braked and brought to a stop within the lin~its of the runway or useable landing strip (aborted t'ake-oft).Jf the fail~~re of critical engine occurs at a point of take-off. the aircraft should be c:lpablc of take-off on the operating engine (or engines). The aircraft

    powered b \ reciprocating engines must be able to clear the runway by 15 n1 andthose powered by turbine engines at an elevation of 11 in. In Innding: the airc

    raft should clear the end of the nlnway by 15 n1 and be landed and brought to halt within 60% of the available runway length. The latter provision ensures thateven if the aircraft lands at a speed exceeding the design value, there'is suficient length to take care of the landing. p of the above criteria, it is theoretically possible to calculate the ninway knowing the take-off and landing-characteristicsof the aircraft. Another chis to use experinlental data on aircraft perfo

    rmance during landing and take-off dardised by various authorities. American practice (Federal marised in Table 19.5. Typical nmway lengths of different 10.7 summarises another feature of runway such as width. gradient ctc. as per ay showing typical features is given in Figure 19.6. way affects the performance of the aircraft. &sing r take-off, and downward gradients need more braking ed for com~nercial use, a maximum gradient of 1.5% is ients can be slightly increased to 2%.

    be avoided. When they are unavoidable. they should ical curves. The minimum length of the vertical curve r carrier airports and 90 m for utility airports.

    )

    )

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    i;..

    \\

    atcr Transp

    IIIL,I. Systems

    Shoulder

    Paved Runway

    Shoulder

    Figure 19.6: Runway I 'ross-srctio~~

    Table 19.5: FAA Standards for Physical Characteristics of Airpot.ts (Dimensionsin feet)

    Runway Length Runway Width Landing Strip Width Taxiway WidtliMinimum Distance Between

    -Centre lines of parallel niliways -Centre lines of runway and Centre lines of tasiway -Centre line of nlllway and aircraft parking area -Centre line of tasiway

    and aircratl parking apron -Centre lines of parallel taxiways -Centre line of runway to building lines or obstn~ctiolls -Centre line of tasiway to obstn~ctionsEffective Loligitliciillal Transverse

    300150

    300

    150

    200

    20050

    50

    100

    100

    200

    200

    50

    50

    Marimun runway grades, "/o

    I1 if I11 .O

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    :::1.5

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    Typical Runway Lengths for Various Types of AircraftNormal Mar Temp. of Hottest Month ("F)

    100

    Sea Level

    10,500

    Table 19.7: ICAO Standards for RunwaysICAO Airport Code Designation

    1

    between centre

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    Air, Water Transports & Other Systems

    19.6.6 TaxiwaysSince aircraft travels at a much-reduced speed on taxiways. their dimensional requirements are lower than for runways. ICAO standards for &xiway dimensions aregiven in Table 1.9.8. Table 19.8: Taxiway Dimensions and DetailsItems ICAO Airport Designation

    Width of taxiway (m) Maximum transverse gradient of taxiway (m) Maximum longitudinal gradient of taxiway (m) Width of taxiway margins (m) Width of taxiway strip

    (taxiway + n p a v e d paved or u 1.5 1.5 10.544

    1.5 1.5 10.544

    1.53

    2 3

    23

    7.5 30 25 22The exit taxiway from a runway can be either right angled or at some other angle. An angle of about 30" permits aircraft to clear the runway quickly at speeds of the order of 100 km per hour. Such exit taxiways can be conveniently located at about 800 m, 1200 m, 1800 m, and 2000 m from the runway threshold such that avariety of aircraft can be served. Taxiways exit details are given in Figures 19.7 and 19.8.

    ----

    - -

    _ _

    -

    C

    , Runway - ,i _

    . . ---. ...J, - .'..\- - - - - - - - - - -.- - -- Taxiway

    . . C

    Figure 19.7: Taxiway Exit Details

    1400-170Om Light Turbojet Narrow Body

    550-800m Small Propeller Aircraft

    t

    2000-2200m Heavy Widebodied Jets

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    e'

    Figure 19.8: Taxiway Exit Details for Various Types of ALrcnft

    19.6.7 ClearancesFor safety of operations during taxiing, separation clearance is needed. Table 19.9 gives the clearances for various airport designations.

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    Air

    Table 19.9: Separation ClearancesICAO Airport Designation

    Item-

    precision instrument runway lion-precision instrument runway

    19.6.b

    Holding Apron

    y airports, aircraftshave to line up for take-off. Storage areas are provided for aircraft and these are called holding aprons (or run-up pads or holding bays)

    19.6.1 Apron

    is the area adjacent to the terminal building intended for loading and aeroplanes. The number of spaces intended for aeroplanes depend upon the ircraft expected

    to use the apron at one time and the time of occupancy. The upancy is more at terminal airports than for en-route stops. The time required and unloading varies

    from 20 to 45 minutes, depending upon the aircraft size g equipments. The gradi

    ent of the apron should be adequate to drain the off but not in excess of 1.0 per cent.19.6. 0 Hangar

    t ar is a covered area intended for the purpose of repair and servicing of aircraft.e of hangars depends upon the dimensions of the aircraft they serve.-

    19.7 # AIRPORT PAVEMENT

    19.7.1 Requirements of Airport Pavement

    Airpo pavements must meet the following requirements:1)2)

    1They must have adequate strength to withstand the heavy loads imposed bymodern aircrafts. They must take care of the repetition of loads over the design

    life of the pavement. Because of the high speeds at which aircrafts land and take-off, the pavement must take care of the interaction of vehicle response and pavement surface. For this purpose, the surface should be sufficiently smooth.

    3)

    4)1 The surface should be anti-skid.5)1 The pavement should be dust free and take care of jet blast.

    611 The inaintenance needs of the pavement should be minimal.7)

    831 The cost of the pavement should be economical..These re hiscussed in detail.

    I

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    The pavement should withstand the detrimental effect caused by fuel and oil spillage.

    I

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    Air, Water Transports & Other Systems

    Ability to Withstand Heavy Loads of Aircraft and High Tyre Pressure Modern aircrafts are giant in size and are very heavy. The present generation of a~rcrafts have a weight of 350 tonnes. The Boeing 747, for example, has a take-off weight of 35 1.1tonnes. A weight of 500 toniles may be well within the realms of possibility in the foreseeable future. In contrast a heavily loaded truck trailer combination has a weight of 50 tonnes. Such heavy loads are transmitted by landing gear tyres to the pavement. The landing gear assembly consists of a number of tyres arranged in various configurations. Some are shown in Figure 19.9. The B-747 has 16 tyres in the landing gear and tw7o in the nose gear.Landing Wheel-

    < N O "

    Wheel

    0

    0 0 0

    Twin Tandem Landing Gear

    co

    0 0 0 0 0 00 0-*-

    Double Twin Tandem Landing Gear (Boeing 747)Figure 19.9: Landing Gear Configurations

    -

    00

    00 0

    High tyre pressures are associated with modern aircraft. The B-747 landing geartyre pressure is 1.43 MPa. In comparison, a heavily loaded truck has a tyre pressure of only 0.8 MPa. Take-off weight is higher than the touchdown weight because of the fuel stored at the Qke-off. Thus, repetitions of take-off are more severe than touchdown. Ability to Withstand Load Repetitions Though there is a designated area for touchdown of aircraft in the runway (around 300 to . 400 m from the threshold), there is a lot of variation in the landing position both transversely and longitudinally. Bascd on observed distribution of touchdowns, it has been roughly computed that for B-747 aircraft, the probability of a load occurring

    at the same location is 0.0038 per landing. This implies that one load repetition takes place per 265 landings. Compare this with highway loading where it is assumed that every vehicle contributes to one repetition. For a busy highway. 50million repetitions of standard load of 8.16 tonnes are quite often met with. But for runway pavements, with around 200,000 landings m d take-off per year (a normal figure for a very busy airport runway), the load repetitions at the touchdown condition is only 400 per year. For design life of 20 years, the coverage with touchdown.impact works out to only 8000. The number of repetitions of loads on

    taxiways and other portions of runways, (away from the touchdown zone) would, of course, be higher. These can be calculated from the' aircraft wander, which is

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    the lateral shift in movement of aircraft. The effect of aircraft wander is toreduce the number of load repetitions. The actual reduction depends upon the type of the aircraft. Aircraft - Pavement Interaction Modern a~rcraft travel at high speeds on the runways. Speeds between 150 and 250 km/h are common at take-offand touchdown. On taxiways, speeds are in the range of 60 to 100 k d . The surface evenness of the pavement becomes extremely important at such speeds. Vibrations are set up in the aircraft travelling at high speeds on rough surfaces Thesevibrations not only cause discomfort to passengers, but also affect the pilot's

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    o control the aircraft. Thus the safety of operation is also involved. Modern avements are, therefore, designed and constructed to give a smooth surface, its the dynamic response at the interface of landing gear and pavement. The h of surface roughness becomes a significant factor of design. This is often by specifications laying down the permissible irregularity in surface when y a straight edge.

    ~ k i d e e s i s t a n Surface t surfBce becomes sntooth and wet, the frictional resistance offered at the tyre nt interface comes down significantly. If there is a film of water at the surface, of an aircraft travelling at htgh speeds may entirely lose its contact with road , creating a hazardous condition known ashydroplaning (ar aquaplaning). The loses its steerability and may go off the'runway. It may also over-shoot the Pavements are therefore made with a good texture

    and a proper cross slope for r to quickly run off. When pavements lose their texture, they can be grooved. provides quick outlets to water. of Jet Blast rtantconsideration in airport pavements is the need to allow for the effect of jet engines can be easily damaged by particles sucked into the air intake. ~ 6 i s necessary for the pavement to be dust free and free from particles that may be

    Effe

    +

    ~ e a s Maintenance ( Option nts deteriorate due to traffic and require maintenance. Maintenance operations c dislocations, which can be very severe in airports

    and cannot be tolerated. rence is given to'those designs that result in pavemen

    ts needing the least e. Runway and taxiway pavements are critical in this regardwhereas apron an tolerate some dislocation caused by maintenance. el and Oil Spillage f fuel and oil fall on the pavement from the aircraft. These can dissolve

    the surface and cause its early disintegration. This is especially true of bituminous ecause bitumen gets dissolved in petroleum products. Cement concrete ~con(mica1 Cost

    st of an airport pavement is high. Economy can be achieved by selecting the riate materials which are locally available and which have the requisite strength.so be achieved by designing airport pavements considering the variation porti'ons of runways and taxiways experience different loading. Loading is very a fullyloaded plane takes bff or touches down. During engine run up at the ,full static

    load plus stresses induced by vibrations become critical ements. Slow moving tr

    affic on the taxiway also results in high stresses. The channelisation is severefor taxiway and runway ends. s economical to design pavements at different sections of runways and taxiways of expected load coverage. on to find the end 10 per cent of the runway provided with a thicker section. central portion is often made thicker to account for channelisation effect

    19.7. Comparison with Highway Pavement

    t ce, a highway pavement and an airport pavement are similar to each other. Bothoads from rubber tyred vehicles trAvelling at htgh speeds. Both are built-up ofconcrete, stone aggregates and bitumen-bound layers. Both rest

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    4ir. \Vater Transports & Otlier Systems

    Pavement Thickness

    .

    -

    Width of Runway

    >

    I

    -

    Figure 19.10: Thickened Portions of Hunwny Pa\enynt

    There are some differences between airport and highway pavements. Firstly, Airport loading are very high when compared to highway loading. Tyre pressures of aircraft are also higher than highway tyre pressures. The impact of aircraft on landing is very high. For ensuring smooth flow at very high speeds, runways surfaces need to be built to a very high degree of finish, free from bumps. Skidding be

    comes a serious problem at the very high speeds of the aircraft and extra care has to be exercised to prevent hydroplaning.

    19.7.3 Types of PavementAirport pavements are of two types: 1) Flexible pavements Rigid pavements

    2)

    A flexible pavement is made up of one or more layers of materials, the highest quality' material is positioned on top. Loads are transmitted through the layers.

    The material forming each layer and the thickness of each layer are so chosen that the stresses in each layer are within the permissible value. The total thickness provided ensures that the stress on the sub-grade is within its bearing pow

    er. The load carrying capacity of the flexible pavement is derived from the loaddistribution property and not from its flexural or bending strength. Because ofits poor flexural strength, the pavement depends upon the load bearing propertyof the subgrade soil to a substantial degree. A rigid pavement (constructed wit

    h cement concrete) depends upon the flexural strength or beam action of the slabfor supporting the wheel load. Thus, a major contributor to the load bearing ca

    pacity is the slab itself. Slab strength plays an important role, the subgrade support contributing a relatively small part. The slab can in fact bridge acrossweak spots or minor variations in soil sub-grades. A flexible pavement, having bituminous wearing surfaces, is very smooth and is highly suitable for the high l

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    rer loa

    is to be allowed because of the fatigue behaviour of materials under repeated

    Air Transportation

    Bituminous Wearing Surface Bituminous Base Lower Base. Course Concrete Slab

    Sub Base Subgrade

    Sub Base

    Subgrade

    I

    Figure 19.11: Pavement C:ourses

    In e early days, when the aircraft loads were small, the design of aiqort pavements was an extension of the principles of highway pavement design. In fact, thewidely see knl n Corps of Engineering method of airport pavement design is derived from the which were originally developed for highway pavements. But as the complexities CUI of rcrafi grew, and particularly as speeds and loads increased, the design methodology ha! ndergone a process of constant evolution. It cannot be

    said, though, that a perfectly ry method has now emerged. The search is still on. sat Es; s ntially, the design methodologies can be broadly grouped under:

    tI

    I)

    Empirical methods Analytical methods

    12)

    En irical methods are based on a study of observed performance of airfield pavements 0v1 a period and are purely based on experience. Typical of this group is t

    he Corps of method based on CBR values. EnAn1 lytical methods utilise the stress strain behaviour of pavements under loads

    and have at' oretical basis. Westerguard's analysis of stresses in a rigid pavement and Bu inster's layer theory are typical examples.

    T h advent of computers has rendered the use of analytical methods easier.19.!.6 Design of Flexible Airport Pavement U. Corps of Engineers Method Th ineers,hho, were involved in the construction of many military

    te(

    4.

    a.ir str gi~

    rld War 11, has developed their own design methodology. The soil n terms of CBRvalues. The early curves developed by them are

    ArI lysing &e performance of various airfield pavements, the following mathematical ex1p ession was evolved:

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    t

    where,t = pavement thickness, in inches

    P = Single wheel load, in lb.

    A

    = Tyre

    contact area, in sq.fet.

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    t h s procedure: Corps of Engineers have developed design curves for typical ercial aircraft. The curves are given in Figure 19.14.

    Air Transportalion

    Subgrade Strength, CBR

    .

    ,

    Figure 19.14: Corps of Engineers Thickness Design Chart for Selected Aircraft

    ,-.

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    .\ir, \\'atrr Tranbports & Otl~rr Systems

    percent to take care of curling stresses, load repetitions and other cont~ngencies. The ncl load (= 0.75P x 1.33 = 0.98P) is used for designs.

    Federal dviation Agency MethodThe typical FAA rigid pavement design chart is given in Figurel9.16.

    The chart gi 1) 2) Aircraft weight Annual departures Modulus of Subgrade Reaction Concrete Flexural strength

    3)

    4)

    General Features of Airport Rigid PavementsTransverse contractio~l jolnts are provided at longer spacing than in highways Typical range is 4 to 8 m Transverse expansion joints are not generally used except at intersections Dowels are used where load transfer occurs. A sub-base is general11 provided to givc a firm support. Reinforcement is desirable for controlling cracks.

    19.7.8 LCN Method of DesignsTile Load Classification Number (LCN) is a method of aircraft evaluation and pav

    einelit design first used by the Air mil list^. 1JK Vie method espresses the supporting capacity

    coatrct~in2=ESWL/TyIC~I.igure 19.17: L( 'N C'urve

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    Air Transportation

    area of the aircraft in use when the LCN method was devised. a smooth curve awl1(Figure 19.1.7).

    \

    W,, W2 = failure loads, lbA,, Az= load areas, sq. in.

    he curve that was developed is given in Figure 19.18.

    Figure 19.18: Failure Load I Contact Area Relationship

    EquivalentSingle Whal Load, loo0 Ib. Figure 19.19: LC.3, Load, l y r e Fressurc,tYortact .\re*~elati;nshipv

    fnr

    GI-n'hlp and

    Ridd Pavements

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    Air, Water ~ r a n s ~ o & ks Other Systems

    The LCN curve and failure load curve were then combined to produce a chart glvenin Figure 19.19 using the following procedure: 1) The tyre contact area lines w

    ere drawn from th; relationship

    2)3)

    load Contact Area = Tyre . pres.suruOne point on each LVN line comes directly from the standard load classificationcurve. Other points were calculated using the equation given above. Dotted lines

    are tentative extension of the LCN system to accommodate contact areas less than 20 sq. m.

    4)5)

    ACN-PCN SystemThe ~ C A 0 ' h adevelopcd s an airport pavement classification system for reporting pavemcnt strength. The system. known as ACN-PCN, reports a pavemcnt classification 'number (PCN) which indicates that an aircraft with an aircraft classification number (CAN) equal to or less than the PCN can operate on the pavement subject to any limitations on the tyre pressure. A given aircraft will have a diff

    erent CAN dependent upon the pavement on which it operates, whether flcxible (F)or rigid (R) and the subgrade strength. lCAO permits some overloading of the,pavement by aircraft with ACNs slightly larger .than the reportcd PCN.

    19.7.9 OverlaysWhen an existing pavement deteriorates structurally and fi~nctionally, an overlay is provided. Overlay can be rigid overlays or flexible overlays. The following

    equation is recommended by US Corps of Engineers for a-flexibleoverlay on a rigid pavement:t = 2.5(Fhd -Chh)

    where,t

    = overlay(flexible ) thickness, (inches)

    hd = thickness of cyment concrete pavement assuming that the existing pavement did'not exist, (inches)h = thickness of existing pavement, (inches)

    F = a factor having values in the range of 0.6 to 1 .O, which can be determinedfrom a chart if the Modulus of Subgrade Reaction and the number of annual departures are known.

    Cb= a condition factor for existing pavement, having values in the rangelof0.75

    to 1.0.The following formuliis-rec.ommended by Corps of Engineers and Federal AviationAgency for determining the thicknessof concrete overlays:

    where,

    h, = thickness of overlay (inches) h, = thickness of existing slab (inches)

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    subgrade with a working stress equal to that of the overlay slab, (inches)C = a coefficient having the following values :C = 1.0, if the existing pavement is good C = 0.75, if the slab has initial comer cracks, but no progressive

    cracks

    ( I = 0.35, if the slab is badly crackedU!re of Geo-synthetics

    use of geo-synthetics is becoming popular in bituminous overlays. Geo-syntheticsbe in the form of geo-fabrics or geo-grids. The introduction of a mat of these

    helps to ent reflective cracks appearing on the overlay and to add additional strength.

    a) What are the components of an Airport? b) Define the following: Airfield Terminal area Flight support area Runway Taxiway Apron Holding apron Gate Terminal building Hangars c) d) e)f)

    What are the various obstruction criteria for airport? What are the common configurations possible for runways? How is the runway orientation decided? 'What are

    the factors that govem the dimensions of a runway? Give the runway length and width required by Boeing 747 aircraft? What are the standard dimensions of a runw

    ay? Give a dimensioned sketch of a runway cross-section. Give typical dimensionsof a taxiway. Give sketches of taxiway exit details.

    g) h) i) j) k)

    1

    1) What are the clearance required for runways and taxiways? m) What are holdingaprons? n) What is an apron? o) What is a hangar?

    I

    p) What are the requirement that must be fulfilled by an airfield pavement? q) What are the common values of tyre pressure met with in airfield pavements?

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    a

    What are the qualities in a pavement surface that are needed for an airficld pavement? Why is jet blast an ilnportant consideration in airficld pavement design'? Why is the effect of fuel and oil spillage an i~nportant consideration in aircraft pavements'? Give a cross-section of a nln\vay pavement. Compare an airficld

    pavement and a highway pavement. What are the features that distinguish a flexible pavement fro111a rigid pavement? Give a sketch of the co'urses in an airfield pavement of the tlexible and rigid type. What are the empirical and analytical

    methods of pavement design? Describe the US Corps of Engineers method of dcsignof flexible airfield pavement. Describe the Federal Aviation Administration met

    hod of design of flexible airfield pavement. Describe the US corps of Engineersmethod of rigid pavement design for airfields Describe the Federal Aviation Agency method of rigid pavement dcsign for airfields. What is LCN'? Give the formulae for rigid and flexible overlays over a rigid airfield pavement. How are geo-synthetics used in overlays for airfield pavements'?

    1 9 3 PASSENGER TERMINAL BUILDING19.8.1 FunctionThe passenger terminal building 1s the hub of activities in an airport. It actsas the interface between the passenger and the aircraft. It receives the passengers from the city who are outward bound, processes them and their baggage and transfers them to the outgoing aircraft. S~milarly, it rec,eives the inward boundpassengers from the incoming aircraft, processes their baggage and enables them

    to continue their journey to the city. It p r o v u h various types of fac~lit~es for passengers.

    19.8.2 Design RequirementsThe desigh requirement of the passenger terminal building are given below :Passenger Re(luirements1)

    The functional areas should be adequate to handle the passengers and visitors within minimum time. The terminal bullding should take care of the comfurt and convenience of passengers Adcquatc protection should be given to the passengers from exposure to weather blast. noise, h m e s and ground service vehicles. All Iarqe

    2)

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    and illedium sized airports now provide covered loading bridges facilitating direct passenger emplaning and deplaning and weather protection.3)4)i)

    There should be adequate curb space for all automotive vehicles for emplaning and arriving passengers, together with parking for rental cars and taxi queues.'1

    Adequate and convenient parking should be provided for motor vehicles close to thc terminal building. The arrival and departure zones should be separated so asto avoid conflict. A simple, clear and concise sign system should be provided to

    direct both autolnotive and pedestrian movements around the vicinity ,of the terminal areas. A good and easily understandable flight information system shouldbe installed, providing information about airline arrivals and departures and this should be capable of periodic updating.

    6)7)

    8)

    A \yell designed public address system should be provided for informationalThe tern~inal building design should permit direct passenger flow routes, avoiding confusion and involving mininluin changes in levels and direction.

    9)

    10) The terminal should provide for secure, rapid and efficient handling of baggage. Flow of baggage should not conflict with flow of passengers.11) For the convenience of passengers, there should be facilities like toilets,

    restaurants, bookstalls. shops, retiring rooms, telephone, postal services, bankAirlines Requirements 1) There may be one or more airlines operating their serv

    ices. Each of them must have adequate space for ticketing, passenger check-ins a

    nd functional areas for their staff.2)3)

    There should be adequate security arrangements. Functional areas should be set apart for security staff. The facilities must be compatible with the aircraft using the airport. e expansion, both vertically and

    Airport Management Requirements

    2)3)

    The space must permit locating adequate number of concessionaires who cater to the various needs of the passengers who are a source of revenue. The mechanical equipment that handles the passengers and cargo should be sturdy and easily maintainable.

    Com~nunity Requirements1)

    ~ j l ternlinal e must be close to the community it serves and be easily accessible. There should be a good surface transportation. The environmental impact sho

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    uld be minimum. The terminal should be functional in design ar;ld not an architectural monument.

    2)3)

    4)

    19.8.3 Components of a Terminal Building Thc three main components of a terminalbuilding are:

    1)2)3)

    Passenger access interface The processing system The flight interface.

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    The passenger access consists of the roads, curbs and parking facilities. Thc processing system consists of airline ticketing and check-in facilities. flight information. passenger arrangements, security area. customs area, imlnigration area and airport nlanagenicnt staff area. The flight interface consists of the departure lounge arid gate-al~ronintcrhcc. Passenger Access Interface ah l o ~ ~be l

    d eastly approachable by roads havl~lg adcquate capnc~t?'The curb The t e r ~ n~ ns length should be adequate for loading and unloading of passengers There sl

    lould be road space for queuing taxies and a~rport buses The parking may be surface pnrkln!: or 111111t1storey parking. The space between the curb and terminalb u ~ l d ~ n should g be I\ lde cnough and covered to protect from elements Passenger Processing Systemarc As so011 as the passenger enters the terminal building, he enters a foycr. around ivl~ich located various airline offices. check-in countcrs and facilities.

    counter. check-~n countcr and The airlines functional areas are occupied by theticket~ng the baggage coilve)ra~ce system Additional space is needed for the airlunes staff The check-m counter should permit space for the expected queues.Thc h y e r contai~ls adequate scat~ng space for passengers and enough clrculatlon areas

    Passengers nced various types of fncilit~es herc such asI)

    Toilets Restaurant and snack bars Shops Book stalls Telephone facilities Postal

    facilities Bank Information on hotels3)

    4) 5)6)

    7)8)

    9)

    The entrance foyer and departure foyers are generally separated to avoid conflic

    t m movement. Restaurants can be located in the upper floor. Retiring rooms forshort-term stay of bonafide passengers can also be provided on the uppcr floor.Security arrangements are now an unavoidable feature of passenger processing. X-ray devices for baggage checking are common. Adequatc space is nelded for the security personnel. Customs and immigration checks are needed for international flights both at the embarkation end and at the arrival end. Incotn~ng baggage is conveniently handled through conveyor system For arr~vnls. baggage handling IS done through conveyors. Sufflcicnt movement space IS needed around baggage claim area for manoeuvring the luggage trolleys.

    The Flight InterfaceFor departing passengers, the flight interface consists of a departure lounge. an emplan~ng gate and an aircraft boarding system. For miving passengers. the sam

    c system works, but there is no need for a lou~i~ge. Passenger lounges must haveadequate seating capacity. 80 to 90 percent of tlic aircraft seatlng capacity is a reasonable estimate of passenger lounge seating requirement. Duty-free shops

    are provided for international passengers near the passenger lounge.

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    ~411. Transportation

    1)

    lnteniatiorial traffic Domestic arrival Domestic departure

    2)3)

    departures! separate buildings may be earnlarked for different Airlines. (Example: rate building for-departureof Indian Airlines and Private Airlines in De'lhiairport for

    11 airports the terminal building houses almost all the activities connected with an . These include passenger processing, aero~lautical engii~eering services,control

    Passenger Lodmg Bridge

    b w e r Road Level

    Figure 19.20: Three C!oncepts o f Levels for Terminal ~ u i l k i n Design ~

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    1

    Air., Water. 'Trailsports & Other Systems

    4) The passengers ark conveyed in mobile lounges. The parking of aircraft in theapron for loading and unloading can take place under three schemes (Figure 19.2

    1 ):Terminal Building

    .f. 4

    Frontal Parking

    ,

    Satqhte Layout

    5lPier Layout

    Uigurv

    19.21:zGrcfi~l't l'arku12 ~ J S ~ C I I I ~

    1)2)

    Frontal parking Pier layout with right angle or angled Satellite layout.

    3)

    Pier and satellite layouts enable the aircraft to be parked very near to the terminal building. Most modern airports adopt these arrangements.

    19.9 AIRPORT FACILITIES, AIDS AND CONTROLSApart from the handling of passengers and their baggage. an airport has to h a ~

    ~ dcargo le and mail. It has to have facilities for flight catering, aircraft m

    aintenance and fuelling. For controlling air traffic it has to have various a ds like radio equipment and lighting. This section deals with these aspects.

    19.9.1 Cargo HandiingAir freight, both import and export, is expanding at a high rate. This calls for

    mechanised and automated cargo handling facilities. ~ i r f r e i ~is h tcarried in exclusive cargo planes or passenger planes or combi-planes (combination ofpassenger and freight). Facilities that are needed are: 1) Cargo shed where theconsignors deliver their cargo for transhipment and where consignees take delivery of freight.2)

    Cargo warehouses where the cargo is temporarily stored sorted out and processed

    for distribution among various flights.

    3) Cargo apron for loading the freight to the aircraft. Cargo is handled in various forms. It can be palletised, or containerised. or can be handled as a bulk cornnlodity or in units. Mechanical handling by forklift trucks, cranes or conveyors IS usually preferred.

    Handling of mail is done in a similar manner. There should be a separate officefor receiving and sorting outward mail and delivering inward nlail to tn~cks.

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    a

    I9 ,2 Flight Catering t catering is done by various hotels. They have flight kitchen in the city where meals ~oked and packed. They are brought to the aircraftin catering vans and loaded to the ~ fwith t the help of mechanical loaders. Flight kitchens may also be located in the rt itself.

    FII arc alr air

    19 ,3 Aircraft Maintenance FacilitiesAi prc rc1. pa Tb M c aft needs exhaustive checks and maintenance. Maintenance is of various foril~s: :ntive maintenance, routinc maintenance and scheduled maintenance. In addition. a r of damaged aircraft is necessarq. Some of these can be

    done in the apron and ng areas and some other are carried out in the aeronautical engineering base. leronautical engineering base and repair facilities must be

    located close to the apron. :ment of aircraft needing reliairs should not unduly interfere with movement of aircraft. The base should be so planned that future

    expansion requirements are kept :w. There should be adequate supply of fuel, electricity. compressed air, water etc. lgar is a building where aircraft can be parked for maintenance and repairs. The ler and size of hangars are chosen accordifig to the type of the aircraft and their rer.

    fl I!in

    Al nu 1 1 u19

    4 Fuelling Facilities

    A 11 sport must have the system of supplying fuel to the aircraft and the repairs base. F11 is received 111 truck n~ounted tanks and transferred to bulk storage

    tanks. Fuel is then Sill icd to the aircraft either through truck mouilted tankers or through a system of fuel P'F Tll .apacity of the fuelling system must bedetermined from the number of aircraft to be fuc :d and the fuel intake of the aircraft. While small aircraft may take only 5 T of fuel, lar ones may need upto150 T. 19

    5 Ail- Traffic Control Building

    Ail 'raffic Control aids are located in a building, which may be a part of the main tcr nal bullding for small airports or may be a separate unit in case of large airports. Th ~ullding should have space for administrative staff, a control tower, a weather station an( radio centre. When it is constructed as a separate unit. it is located about 50 to 100 m , ny from the main terminal building, almost near the airfield bounda~y, such that all pa1 of the airport are clearly visible.

    19

    6 Airport Lighting

    B11 airports work round the clock. Flight takes-off and land at night as well asdaytime. Ail )st lighting provides illun~ination to achieve this.

    ' co1

    ing is provided at the approach so as to enable the pilot to pick up the landinge. Thc Calvert system is generally used. It consists of six transverse crossbar

    s of llgl placed at right angles to the pro-jected centre line of the runway. Th

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    e crossbars are sp: d at 150 m. They extend to a total distance of 900 111 fromthe runway end. Foi Vl! at l or ba~ tlia ligl 0th ssisting pilots to select proper glide slopes during descent, a system known as tl Approach Slope Indicator (VASI) has been developed. It consists of bars of light s~de of runway, set to show the pilot if he is below the glide path (undershooting), le is correctly established or if he is too high (overshooting). In one form of VASI, )f red lights and white lights on each side of the runway are so beamed by reflectors hen the pilot is too low, he sees all red lights. If he is too hlgh. he sees all whltc .01114 mhen lie is on correct approach he sees red and white bars one above the

    Thl ~seshold of a runway is lighted distinctly by a complete line of lights, generally g1-c

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    Air, Water l'ransports & Other Systems

    Runway lighting takes two forms: c,,lge lighting and centre line lights. The edge lights are spaced at 60 m and centre line light, are spaced at 12.5 m or 15 in. Edge lights a i d centre lights are generally white except for certain zones.Taxiway lights consist of edge light and centre line lights. The spacing of edge

    lights is at 60 In and that of centre line lights is 15 m. The edge lights areblue'and centre line lights are green. A schematic diagram of the lighting system is given in Figure 19.22.Approach Lights Threshold Runway Edge Lights -, / /

    Runwav Centre Line

    ? ................................. . . . . .. .0 0 0 0 0 0 0 0 0 :

    I

    Lightsliigure 19.22: Schematic Diagram of Airport Liyl~tu~::

    19.9.7 Radio EquipmentExtensive use of radio and radar is made in controlliilg air traffic. These instruments are used for air surveillance, weather observation, monitoring of take-o

    ff and landings. guidance to aircraft to reach the terminal area and for facilitating iiistnlinent approach. These have been described earlier in section 19.4.

    19.10 HELIPORTS19.10.1 Role of HelicoptersHelicopters are v.ersatile class of aircraft which can take-off or lald in nearly vertical position. They find extensive use in military operations. For civilian use, they find application in relief and rescue operations. police patrolling,

    and transportatioil of men and materials over short hauls (less than 80 km). For example. between Cochin and Lakshadweep, there is a helicopter surface. Thereis a public sector Helicopter Corporation in India known as Pavan Hans. One of its uses is for passenger transport for oil exploration. In America, helicoptersare used for passenger trailsport in metropolitan regibns.

    19.10.2 Size of HelicoptersHelicopters come in various sizes and seating capacities. Small ones are usually

    1 to 3 seaters and weigh 2 to 5 tonnes. Medium ones can seat 10 to 30 passengers and weigh 5 to 10 tonnes. Very large ones can seat upto 50 passengers and weigh above 13 tonnes. They can travel at 150 to 200 kmlh. Most of them are operated

    by single rotor though designs with two rotors are also found. The rotor diameters are in the range of 10 to 20 m. Ths overall length is in the range of : 10 to 25 m. The height is in the range of 2.5 to 7.5 m. The landing gear consists of

    rubber tyred wheels or skids or pontoons (for landings on water).

    19.10.3 Selection of Site for HeliportsFactors that govern the site selection are:

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    Avoidrmce of conflict with other air traffic Good potential for air traffic Goodcoilnectivity with other transport modes Avoidance of a residential area, whichmay suffer from noise caused by l~elicopters. ters call land on ground, on top

    of buildings .or on the sea (pontoon type landing

    Air Transpurt;ction

    -

    Layout of a HeliportsLanding strip. taxiways Parking areas Loading aprons Teln~iiial bbuding with approach road and parking facility.

    1rt layout has the followiilg components:

    d layout is given in Figure 19.23.Road

    - 1 rAuto Parking Building

    an ding! and Takeoff AreaFigure 19.23: Hellport Layout

    ,metric design standards are given in Table below, which can be read along with19.24. The approach standards are given in Figure 19.24.

    -1

    lSOm AFigure 19.24: Heliport Dimensions

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    Dim~nsion

    1

    Length of landing strip Width of landing strip Width of shoulder Width of taxiway Distance Between centreline of nlnway and parallel taxiway From centre line of

    runway to parked aircraft From centre line of runway to stop line From centre line of runway to building line From centre linc of taxiway to fixed obstruction

    SAQ 3a) What is the hnction of a passenger terminal buildins in a n airport?

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    b) What are the requirements of the following at the passenger terminal'? . i) Passengers; ii) Airlines; iii) Airport management; iv) Community. c) What are the

    components of a terminal building'?d) Give sketches of a terminal building with one-level or two-level operations.

    Air Transportation

    e) What are the arrangements possible for parking of aircraft near a terminal?f)

    What are the facilities needed for cargo handling in an airport?

    g) How is flight catering handled in an airport?

    h) What are "hangars"? i) Describe the facilities needed for aircraft maintenance in an airport.

    j)

    What are the fuelling facilities needed at an airport?

    k) What is an h r Traffic Control?1) Describe the features of airport lighting. m) What is the role of heliports in air transport'? n) Describe some essential features of helicopters. o) What ar

    e the requirements of a site for a heliport? p) What are the components of a heliport'?q) Give a layout for a heliport.

    r) What are the characteristics of STOL aircraft? s) What are the main dimensions of a STOL port?

    Prc Ca: Lo; e the thickness of an airport flexible pavement for an equivalent Single Wheel 40 kN. The subgrade has a CBR of 5. The tyre pressure is 1.4 MN/m2

    SolUsc

    t = thickness in inchesP = load in lb.A = contact area in sq. inIn i

    P = 4 0 x 100 x 0.2204Tyre Pressure=

    1.4 MN/m2 1.4 x 145 = 203 psi.

    =

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    I

    I

    Air ,Water.Trnnspoh & Other Systems

    =14.3 in.=36 cm

    Problem 2Determine the thickness of concrete overlay as per the US Corp of Engineers method over an existing concrete pavement 15 cm thick which is in a good condition.It has been found that a new slab of 20 cm is needed. Also calculate the overlay

    thickness if the slab is badly cracked.Solution:

    Use the formula:

    I

    In this case,C = 1.0 for good condition of existing pavement

    h =15cm

    t?h = 20cm

    For a badly cracked slab,

    C I = 0.35

    19.13 SUMMARYIn this wit, you have been introduced to civil engineering aspects of air transportation. An overview of air transportation has been provided in the beginning of this unit. You have been exposed to the characteristics of modern aircraft that arc needed for designing airports and facilities in them. You have been given

    an idea of the studies made for planning and location of an airport. You have also been provided knowledge& developing the airport layout. You have been explained with the methods of designing

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    y) Kerer sect~on 19.7.1.2.

    r) Refer section 19.7.1.4and 19.7.1.5 s) Refer section 19.7.1.6. t) Refer section 1 9.7.1 7u) Refer Figure 19.10.

    v) Refersection 19.7.2. w) Refer section 19.7.3.x) Refer section 19.7.4.y) Refer section 19.7.5.z)

    Refer section 19.7.6.

    aa) Refer section 19.7.6.bb) Refer section 19.7.7. cc) Refer section 19.7.7. dd) Refer section 19.7.8. ee) Refer section 19.7.9. ff) Refer section 19.7.9. a) Refer section 19.8.1. b) Refer section 19.8.2. c) Refer section 19.8.3.d) Refer Fig 19.20.

    e) ReferFig 19.21.f)

    Refersection 19.9.2.

    g) Refer section 19.9.3.h) Refer section 19.9.4. i)j)

    Refer section 19.9.4. Refer section 19.9.5. Refer section 19.9.7.

    k) Refer section 19.9.6.1)

    111) Refer section 19.10.1. 11) Refer section 19.10.2o) Refersection 19.10.3.

    p) Refer section 19.10.4. q) ~eferkigure 19.23.

    r) Refer section 19.11.1.s) Refer Table 19.10.

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