5
C H A P T E R
and scope of future expansion, and to be flexible enough to meet reasonable objections.
As airports transfer from state to private ownership (the result of the worldwide trend towards airport deregulation and removal of government subsidies), the new owners have begun to recognize the importance of the physical masterplan in realizing the land assets at airports. Much land at the
perimeter of airports has in the past been poorly used, but under new management the potential for development has tended to be seized. New non-governmental airports tend to see peripheral land as a means of raising cash to subsidize improvements elsewhere, perhaps to terminals or runways.
The masterplan helps in realizing the capital tied up in the land itself by identifying surplus land and by creating the right balance of adjoining land uses and infrastructure to maximize its value. The masterplan is therefore both a technical statement of potential and a means of raising expectations and worth, which helps in increasing the valuation of land assets. BAA’s use of masterplanning around Glasgow Airport is a notable example of planning-led land utilization and asset enhancement.
The development plan as a final concept will have needed to be assessed technically, politically and procedurally. The formulation of the masterplan, involving a variety of concepts and options, each subject to economic, technical, social and environmental evaluation, will harden into a development plan for consultation. Those who compile the masterplan will, armed with surveys, facts, trends etc., be asked to justify the plan before public inquiries of one form or another. The masterplan needs to be convincing, candid in its analysis of problems, and clear in its forward vision.
Airport masterplans are continually updated documents. In an industry of rapid change, the plan should be monitored and adjusted frequently, perhaps every year. There should be regular adjustment to ensure that changing national laws (on say environmental protection) and altering government policy (on say the balance between road and rail investment) is reflected in the airport masterplan. Also, the plan needs to be adjusted in response to socio-economic conditions, to changes in national air transport policy, to the amalgamation of major airline companies, to alterations to regional land-use policies, and to changes in the design and management of aircraft themselves. As in much forward planning the parameters are subject to change, and this necessarily alters the assumptions from which the masterplan was evolved.
In the UK the government White Paper of 2003 on the future of the aviation industry expects a threefold increase in passenger volumes by 2030. This growth in demand requires imaginative forward planning.
Masterplanning airports
5.1 Conceptual clarity is the key to the airport masterplan. Notice how the geometric order in the masterplan is reflected in the architectural order of the design of the terminal. Antalya Airport, Turkey. Architect: Dogan Tekeli-Sami Sisa.
Intermediate plans
The masterplan is a framework for development in space and time. Within the full plan period (usually 20 or 25 years) there should be intermediate plans based upon five-yearly increments. Major development (such as runway expansion, enlargement of a terminal or ground transport provision) should correspond with these intermediate plans, thereby allowing financial and facilities planning to proceed smoothly. The aim is to produce a long-term vision that can be implemented on the basis of well-specified incremental growth.
These intermediate plans provide both the framework for airport expansion and the means to monitor and modify the full airport scheme. Over the plan period the assumptions upon which the masterplan was based will have changed. There may, for instance, be a different pattern of passenger use, a new generation of aircraft design, and changes in government policy to air transportation. Hence the staged provision of airport facilities may need modification. The role of the masterplan and its intermediate plans is to ensure that the totality of the airport design is sufficiently flexibile to cater for the unexpected.
Compiling the masterplan
A masterplan is needed for existing and new airports. Both are subject to the same pressures, and will need to follow similar procedures in the masterplanning exercise. Generally speaking there are six stages in airport masterplanning:
1. Appoint masterplanning team and establish parameters.
2. Survey facilities and identify issues.
3. Review aviation forecasts.
4. Evolve and test concepts against environmental, financial and regulatory constraints.
5. Formulate plan and simulation (using CAD) for consultation.
6. Modify and adopt masterplan.
Often the masterplanning exercise is undertaken in order to determine whether an airport should be expanded, or whether it is preferable to build a new facility. Here, the plan needs to be concluded with a policy based upon a thorough analysis of existing conditions and forecasts. Keeping an up-to-date Masterplanning airports
5.2 Detailed design needs to exploit the geometry of space to provide incremental growth. Transportation Centre, Seoul Airport, Korea. Architects: Terry Farrell and Partners.
inventory of all the facilities and buildings at an airport is vital if the right choice is to be made between expansion and the construction of a new airport. This is an inventory not only of ground facilities but also of airspace, air congestion and the anticipated growth in air traffic in the region over, say, the next quarter century. The survey will also need to look at buildings and urban areas outside the perimeter of the airport to see how they will be affected. Hence the inventory should contain the location, size and distance from flight paths of hospitals, schools and churches. Noise corridors and cones will need to be plotted, as will historical data on weather patterns in the area.
Existing conditions and traffic forecasts are both important areas of data gathering. Understanding the nature of demand, its profile and characteristics, allows a variety of options over different timescales to be evaluated. Once the case has been demonstrated for radical expansion of an airport or the construction of a new one, the type and scale of facilities can be determined.
Airport layout
The layout of the airport is determined by a number of related factors. As in all design exercises there are no precise rules, but rather the balancing of one factor against another to arrive at the best compromise. The principal factors to consider, evaluate and organize spatially are:1
• number and orientation of runways (especially with regard to meteorology)
• number of taxiways
• size, shape and organization of aprons
• area of available land
• topography and soil conditions
• obstacles to air navigation
• number and distribution of terminal buildings, hotels and car parks
• external land uses
• phasing of development
Airport layout
5.3 Main runway to terminal layout options.
Station
Road Runway
Station
Road
Terminal
Runway Terminal
Runway
Terminal
Terminal
Station
Road
Runway
• size and layout of airport road system
• strategy for public transport connections.
The organization of the above factors into a coherent whole then leads to the selection of preferred locations for such facilities as air traffic control tower, aircraft maintenance areas, railway or metro stations, fuel stores, rescue and fire-fighting services, and control gates. The detailed layout of the airport needs to balance conflicting demands, such as public access and security, air freight and passenger needs, and arrival by car or train.
In the normal planning of airports, a number of options are arrived at, evaluated and eventually rejected. The constraints – operational, financial, and in terms of development phasing – add to the complexity of airport layout design. Because
airports are subject to rapid change in response to innovations in aircraft design, the masterplan needs to be able to accom- modate growth. Both long-term (say 20–25 years) and short- term tactical flexibility (say 5 –10 years) need to be provided without compromising the integrity of the whole design.
Runway layout
A key factor in the layout of the masterplan is the configuration of the runways and the relationship between runways and the terminal building. Two main aspects of runways concern the airport designer: their length and their alignment. Length is dependent upon the type of aircraft using an airport, but for the largest planes a runway length of 2 – 3km is normally required. The length of the runway varies according to altitude, Masterplanning airports
5.4 Major and minor grids are often the basis for airport planning. Munich Airport, Germany. Architects: Prof. von Busse, Blees, Kampmann & Buch with Murphy/Jahn.
temperature, wind conditions and plane weight, so for a given aircraft design different runway lengths may be required at different locations. The critical length on a runway is determined by the safe take-off dimensions, not the landing dimensions, which are considerably shorter.
The capacity of runways is difficult to calculate exactly (it is dependent upon the mix and capacity of aircraft and safety regulations in operation at the time). However, as a rule most runways deal with 45 – 50 operations per hour in good weather and about 25 per cent fewer in poor weather. There is clearly a correspondence between runway and terminal capacity because they both deal with the transport of the same unit of people. To increase the number of passengers handled, airport authorities often extend runways (to allow larger aircraft to land) or build additional runways. These can either be in parallel alignments or more commonly placed at an angle to each other. The advantage of the latter is the greater flexibility in maintaining operations in cross-wind conditions. Where two parallel runways are provided the terminal can straddle them, giving obvious benefit in terms of ready access and economy of airside provision. With angled runways the terminal can sit within the hinge of the runway arms (see Figure 5.3).
For safety reasons parallel runways are usually required to be 2000m apart laterally, and with angled runways the point where they converge should obey the same dimension.
Occasionally runways cross over, but generally divergent runway alignments are preferred. With modern air traffic and ground flight control, airports with two or more runways can handle up to 100 operations an hour, which if translated into passengers (assuming 150 passengers per aircraft) means that the terminal buildings should be capable of dealing with a throughput of 15 000 per hour.
Two or more runways allow airports to cater for simultan- eous landings and take-offs. High-density airports, as in the USA, sometimes employ three parallel runways, each linked to a dedicated terminal building. However, the constraint is not so much air space but taxiing space on the ground. Aircraft have to cross the path of those engaged in take-off or landing, posing the potential threat of collision.
The distance that the aircraft needs to taxi between the terminal building and the runway has a large bearing upon airline costs. Long taxi length means longer flight times, increased fuel costs, and the potential for ground traffic delay.
The relationship between the location of the terminal and that of the runways (and taxiways) is crucial. Different config- urations of terminal buildings, taxiways and runways affect design to a significant degree. There are complex layout issues to resolve, such as airside and landside links (ensuring that smooth connections are made with public transport, for exam- ple), and internal environmental conditions to consider (such as aircraft noise, which is more objectionable with jets because of its higher frequency than with turboprops). Where the terminal is placed between parallel runways it can no longer have a clear distinction between airside and landside, because passengers are accessing aircraft on opposite faces of the building.
Likewise, taxiways that transport aircraft from the runway to the terminal building and service hangars have to be able to cater for aircraft movements in both directions simultaneously.
Physical elements of the masterplan
Airport masterplanning is a team effort, but the architect or engineer is normally responsible for the physical disposition of the parts. This involves three principal elements:
Physical elements of the masterplan
5.5 The growth of the airport over a 50-year timeframe needs to be accommodated in any masterplan. Here at Palma Airport new satellite terminals are planned well in advance of need.
• runways and taxiways
• hangars and service aprons
• terminals
and several secondary ones:
• roads and car parks
• security enclosure
• air traffic control tower
• airport railway stations and light rail system
• hotels, conference facilities etc.
• freight warehouses.
Design is not just a question of the dimensions of the parts in plan but their height and clearance from approach slopes and the like. Similarly, runways have safety zones, and there needs
to be cross-wind provision. Terminal buildings are linked to piers and gate positions, thereby determining the layout of aircraft parking and further safety clearances.
The masterplan is a spatial, logistical and three-dimensional graphic plan, which structures investment in the fourth dimension – time. It is important that the vision of the architect and engineer is reflected in the management of the airport and the needs of the airlines that use it. A number of ground rules exist to provide the operational context for the airport and to help integrate airside and landside functions. As a general rule:2
Runway areas
• Separate airline, general aviation and commuter traffic on apron.
Masterplanning airports
5.6 Original masterplan (left) for Edinburgh Airport by RMJM and proposed expansion (right) incorporating a railway station and new terminals. Architect: RMJM and Douglas Sherman.
• Design for efficient and flexible apron-handling operations.
• Minimize taxiing lengths.
• Locate crash and rescue services close to main runway.
• Encourage joint airline use of airside facilities.
Administration buildings
• Locate airport administration close to road and rail system.
• Centralize administration facilities with direct access to landside and airside.
Road layout
• Keep landside road system simple.
• Provide public transport at terminal kerbside and administration building.
• Locate car parks close to terminals or linked by tram system.
Terminal buildings
• Minimize walking distances.
• Facilitate inter-airline transfers of passengers.
• Separate air carrier functions (international, national, commuter) but provide easy interconnections.
• Maximize marketing and rental opportunities.
• Encourage joint airline use of facilities.
• Link terminal buildings directly to public transport.
• Link terminal buildings to hotels and short-stay car parks.
Warehouses
• Accommodate growth in air cargo.
• Ensure efficient segregation airside of passenger baggage and freight.
• Facilitate cargo transfer between airlines.
The importance of geometry
The movement of aircraft, service vehicles and people, imposes a geometric order upon the airport. Turning circles,
safe distances, flow paths and functional patterns have their own logic in dimension and geometry. Functional order expressed as spatial order is reflected ultimately in structural order. It is characteristic of airports that these orders share common dimensions or physical attributes. Underlying them is a sense of big geometric patterns imposing their will on lesser systems – aircraft turning circles determine the layout of taxiing areas which in turn figure the spacing of gate piers which then position and help give size to terminal buildings.
Behind these patterns lies a system of geometric and spatial configurations which can be readily identified in plan and exploited by the designer. The architect has the primary task of finding clear organizing patterns which can regulate development over time. Such patterns expressed as structural layouts are best evolved with a clear sense of geometric progression. The geometry of patterns of space usage, of people movement and of structural layout, becomes a frame- work to accommodate the lesser activities (such as retail outlets) and one which can then be extended to accommodate future growth.
A common problem encountered is how to impose this order (essential for economic construction as well as passenger legibility) upon terminal buildings which have grown up in
The importance of geometry
5.7 This design for Seoul Airport shows the benefit of integrating design and infrastructure engineering at an early stage. Architect:
Paul Andreu.
a haphazard fashion. The key lies in organizing traffic flows into a framework of space, structure and light which can regulate both the inherited chaos and impose a will upon the future.
Without such clarity the airport would have little identity as a place. Central to the idea of spatial clarity is that of geometry – the simple but harmonious pattern of repeating linear and curved patterns in isolation or in juxtaposition. The use of geometric order allows the functional and spatial to fuse.
Not all architects subscribe to a simple repeating order but the demands of a harmonious integrated building outweigh the specific interest of a lesser part.
Geometry creates order which aids legibility and image.
The construction of a new terminal may provide the chance to link together existing poorly connected structures within a fresh grand conception. This can enhance navigation through the airport and remove the tendency towards an alienating nondescript airport environment. At airports, as in cities, architects have to find solutions which enhance existing situations. Simple geometry provides the chance to generate added value through grand design.
It is, however, difficult to impose an overall vision at some later stage. If the original masterplan for the airport lacks clarity, the opportunity to generate memorable design may be lost. Partial demolition can sometimes allow for
the insinuation of missing geometric definition – certainly the architect should consider it when re-designing an airport facility. Such geometric order can exist at many levels: it can fashion large spatial volumes and the smallest construction assembly.
Clarity of geometric conception encourages the airport authority to keep the long-term goal in sight while building in small but coherent portions. It also keeps to the fore the importance of spatial clarity when pressures mount for small- scale functional change. The armature of geometry can be a long-term asset if it is established initially in the masterplan and upheld by those who subsequently commission design changes.
Site choice
It is assumed here that the site for the new airport has been decided, but part of the masterplan exercise often involves the selection of an area for airport expansion. Site selection for a new or greatly expanded airport is fraught with difficulties, so much so that often an ideal site does not exist and a man-made one has to be created (as at Kansai in Japan or Hong Kong’s airport at Chep Lap Kok: in both cases physical and environmental constraints were such that an Masterplanning airports
5.8 A clear sense of structural and spatial logic is evident in this design for Algiers Airport. Architects: Von Gerkan, Marg & Partner.
artificial island had to be formed in the sea for the new airport).
The site selection process should include an analysis of the following factors:3
• operational capacity: obstructions from high buildings and mountains, weather patterns and airspace considerations
• capacity potential: land availability and sustainability
• ground access: infrastructure provision (road and rail), centres of population, parking space
• development costs: land costs, soil and rock conditions, land utilization values
• environmental factors: noise, impact upon ecosystems, air and water quality, cultural impacts, endangered species
• socio-economic factors: impact upon existing communities, public service needs, changes to employment patterns
• planning issues: impact upon land uses, agriculture, forestry and transportation systems.
Balancing the above factors leads to the selection of preferred locations, which can then be investigated in greater detail.
Part of the analysis (sieve mapping, contouring and visual
simulation) is normally undertaken using computer-aided design (CAD) techniques. Creating an image of the shape the development will take and its wider impacts helps in the final selection of a site. Interactive computer simulation also allows those affected locally to modify the proposals, thereby reducing community conflict at an early stage in the masterplanning process.
Energy and resources
It is important that the site chosen for the airport has sufficient supplies of electrical power and water, and adequate provision for sewage disposal for the full masterplan period: that is, 20 –25 years. Airport expansion is dependent upon the ready availability of large amounts of energy and other resources.
Future airports are likely also to generate some of their energy needs (by solar or wind power) and to recycle water and waste.
The ecological impact of an airport is enormous, and rather than dispose of all wastes the trend will be towards recycling and energy conservation. Heat recovery from the passenger terminal plant, combined heat and power for electrical generation, and exploitation of renewable sources of energy will begin to influence future airport planning.
Energy and resources
5.9 The spatial pattern across the landscape reflects directly the operation of a modern airport. Notice here how planting softens the impact of the airport. Oslo Airport, Norway. Architects: Aviaplan AS.