Arguably the world’s first mega terminal providing an at-the-time unheralded 550,000sqm of space under a single roof opened at Hong Kong International Airport in 1998.
How times have changed, as since then terminals of this size have become commonplace at major hub airports.
And recent years have also seen a trend towards the consolidation of multiple terminals into fewer, larger terminals.
Airports need to be forward-thinking in the facilities that they develop, providing capacity in line with projected growth.
Effective demand forecasting is essential to the business plans of airports, as annual passenger numbers drive revenues that in turn fund facilities. However, the size of facilities is often driven by airline schedules and the demand profiles they generate.
While airports usually take a long-term approach to investment, some airlines often focus on the short-term year ahead. Finding a solution that is acceptable for all parties is anchored in stakeholder management.
With the cost driven by airline schedules, the ability to consolidate activities leads to inherent efficiencies. Airports with multiple terminals need more facilities as the flexibility to share peak activities is not possible. Consolidation of two terminals into one can save between 15-25% on facilities.
Airports with fixed airline assignments, such as those found in the US, are even less efficient, exposing the airport to uncertainties of airline growth, wasted infrastructure and unnecessary operational costs.
Large terminals have inherent flexibility in the assignment of gates, providing a higher level of pier service, which is a key airline and passenger service quality requirement.
The use of multiple centreline stands is becoming widespread best practice, further enhancing flexibility at little additional cost.
Operational costs, in particular staffing, can be significantly reduced in consolidated terminals. Services such as security, immigration, customs, baggage handling, cleaning and maintenance and airline support will require fewer staff to handle the same number of passengers. This saves money for airlines, the airport and government services.
The consolidation of terminals at Heathrow is a good example of this, with the potential of five terminals being merged into three, allowing additional traffic to be handled more efficiently.
Consolidated terminals also produce greater commercial benefits. Retail yields are a central part of funding new airport infrastructure – 10% of the terminal space can pay for the majority of the terminal.
Around 15-20 million passengers per annum are needed to provide optimum performance in product offering, sales and yields.
Bigger terminals offer better retail yields and subsequently lower user charges. Terminals with smaller throughputs offer smaller sales but with higher overheads.
Retail is also an integral part of the passenger experience. Supported by larger food courts, commercial zones have the potential to create a critical mass of space with a ‘wow factor’, making it more preferable to passengers than other airports.
Another benefit of consolidated terminals is that they provide one entrance for passengers whether they are arriving, departing or transferring. This leads to simpler wayfinding and reduced connection times, although very large terminals need to make sure that internal walking distances are minimised through the use of travellators and people-mover systems.
But for many airports it is not always possible to build a new large terminal due to spatial constraints and the write-down costs of existing assets.
Larger terminals will usually cost more to build per million passengers handled than smaller terminals due to increased mechanisation of passenger and baggage facilities. However, they crucially cover significantly less land, allowing for maximisation of airport capacity.
This is one of numerous factors potentially mitigating against the trend to go big. Larger terminals can also create other challenges, including low-level wind turbulence.
Analysis undertaken by the Flight Safety Foundation shows that 85% of crosswind incidents occur at landing and that the design of large buildings can materially influence airport safety.
ICAO’s Aerodrome Meteorological Observing Systems Study Group continues to actively research this topic, as objects such as hangars and terminals not only influence the anemometers but also have an impact on the representativeness of the reported wind.
Another challenge of developing large terminals is providing the intimate space that smaller buildings offer, which passengers enjoy, such as the terminals at Singapore Changi and Amsterdam Schiphol.
However, attention to detail and careful spatial planning have developed some of the larger terminals, such as Heathrow T5, into places where passengers want to be.
Large terminals provide the opportunity through scale and the use of emerging technologies to improve operational performance. End-to-end tracking of bags using radio-frequency identification, either directly applied or through individual carrier baggage systems, provide greater traceability and fewer delayed bags for departures, transfer and arrivals.
Meanwhile, fully integrated control and surveillance systems offer less invasive management of passengers, for example through use of smart wayfinding and tracking.
Smart controls can also help optimise the energy demands of the buildings by cooling or heating where people are gathered and applying less stringent heat, light and ventilation criteria in non-active areas.
Sustainability targets are essential to identify opportunities for incorporating elements in a terminal’s design that can enhance environmental efficiency and minimise the project’s impact on the environment over its whole lifecycle.
Airports such as Hong Kong run green performance indicators across their projects measuring overall reduction in energy consumption and carbon emissions.
Efficiency in design and operation is being driven by increasing energy costs and the realisation that major efficiencies are achievable. Leading developer and operator TAV carries out detailed thermo-imaging of its existing terminals to identify thermal bridges that pipe heat into the buildings, in particular through shading devices on hot facades and fixed-link bridges.
Many fixes such as the introduction of thermal breaks, insulation of cooling towers, high-speed roller doors and ultraviolet reflective materials have been found to give payback within one year.
In many countries tri-generation plants supplying electricity, cooling and heating to large terminals contribute significant gains in operational efficiency.
With scale come opportunities for economies of scale. A new means of driving efficiency in infrastructure development is measuring the embodied carbon associated with construction, maintenance, refurbishment, cleaning and utilities supply.
Quantifying the carbon and cost associated with materials, transport and site activities, identifying carbon hot spots and comparing options will systematically drive efficiency in time, cost and environment impact.
It’s clear that operational and cost efficiencies, as well as improved commercial income, will continue to lead the development of large terminals. What the aviation sector must remember is the potential for magnifying those efficiencies through intelligent space planning, technology and carbon-saving solutions.