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Carrying out renovation works while an airport continues to operate is a genuine prowess given the importance of the technical and safety issues involved. And yet this is a choice made by many airports which do not want to, or cannot, close their facility. How can this type of project be conducted, and what risks and difficulties does it entail?
- Crédits : Dushlik - Thinkstock
Deciding whether or not to close an airport to carry out improvement works is a delicate choice for the operator which relies on a certain number of factors. At certain airports, there are no major obstacles to a temporary closure, because the density of alternative airports nearby may allow traffic to be diverted to another destination (for example Beauvais airport in the Paris region). For other facilities, a closure is simply out of the question, either because the airport itself does not have alternative infrastructure (single runway), or because the airport coverage in the region is too poor or inexistent (such as in isolated places such as overseas territories like Tahiti-Faa’a or Fort-de-France). Closing the airport would naturally raise the issue of service continuity: it is thus imperative to conduct work while the airport continues to operate.
In such an event, either traffic is maintained partially over time, with flights arriving and departing at regular intervals after the scheduled works slot (for example night-time works and daytime traffic), or air traffic is limited to a protected part of the airport with, for example, a reduced length of runway and a displaced runway threshold. This arrangement is possible subject to the type of traffic and on the condition that aircraft are capable of operating on half a runway. Emergency services, often operated by helicopters, are however never interrupted on airports, as the work schedule is always adapted to enable the implementation of an emergency chain (civil security, emergency medical transport, etc.).
The operator’s choice is naturally driven by technical and operational constraints, but also by financial considerations since any air traffic restrictions or closures will have a major and obvious impact on the revenue of the airport. The total closure of an airport will generate huge losses, not only for the airport itself, airlines, ground-handling service providers and retail spaces, but also for many stakeholders that are economically dependent on the airport. In 2010, the British Airport Authority estimated that £5 million to £6 million had been lost following the closure of all British airports due to the eruption of the Icelandic volcano Eyjafjallajökull. Fraport assessed the loss at €15 million for five days of closure.
While the choice of keeping the airport open during construction work is very restrictive and often makes the work period longer in relation to what it would be with a closed airport, it nevertheless allows part or all of the airport’s activity to carry on. The programme manager’s challenge is therefore to plan the works so as to cause the least impact on operations while guaranteeing both the best safety conditions and the best operational efficiency. This equation is hard to solve and must be anticipated well in advance.
Successfully delivering improvement works while the airport remains open first relies on a very detailed aviation safety impact study to analyse and finely prepare the means necessary to ensure that the planned works can happen at the same time as airport operations. This stage is conducted under the very strict oversight of the supervision authority and requires close coordination between the authority, the air navigation service provider (ANSP), the ground-handling service teams and the airlines. In practice, the programme manager draws up a works phasing calendar and an operating mode for each of the phases in question, with a risk assessment corresponding to each of them. At each stage, the aim is to foresee and implement ways of mitigating all possible undesirable events so as to fully control all of the worksite’s aspects. During this stage, the airport functions under a totally different system, requiring the production of operation procedures specific to the works phase and enabling the management of the various hazards faced (technical or weather-related).
During this preparation phase, the programme manager takes into account the operational requirements of the operator, airlines and therefore of passengers. The best trade-off needs to be found between the technical constraints of the project and the needs of the airport, and this sometimes leads to flight plans being restricted or adjusted, and airlines temporarily adapting to these as a result. In all cases the safety and quality of delivery are paramount, and these guide the choices of the different operators.
In this type of project where coordination between the airport’s actors is essential to the success of operations during construction work, it is necessary for the project manager to be able to exchange satisfactorily with all of their counterparts in the airport. This requires that they are familiar and conversant with each of their disciplines. A collaborative process is implemented in which all resources are mobilised around a joint objective: delivering the job to schedule while maintaining the same high safety and efficiency levels. Here, the engineer-operator has a genuine added value: its wide range of disciplines means that it is familiar with operating constraints and issues relating to air traffic management, but also that it is proficient in upstream planning phases (taking into consideration operational needs) and downstream phases (coordination with engineering contractors).
Over several months, dialogue must be held in particular with air traffic control services in a common language. Indeed, throughout the works period, 80% of operational coordination happens with the ANSP, exchanging on a daily basis around flight configurations and assessing the consequences of work on controllers’ operational instructions, information and aviation publications. When air traffic is maintained, the ANSP makes aircraft fly over the worksites every day; its teams must therefore be informed in real time as to the progress of works. Furthermore, the programme manager should be in a position to exchange with and coordinate local teams at the airport and the operator’s technical services who are all highly familiar with the airport area. This leads to a win-win interdependence between engineering, which provides its technical expertise and experience in this type of work, and local operators, who have perfect knowledge of the environment.
As with city centre projects, there are high expectations relating to works, from both airlines and passengers, to reduce their impact and make their duration and consequences acceptable. This means that project preparation is similar: before kick-off, the players involved must have detailed knowledge of the premises and technical constraints and be aware of the concerns of the operator and other stakeholders on the platform. Just as with city centre work, this preparatory work must include all local constraints and interfaces between disturbances and use cases so as to be able to compare different possible projects scenarios (schedule, duration, phasing) and thus select the solutions which cause the least nuisance. However, in an airport environment, projects can only be “stealthy” – or unobtrusive - depending on the type of traffic and on how this is spread over one day. For example, in the case of Pointe Noire airport in Congo in 2016, freight planes would usually land during the night, but as runway renovation work was scheduled during the night, this cargo traffic had to be stopped. On the other hand, the work conducted in 2014 in Tahiti Faa’a airport to reinforce its runway and incorporate a lighting system was perfectly “stealthy” because it caused no impact on air traffic. Work took place in two phases: one part of the runway was closed each morning after the departure of the first jumbo jet, but domestic flights were still able to operate during the day. Work then had to stop each evening in order for international flights to resume.
In this project, the equation between project constraints and the needs of the airport is optimised and the engineering works are achieved with the least impact. This solution has also been selected by other airports that are partners of the Egis concession network, such as Abidjan International airport for the refurbishment of its taxiways and its parking aprons.
In each environment, for each configuration and type of traffic and infrastructure, Egis’s engineering and operating teams pool their expertise, backed up by the group’s knowledge of air traffic control. Egis shares and deploys these powerful and effective synergies in all of the programme management and site supervision assignments entrusted to it by its airport clients.