The concept of a remote aerodrome service for one or more airports is not a new concept. The concept was first thought of and discussed in the late 1990’s and since then has been the topic of much discussion, both for and against them.
As countries began to commercialise their Air Traffic Services and start to charge for services, ways were looked at to make these services both more efficient and also more modern and productive. The balance was to provide a better service, whilst efficient use was made of personnel and equipment. Various ways were looked at and after much thoughts and consultations, the concept of a remote aerodrome service came into being.
The concept of aerodrome services being provided from one centralised facility gained popularity and many countries were involved in the research and development of them. In 2002, the German Airspace Centre, based in Cologne produced a paper detailing their concept, using remote closed circuit television cameras situated at various parts of an aerodrome and then transmitted, live, to a remote facility. Old “die hards” were not impressed with this idea and there was much resistance to it. However, with modern technology and high speed internet links, it was soon possible to relay a good picture of an aerodrome to an off-site facility. Remote radio relays were included, as is common now – forward VHF relays are used in many FIRs to increase VHF coverage and with remote monitoring of ground and navigation facilities, as is done now at many ATCCs, it was soon possible to develop a remote aerodrome control facility.
Apart from the Germans, the Swedish Air Traffic Services were in the forefront and development and research.
In March 2009, Saab Group and Luftfartsverket (LFV) carried out a live shadow mode demonstration of their existing remote tower concept. This demonstration took place at a remote tower centre facility established at Malmöair traffic control centre (ATCC), controlling a flight in and out of Angelholm airport (ICAO:ESTA) in southern Sweden. As a contingency mechanism during this trial, the local control tower at Angelholm was staffed by ATCOs.
In 2010 DLR carried out the first human in the loop remote tower centre simulation, where a remote controller operated traffic at two different low frequented airports simultaneously. Despite several biases the controllers' situation awareness was over-average and their workload remained in average range and operational feasibility could be shown the first time. The initial resistance was overcome, and it proved possible to provide a safe service at two airports from one facility.
Having proven that such a service could be offered, and it be done safely and efficiently, resistance to remote services waned and soon other countries were also looking at developing such a service. Approach and Area services had, for years, been done successfully and safely from remote centres and they proved to be efficient and safe, offering a safe, orderly and economic service to airlines and aircraft operators. Much of the information used to develop these two services was used to develop remote and off-site aerodrome services.
Various models and concepts were researched and developed. These included: One controller working one airport at one facility, or One controller working two or more airports from the same remote facility
Many factors had to be taken into consideration. Some of these problems are manageable and with development can be overcome. However, some are of a legislative nature and require considerable effort to implement and then manage.
Human Factors relating issues such as new technologies, interpretation and transfer of data and application of separation are changing proven standards, and procedures, of tower air traffic control and the need to be them. New procedures are constantly being developed and improved on.
Increased fatigue (eyes fatigue, alarm fatigue etc.) due to a prolonged exposure to artificial light/air and digital prompts should be considered and mitigated. A common problem with any job that uses computer screens and the impact of health on those that use them.
In a manned tower, the controller would sit in one position and look around. This is not possible in a remote tower and so different airspace configurations, procedures, meteorological conditions and other aspects, can potentially create confusion if a controller is to provide service sequentially or simultaneously in more than one facility without enough time to adapt
In case of sequential operations, the controller is probably expected to make an extra effort to adapt to each airport every time
Frequency and Working Positions
The effects of different layouts of simultaneously controlled airfields have been only tested in simulators, where the impact is likely not the same as in real-life traffic handling with real responsibilities and workload. The aspects of frequency handling and working position layout needs further Human Factor analysis and testing. A controller requires training at each and every position they work at. And also, ideally, on-going recurrency training. This would, or has the potential, to be difficult, if a controller is working two or more towers, often at the same time, or on different shifts.
There are still no specific indications on conversion/transition training. No standards appear to have been defined, even in place where remote towers are operational. The same goes for on-the-job instructors and supervisors in remote towers. There is a need for standardisation, world-wide and ICAO would be required to develop such standards, based on information gathered from initial users.
New controllers will likely be directly trained in a digital environment. A conventional training would be useful to fall back to a traditional method of control. Experiencing the airfield live benefits the controller’s ability to assess situations, for instance in relation to relevant weather at the airfield.
License and Endorsements
No specific and globally recognised practices are in place for licenses for remote operations, nor for limits on the number of unit endorsements and minimum requirements to hold them. Civil Aviation Authorities, and indeed, ICAO would have to develop the necessary license requirement and standards necessary to staff them.
Many current displays have a that range that typically spans 240° to 270°. Having the full 360° coverage is desirable and should be part of evolving towards an improved overall view and awareness for the ATCO. But this is an idealistic situation and could involve wrap around screens with a controller sitting at a desk in the middle. Often not possible and feasible
Images can be distorted due to projection of a panoramic view on a flat screen. The use of an arced arrangement of the displays to replicate a real environment without distortion is desirable. This is being partly overcome, by the development of curved television displays.
The refresh rate of images must be high enough to minimize the controllers having the illusion of discontinuity on the screen. A very high speed internet link is required.
All information relies on a digital flow of data. Maintenance and an appropriate check-list for controllers should be put in place. Systems must be developed to prevent the system being hacked into, and at worse shut down.
The airspace design should be analysed and adapted where necessary, especially in case of multiple tower solution implementations.
The presence of mixing IFR/VFR traffic at more than one aerodrome is particularly challenging to manage. Solutions based on limiting access to VFR have been proposed, but this would prioritize the needs of the service above the need of the airspace users and are therefore not recommended.
Ideally remote towers would first be developed and installed at VFR only airfields and slowly developed to included mixed operations facilities.
There is indeed a need for such remote facilities but the various ATS operators need to develop their plans and safety cases properly and safely before progressing to the next stage.
Benefits would include:
1. No need to spend capital building towers are aerodromes
2. Better and efficient utilisation of staff and facilities. The staff could be better utilised at one facility as opposed to having them at many facilities far apart and hardly handing many movements in a shift
3. Costs can be saved, as it would be possible to offer a remote service outside the normal hours of the aerodrome, should such a service be needed. Again, better utilisation of staff and facilities
To date, the following services, in the following countries are provided:
• Sweden has already two operational remote towers. A Remote Tower Centre (RTC) is currently being built in Stockholm.
• Norway is planning a RTC in Bodø, which can accommodate up to 16 AFIS and ATC units.
• Germany is about to launch the RTC in Baden-Baden for three airports.
• In the UK, Cranfield is the newest implemented remote tower in Europe.
• Hungary has a back-up(contingency) remote tower in Budapest.
• Asia is using the remote tower technology to enhance the service in conventional towers.
• In the rest of Europe and the USA, test platforms are up and running. Some countries have already included plans in short-term industrial business plans. Those countries include Italy, Finland and others.
ATNS has put the topic of remote towers on discussion, and it appears that they could well be developed, and such a service provided in the long term future. Interestingly ATNS, has two area and approach simulators, at Johannesburg and Cape Town, and these can be used as disaster recovery units, should the area centres fail or not be possible to be used (i.e. the building has to be evacuated or damaged by fire).