Co-located contingency facilities provide fallback services at the same site as an existing ATM facility; these may include area control centres (ACCs) as well as existing training and simulation centres.
Co-located facilities offer significant benefits in contingency planning because staff need not be relocated during an emergency or the service continuity phase of an incident. There are also benefits in terms of the maintenance or facility management of infrastructures that are associated with existing facilities.
Contingency facilities can be developed on the same sites as the primary centres - e.g. training and test suites can be reassigned for contingency. Obsolete systems may also be used as a fallback facility. These applications can be retained on a 'care & maintenance' basis that enables ops teams to use them if the primary system fails; they could also provide considerable additional assurance during operations to 'clear the skies'. There are clear vulnerabilities for co-located systems that arise within particular European Civil Aviation Conference (ECAC) states. For instance, it can be difficult to identify appropriate sites that would not be vulnerable to seismic activity; similarly, for other air navigation service providers (ANSPs), co- located centres may create common vulnerabilities from threats such as flooding. For most service providers, there is a concern that primary and fallback facilities might both be affected by any future aviation accident if they were also both located close to an airport.