Engineering Aspects of Contingency

Engineering Aspects of Contingency


The engineering aspects of contingency involve planning for, and coordinating the technical response to, contingency when loss of service in one member subsystem can have knock-on effects across the underlying infrastructure.


The objective is to consider the ways in which systems engineering can both be used to promote effective responses to the technical aspects of contingency events but also intervene to exacerbate or frustrate any response. Careful planning can be used to ensure that engineering management addresses the potential problems created by contingency events.


Provision of modern-day ANS cannot be conducted at the optimum levels without the full range of engineering capability that supports the current system/network. The same range of communications, navigation and surveillance (CNS) capabilities will be equally applicable to support contingency operations but will depend to some extent on an air navigation service provider’s (ANSP) overall approach to contingency as expressed through its policy and operational concept for contingency. In-built technical/engineering resilience through the provision of redundant and fall-back equipment/systems should provide the necessary capability for ANSPs to deal with all but the most catastrophic engineering or technical outages and enable them to cope with emergency and degraded modes of operation. However, depending on the scenario, the engineering and technical provisions for service continuity type operations will need to be pre-planned in line with the organisations approach to contingency. It may also be heavily dependent on the approach that it adopts to system engineering. A number of different perspectives can be taken. These are described in the EUROCONTROL Contingency Planning documents - see the EUROCONTROL, Guidelines for Contingency Planning for Air Navigation Services - including:

  • In-House Engineering: engineering undertaken by direct employees of the ANSP.
  • Contractors and Sub-contractors: engineering undertaken on behalf of ANSPs but by external employees of other organisations usually involving bespoke or tailored provision of services.
  • 'Commercial Off the Shelf' (COTS): the use of commercial systems bought ‘off the shelf’ within minimal tailoring or levels of support;
  • Letters of Agreement: these may also include cooperation in engineering between different ANSPs.
  • Cross border infrastructure cooperation: sharing of technical systems including radar feeds in the event of failure or during normal operations.

It is not feasible to provide guidance on every aspect of system engineering as it would affect contingency operations. However, a list of the essential considerations covering CNS and other technical requirements is provided in Section 9.2.2 of the Guidelines. These include:

  • Air/Ground Communication.
  • Ground/Ground Communication.
  • Surveillance Infrastructure.
  • Flight Data Processing
  • Environment Data Processing
  • Surveillance Data Processing

For some European Civil Aviation Conference (ECAC) states it may be necessary to obtain state technical and engineering support for national critical infrastructure projects - for instance some service providers rely on communications and data cables that either pass under international waters or that have to be routed through third party states. Contingency provision may require the laying of fallback cables or the development of satellite communications channels - it can be difficult for ANSPs to implement these strategies without significant political support - for example in cases where there are regional disagreements over the communications satellite constellations that may be used to support service provision.

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