An air traffic controller often needs to speak to pilots by radio, contact another controller by telephone or intercom, and move quickly between different communication channels from the same working position. During normal operations, those connections are brought together by the Voice Communications Control System (VCCS). But however much redundancy is built into the primary system, an airport also has to consider what happens if the VCCS itself or the infrastructure it depends upon becomes unavailable.
That is where an Emergency Voice Communication System (EVCS) has a different job to do.
What Does A VCCS Do In Aviation?
A VCCS is the primary switching system through which controllers access their operational voice communications. In the UK, these systems sit within the scope of CAA CAP 670 – Air Traffic Services Safety Requirements, which sets out the technical and safety requirements applying to equipment used to provide air traffic services. That includes the communications systems controllers rely on to speak to aircraft, vehicles and other ATS units.
In practice, the voice switching and control system brings multiple radios, telephone circuits and intercom connections onto the controller’s operating position, allowing them to select the required frequency or line without needing a separate control interface for every communications path.
Modern VCCS aviation equipment can itself contain considerable redundancy. Our TCS990 digital voice system, for example, can use redundant power supplies, servers and bus signals to maintain high availability if an individual component fails.
So, Why Do You Still Need An EVCS?
Internal redundancy protects against component failures within your main VCCS. An EVCS system adds another layer of resilience by remaining independent of it.
The VCCS Vs EVCS distinction becomes clearer when you look at the failures that can interrupt a primary VCCS:
- A hardware or software fault could affect the central switching equipment.
- Loss of network connectivity could isolate an operating position, radio site or another remote part of the system.
- Electrical disruption could remove equipment that is not supplied through the protected power architecture.
An EVCS uses independent power, dedicated cabling and separate control paths, so a failure affecting the primary VCCS is less likely to take the emergency system down with it.
That principle has been applied successfully at Heathrow, for instance, our engineers worked with NATS to install an MEP TCS990 configured specifically as an EVCS, providing a system intended to remain available if the airport’s main VCCS fails.
Build Resilience Into Your ATC Voice Systems
At Copperchase, we design and install both primary VCCS and independent EVCS solutions, allowing the two systems to be engineered around the communication requirements and infrastructure of your airport.
From radios and telephones to operator positions, power and network paths, we can help you identify where the primary system depends on shared infrastructure and build an emergency communications route around those dependencies. Please contact us today to find out more.
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