Air Traffic Control Recording

The Civil Aviation Authority control each Airport in the UK, and required the use of Instrumentation Recorders to record all communications between the ground and aircraft under its control, and the associated Radar Signals.

These suffered from the same reliability problems, and required 3 systems to be at each airport. One recorder would be on line, one in standby, and one available to replay the recorded tapes.

Each day the reel of tape that had recorded yesterdays Audio and Radar had to be removed and placed in a store and kept for 32 days. The tape which had recordings on which were more that 32 days old was erased and installed on the recorder to capture that days Audio and Radar.

The Civil Aviation Authority approached Avalon Electronics to design a replacement for these three recorders, with Disk Based units. Instead of a Voice trigged recording approach, as these had failed in the past, Avalon decided to record all channels continuously with 16 bit ADC resolution, to ensure every last noise was accurately captured.

Two Disk Recorders were supplied for each Airport with both running continuously, to provide dual redundancy. This required no operator intervention to achieve continuous recording. The Disks cycled around the entire space, recording over the old data after 32 days.

If an incident occurred, instead of having to get a tape out of the store to investigate the event, data could be copied immediately to USB Drives whilst the recordings continued. The copies of the data of interest, usually the recordings 24 hours either side of an incident, can be recovered from any period within the 32 days.