Reminded me of the seemingly endless exercises we had at Wattisham in the mid to late 80s. I'm pretty sure during one of them I heard that Leuchars had put Q9 up (?) for real.
We used to be able to listen in to Neatishead on the squawk box on the wall in the management cabin. There were many amusing messages passed back to us when we first moved onto the HAS site when people thought that it was an intercom from the cabin to the HAS
