A few weeks back there was a bit of traffic on this site regarding the Aircraft Detection Corps. I had an opportunity to a to talk with a couple of men who were engaged in this service and have learned a bit. The Aircraft Detection Corps was active during WWII. It was made up of civilians with an Air Force Officer at its head. There were many observers with a coordinator in each district. Observers had direct access to a communications centre. In those days of multi-party telephone lines, an observer had the authority to clear the phone lines of callers. One local observer's call sign was 'Hilltop 170'. Each observer had field glasses and a collection of flash cards, each with profiles of various aircraft. It appears that they also learned to identify aircraft by sound. It seems that although all aircraft were noted, not all were reported. Air traffic in the area of Windsor, Nova Scotia was, for the most part, East and West with the fighter trainers from Stanley Flying School exempted. My contact told me that on one occasion he spotted two strange aircraft flying low from the South West to the North East He identified them and immediately notified the Communications Centre. It appear he rather enjoyed ordering some gossips off the party line. Within a few minutes he was talking to an Air Force Officer who grilled him on his sighting. Turns out they were two American planes from an air station in Maine; apparently sent out to test the system. They flew the length of the Province and were reported by two observers; one near Yarmouth and my contact near Windsor. At the end of World War Two, the Aircraft Detection Corps was dismantled. however, within a few year in the early days of the Cold War, another system named the Ground Observer Corps was established. This time each observer was given little book (blue or black) that showed the profile of planes. I don't know how long this unit lasted, although I can remember seeing a copy of the book, sometime in the early 1950s. John John D. Wilson Windsor, NS