Documents released last week by the National Archives show that the Soviet Union used civilian aircraft to spy on the UK, with one incident coming very close to home.
Papers released by the National Archives under the 30-year rule include a memo written in late 1981 by the then Defence Secretary John Nott to Prime Minister Margaret Thatcher marked ‘Secret for UK US Eyes Only’.
It explains that the aircraft involved in this intelligence gathering would switch off their transponders before veering off their approved flight paths, with one flight taking in RAF Boulmer on the north Northumberland coast.
The memo reads: “One incident of particular interest took place on 9th November, when an Aeroflot IL62 made an unauthorized and unannounced descent from 35,000 ft to 10,000 ft just below cloud level, to fly over RAF Boulmer, a radar station currently being modernised. It subsequently climbed back to 37,000 ft.”
It then explains that the transponder was switched off during what was clearly a premeditated act.