Fortunately, between the end of the Cold War and 9/11, Britain’s air defences had to deal with few red alerts. The Chief of the Air Staff, Sir Glenn Torpey, recently confirmed that, prior to 2001, there had been a long period of ‘zero’ scrambles for the RAF’s Tornados since the end of the Soviet threat in 1990. 1 Today, fighters are only scrambled to intercept aircraft entering UK airspace that might pose a threat, but during the early part of the Cold War they were frequently sent up to identify UFOs and ‘angels’ detected on radars. But after the source of the ‘Radar Angels’ was identified (FT195:36–37) modern military and air traffic radar systems were designed to ignore unusual returns that do not behave like aircraft.