The term was used during the Battle of Britain, when RAF fighter pilots waited on the ground for Chain Home radar observations to detect oncoming enemy aircraft, at which point a telephone call would reach each airfield (part of the Dowding System) and those air crews available would be scrambled. Every minute lost before take-off would be advantageous to the enemy, as those minutes could have allowed a pilot to gain extra height above the advancing plane formations. Information passed to the scrambling fighters included location and height (Angels - hence phrases such as Angels One Five for aircraft approaching at 15,000 ft) and a rough estimate of numbers. Unidentified aircraft were known as bogeys while known enemy ones were called bandits. The scramble order was communicated to alert p