Scrambling (military)

In military aviation, scrambling is the act of quickly getting military aircraft airborne to react to an immediate threat, usually to intercept hostile aircraft.

The term was used during the Battle of Britain, when Royal Air Force fighter pilots waited on the ground for Chain Home radar observations to detect oncoming enemy aircraft. Then, a telephone call would reach each fighter airfield (part of the Dowding system) and those air crews available would be scrambled. Every minute lost before takeoff would be advantageous to the enemy, as it could allow a pilot to gain extra height above the advancing plane formations.

Information passed to the scrambling fighters included location and height (Angels, the origin of Angels One Five for aircraft approaching at 15,000 ft) and a rough estimate of numbers. Unidentified aircraft were known as , and known enemy ones were called . The scramble order was communicated to alert pilots at the base by the loud ringing of a bell.

During the Cold War, many NATO air forces had crews stationed in Europe on alert and scrambled whenever their airspace was penetrated. The rudimentary bell-ringing communication was eventually replaced by electronic radio communication methods. However, many fighter squadrons into the current era would keep a bell at their squadron bar in legacy to the Battle of Britain roots. A common tradition was that if anyone at the bar rang this bell, they would be required to buy a round of drinks to all present.

Both interceptors and nuclear bomber forces were kept on "Quick Reaction Alert" (QRA). Crews were kept close to or in their aircraft, which were expected to be able to take off within a short period, such as 15 min, less than normal situations. It could be only 2 min at times of heightened tension between the opposing powers.

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