Oboe: a precision ground-controlled blind-bombing system

The system of ground-controlled blind-bombing used by the Pathfinder Force of Bomber Command of the Royal Air Force since December 1942, and later by the United States IXth Air Force, is described in detail. The system enables an aircraft flying at a height of 30,000 ft to be controlled from pulse ground stations up to a range of nearly 300 miles, and to drop its bombs with great accuracy. Trials undertaken on bombing ranges in this country show that for an aircraft flying at 300 m.p.h. at a range of 110 miles, the average radial error for bombs dropped from 6,000 ft is 45 yd, and for bombs dropped from 25,000 ft is 100 yd. For a similar aircraft flying at a range of 250 miles the average radial error for bombs dropped from a height of 30,000 ft is 150 yd. Of the bombing error about 10% is taken up by the system errors, 45% by flying errors, 30% by inaccuracies in meteorological wind forecasts and 15% by bomb ballistic errors.