Global InformationStabilised Automatic Bomb Sight information
The Stabilised Automatic Bomb Sight (SABS) was a Royal Air Force bombsight used in small numbers during World War II. The system worked along similar tachometric principles as the more famous Norden bombsight, but was somewhat simpler, lacking the Norden's autopilot feature.
Development had begun before the war as the Automatic Bomb Sight, but early bomber operations proved that systems without stabilisation of the bombsight crosshairs were extremely difficult to use under operational conditions. A stabiliser for the ABS began development, but to fill the immediate need for a new bombsight, the simpler Mark XIV bomb sight was introduced. By the time the SABS was available, the Mark XIV was in widespread use and proving good enough that there was no pressing need to replace it.
The SABS briefly saw use with the Pathfinder Force before being turned over to No. 617 Squadron RAF, starting in November 1943. This squadron's Avro Lancasters were undergoing conversion to dropping the 12,000 pounds (5,400 kg) Tallboy bomb as a precision weapon, and required the higher accuracy of the SABS for this mission. In this role the SABS demonstrated superb accuracy, routinely placing bombs within 100 yards (91 m) of their targets when dropped from about 15,000 feet (4,600 m) altitude.
The system throughout its history was produced in small numbers, all built by hand. Ultimately the 617 was the only squadron to use the SABS operationally, using it with the Tallboy and the larger 22,000 pounds (10,000 kg) Grand Slam bombs. Some Avro Lincolns also were also fitted with SABS, but saw no operational use.