This is the first foreign-made engine chosen as the basic power plant for a major U.S.-built airliner, the Lockheed L-1011 TriStar, receiving its certification from the Federal Aviation Administration in 1973 for use on that three engine aircraft. In addition, it powered some models of the Boeing 747 transport.The RB211 differed from other engines in its class in having three instead of two shafts. Each shaft has a compressor on its forward end and a turbine on its aft end. This design permitted each compressor to run nearer its optimum speed and efficiency and reduced the number of blades and other parts required in the engine. The static thrust varied from 160 KN (36,000 pounds) to 245 KN (55,000 pounds).This RB211-22 engine powered the Lockheed L-1011 TriStar. It has been cutaway to show the relationship of the internal parts.