From the Lockheed-California Company of Burbank, California:
Visible in the yawning mouth of a Rolls-Royce RB.211 turbofan engine is the huge fan which can be slowed during a jetliner's landing approach to reduce noise detected on the ground. The engine, which will power Lockheed's new L1011 TriStar jetliner, is undergoing development testing at Rolls-Royce facilities in England. The RB.211 shown above is being prepared for operation in a newly completed open air test bed at Rolls-Royce's Hucknall Flight and Test Establishment at Nottingham. The new test bed was designed specially for testing of the RB.211's noise suppression features, in addition to normal performance testing. The TriStar, equipped with three RB.211s, will make its maiden flight from Palmdale, Calif., in 1970.