The Lockheed L-1011 TriStar, commonly referred to as the L-1011 (pronounced "L-ten-eleven") or TriStar, is a medium-to-long-range, wide-body trijet airliner by Lockheed Corporation. It was the third wide-body airliner to enter commercial operations, after the Boeing 747 and the McDonnell Douglas DC-10. The airliner has a seating capacity up to 400 passengers and a range over 4,000 nautical miles, Its trijet configuration has three Rolls-Royce RB211 engines with one engine under each wing, and a third engine, center-mounted with an S-ductair inlet embedded in the tail and the upper fuselage. The aircraft has an autoland capability, an automated descent control system, and available lower deck galley and lounge facilities. Between 1968 and 1984, Lockheed manufactured a total of 250 TriStars, assembled at the Lockheed plant located at the Palmdale Regional Airport in southern California north of Los Angeles. The aircraft's sales were hampered by two years of delays due to developmental and financial problems at Rolls-Royce plc, the sole manufacturer of the TriStar's engines. After production ended, Lockheed withdrew from the commercial aircraft business due to its below-target sales.