The Lockheed L-1011 TriStar is an American medium-to-long-range,  wide-body trijet airliner that first flew on November 16, 1970, and  entered service in April 1972 with Eastern Airlines. However, engine  delays and the financial problems of Rolls-Royce delayed the TriStar’s  entrance into service by two years, allowing the McDonald Douglas DC-10  to reach the marketplace first.

The Tristar utilised advanced  technology to allow it to be the first widebody airliner certified for  blind autolanding. Production ended in 1984 with 250 airframes built,  needing 500 to break even financially; Lockheed withdrew from the  commercial aircraft market. The British Royal Air Force operated nine of the type, designated K.1, KC.1 and C.2, used in the tanker, passenger  and cargo roles.

The airframe is mostly an aluminium alloy  structure with a semi-monocoque fuselage and low mounted cantilever  wings. The tail is a standard single fin layout. The retractable  undercarriage is a tricycle type with the main units mount in the wings, folding inwards into the fuselage; the nose unit retracts forward. It  has a flight crew of three, two pilots and a flight engineer with  seating for up to 300 passengers depending on variant.

It is  powered by three Rolls-Royce RB211 high-bypass turbofan engines, one pod mounted under each wing and the third in the rear of the fuselage, air  fed via an S-duct embedded in the tail and upper fuselage. The L-1011-1, the first production model, had a cruise speed of 963 km/h (598 mph)  with a service altitude of 12,800 m (42,000 ft) with a range of 4,963 km (3,084 mi).