Lockheed’s final commercial aircraft, the TriStar was designed to fulfil an American Airlines specification for a 250-seat wide-body airliner for use on domestic routes within the United States. Although American decided to opt for the rival DC-10, Lockheed was able to launch production in 1968, based on orders and options for 172 units from TWA, Delta, Eastern and Air Holdings Ltd., the latter being a company set up by Lockheed and British interests to pacify protectionists alarmed at Lockheed’s use of non-US engines on the aircraft. Early attempts to develop an intercontinental version of the TriStar failed, these adding to Lockheed’s already significant financial problems. Matters came to a head in January 1971 when Rolls-Royce passed into receivership, and the project was only saved after US and British Governments stepped in to rescue Lockheed and Rolls-Royce respectively.
Despite the TriStar’s early success, Lockheed was unable to capitalize and it announced in December 1981 that production would end after completion of the 250th aircraft. Since then, the company has focused on its military aircraft business, acquiring General Dynamics’ Fort Worth Aircraft Division in 1993 and merging with Martin Marietta in 1995. The TriStar remained in commercial service into the 2010s, proving popular with start-up carriers in Africa and Asia. Survivors are therefore scattered far and wide, with only one aircraft remaining active.
First flight: 16 Nov 70 (c/n 193A-1001, N1011)
Production: 250, at Palmdale, CA
First delivery: 5 Apr 72, to Eastern Air Lines (c/n 193A-1007, N306EA)
Last delivery: 3 Jun 85, to Alia Royal Jordanian Airline (c/ns 293A-1246 and 293A-1248, JY-AGI and JY-AGJ)
Variants: TriStar 1 – initial production version with typical accommodation for 256 in two-class arrangement, powered by three Rolls-Royce RB211-22B or -22C turbofans (162 built);
TriStar 100 – higher gross-weight TriStar 1 with increased fuel capacity (14 built, plus conversions from TriStar 1, first flight 28 Jun 75);
TriStar 200 – TriStar 100 optimised for ‘hot and high’ performance, powered by RB211-524B4 engines (24 built, first flight 8 Oct 76);
TriStar 500 – extended range shortened fuselage version based on TriStar 200, with accommodation for 246 in two-class arrangement (50 built, first flight 16 Oct 78).
Conversions: TriStar 50 – TriStar 1 with increased maximum take-off weight;
TriStar 150 – TriStar 1 with further increased maximum take-off weight;
TriStar 250 – TriStar 1 with increased fuel capacity and re-equipped with RB211-524B4 engines (6 converted by Delta);
TriStar K.1 – TriStar 500 converted by Marshall Aerospace for use as tanker/passenger transport, with fixed refueling probe and hose-drum beneath rear fuselage (4 converted, first flight 9 Jul 85);
TriStar KC.1 – 2 TriStar 500s and 2 TriStar K.1s converted by Marshall Aerospace for use as tanker/cargo transport (4 converted).
Additionally, Marshall Aerospace converted a TriStar 1 in 1994 for use by Orbital Sciences as a satellite launch platform; the aircraft has since been re-engined with RB211-524B4s.