L-1011-600 Bistar/Dash 600
IRL Background:
Lockheed's first foray into a twin-engine Tristar derivative began in 1973 with the CL-1600. Evolving into the Dash 600 by the late 1970s, the aircraft was part of a scheme of Tristar variants which included the unbuilt -300 (further stretched), -400, and -500F Freighter. Ultimately, in our timeline, none of these aircraft were built.
AU Background
With seating for 175-200 passengers, depending on class configuration, and a range of over 2,700 nautical miles, the Dash 600 first flew in in late 1983. Orders came in from a handful of operators, all also L-1011 operators, including Air Canada, Eastern, Delta, Pan Am, and TWA. Deliveries began in early 1985, with Eastern taking delivery of their first aircraft in late January. While not as popular as the Tristar itself, the Dash 600 provided useful engineering and market data which would pave the way for a full series of twin-engine airliners in the future. Ultimately only a little over 30 Dash 600s would be built, with the last passenger aircraft being withdrawn in the mid-2000s as new narrowbody aircraft took their place. Two Dash 600s were converted into freighters for Arrow Air, flying in that capacity until 2006.
Dash 600 Blank (w/gear)
Air Canada
Delta Air Lines
Eastern Air Lines
Pan American World Airways
Used for Internal German Service (IGS) between West Germany and West Berlin.
Trans World Airlines
Arrow Air/Arrow Cargo