Alternative engine from
L-1011 Tristar History
There simply was no easy alternative to the Rolls engines. To turn to Pratt & Whitney for its JT-9D turbofan or to General Electric for its own commercial engine, the CF-6, would cost a year in time and $100 million in development costs. That was because neither of these engines would slip in neatly as a replacement. There would be need for extensive redesign of engine housings and installations, starting with wind-tunnel tests, proceeding through reconsideration of weight distributions