The Bizarre Rear-Fan Engine That Killed The World's Fastest Airliner

The article traces how General Dynamics’ Convair 990 Coronado chase for speed—and General Electric’s decision to build an aft-fan turbofan, the CJ805-23—ended in failure. Built between 1961 and 1963, the 990 was derived from the shorter Convair 880 at American Airlines’ request, aiming to raise seating from 88 to 110 passengers (or 96 to 121). Compared with rivals like the Boeing 707 and Douglas DC-8, the Convair 990 cruised about 25 to 35 mph (40-56 km/h) faster, yet carried fewer passengers and struggled with operating costs and fuel efficiency. The piece also frames the broader mid-century debate between future supersonic airliners and turbofan efficiency, which ultimately favored different paths.