* The development of turboshaft engines in the 1950s provided truly adequate powerplants for heavy-lift helicopters. Using such improved technologies, the Sikorsky company developed a series of large turbine-powered helicopters, beginning with the twin-engine "S-64 Skycrane", which led to the twin-engine "S-65 Sea Stallion" and then its three-engine derivative, the "S-80 Super Stallion". This document provides a history and description of the Sikorsky S-64, S-65, and S-80. A list of illustration credits is included at the end.
