than allowing valuable compressed air to escape, although fuel consumption at low speeds is relatively unimportant. Further increases in pressure ratio, demanded by government procurement agencies and commercial airlines for long-range aircraft, caused a bigger mismatch of flow areas/density changes and blade angles. Two approaches were followed: slowing the blade speeds at the front of the compressor by splitting it into two separately rotating parts (spools) or making stators variable on the first few stages as well as the inlet vanes. A disadvantage is significant mechanical complexity as each stator blade has to be independently rotated to the desired angles. Two spools need more bearings and turned out to be heavier. Bleed valves, two or three spools and variable stators are all used together on modern engines to cope with rotating stall during starts and at low speeds and to allow surge-free fast accelerations. Rolls-Royce considered the variable stator idea in the 1940s, but abandoned it until using it in the 1980s on the V2500 engine. They began development of two-spool designs, a concept that was also selected by Pratt & Whitney. The variable stator path was only selected by GE after a year-long design study competition comparing two spools and several stages of variable stators with objectives of efficient performance at cruise Mach 0.9 and at Mach 2, increased thrust, reduced fuel consumption and weight. The J79 emerged as a powerful, lightweight design 2,000 lb lighter than its 2-shaft competitor for the B-58, the J57 engine, and GE began considering it as the basis for a high-power engine for commercial use. CJ805 program In 1952, Chapman Walker's design team at GE built a one-off prototype of a jet engine designed specifically for transatlantic airliners. It used a single-stage fan powered by the same turbine shaft as the main engine compressor, as opposed to the Pratt & Whitney designs that were using a separate power shaft to run the fan. The GE design proved to be difficult to start and operate and was not developed further. In 1955 Jack Parker took over GE's Aircraft Gas Turbine division. He hired Dixon Speas to begin interviewing executives at airlines to try to get a sense of the future market. Parker asked Speas to interview not the CEO's, but executives that might be the CEO by the time GE was ready to enter the civilian jet engine market. Parker, Speas and Neil Burgess,