The fixed shaft constant speed variable torque turbine

Extract

Since 1946 I have been convinced, from the viewpoints of safety, economy and simplicity (facilitating calculations and development) that the most rational solution to nearly all aircraft propulsion problems is the Fixed Shaft Constant Speed Variable Torque Turbine.

But as the engine manufacturer is not the only judge of the propulsion systems adopted by the airframe manufacturers, I have been and still am therefore obliged to manufacture engines, the technical and commercial success of which I do not deny, while being convinced that more rational solutions exist. Because of this Turbomeca has manufactured, and continues to manufacture—alone or in co-operation with other engine manufacturers—free turbines, pure jets and twin shaft by-pass jets, engines which I do not propose to discuss today.