Propulsion system for a vertical and short takeoff and landing aircraft

A propulsion system for an aircraft having a fuselage and right and left wings with right and left engine nacelles mounted beneath each wing, respectively, the propulsion system comprising right and left turbo-fan engines comprising:

• a fan section having a variable pitch fan;
• a compressor section;
• a combustion section;
• a turbine section, said turbine section having a low-pressure turbine portion coupled to and driving said fan section and a high-pressure turbine portion coupled to and driving said compressor section, said engine having a selectable operating point wherein a portion of the power generatable by said low-pressure turbine at a selected operating power setting is extracted to drive said fan section;
• a turbine outlet duct for directing said turbine section exhaust gases;
• end
• a first angular shaped nozzle section co-incident with said turbine outlet duct for directing exhaust from said fan section;
• a second nozzle section mounted to said first angular shaped nozzle section between said fan section and said compressor section;
• and
• means to shift said selectable operating point of said engine to a second operating point at the selected power setting increasing the power extracted by said low-pressure turbine portion of said turbine section;
• such that power extracted by said low-pressure turbine portion and applied to said fan section can be increased without changing the selected power setting, and the pitch of the blades of said variable pitch fan section can be increased to absorb said increased power.