Aircraft powerplant with boosted gas turbine engine

An aircraft system, comprising:

• a first gas turbine engine comprising a first compressor section, a first combustor section, a first turbine section and a first flowpath extending sequentially through the first compressor section, the first combustor section and the first turbine section, the combustor section comprising a combustor;
• an un-ducted rotor configured to be rotatably driven by the first gas turbine engine, the un-ducted rotor comprising an array of rotor blades;
• a second gas turbine engine comprising a second inlet, a second exhaust, a second compressor section, a second combustor section, a second turbine section and a second flowpath fluidly coupled with and between the second inlet and the second exhaust, the second flowpath extending sequentially through the second compressor section, the second combustor section and the second turbine section, the second inlet fluidly coupled with the first flowpath upstream of the combustor, and the second exhaust fluidly coupled with the first flowpath;
• an electric generator configured to be rotatably driven by the second gas turbine engine;
• and
• an electric component configured to receive electricity generated by the electric generator, the electric component located outside of the first gas turbine engine.

An aircraft system, comprising:

• a first gas turbine engine comprising a first compressor section, a first combustor section, a first turbine section, a first rotating structure and a first flowpath extending sequentially through the first compressor section, the first combustor section and the first turbine section, the combustor section comprising a combustor, and the first rotating structure comprising a first turbine rotor within the first turbine section;
• an un-ducted rotor configured to be rotatably driven by the first rotating structure, the un-ducted rotor comprising an array of rotor blades;
• a second gas turbine engine comprising an inlet, an exhaust, a second compressor section, a second combustor section, a second turbine section, a second rotating structure and a second flowpath fluidly coupled with and between the inlet and the exhaust, the second flowpath extending sequentially through the second compressor section, the second combustor section and the second turbine section, the inlet configured to bleed air out of the first flowpath upstream of the combustor, the exhaust configured to direct exhaust from the second gas turbine engine into the first flowpath, and the second rotating structure comprising a second turbine rotor within the second turbine section;
• an electric generator configured to be rotatably driven by the second rotating structure;
• and
• an electric component configured to receive electricity generated by the electric generator, the electric component independent of the first gas turbine engine.