Aircraft system with gas turbine engine powered compressor

An aircraft system, comprising:

• a gas turbine engine including a compressor section, a turbine section, a combustor section and a rotating structure, the combustor section fluidly coupled with and between the compressor section and the turbine section, and the rotating structure including a compressor section rotor within the compressor section and a turbine section rotor within the turbine section;
• a gearbox;
• a first compressor including a first compressor rotor rotatably driven by the rotating structure through the gearbox independent of a second compressor rotor;
• and
• a second compressor including the second compressor rotor rotatably driven by the rotating structure through the gearbox independent of the first compressor rotor;
• wherein the gas turbine engine is configured to power operation of the first compressor and the second compressor at least during aircraft cruise.

A method, comprising:

• providing a system for an aircraft;
• the system including a gas turbine engine, a gearbox, a first compressor, and a second compressor;
• the gas turbine engine including a compressor section, a turbine section, a combustor section and a rotating structure, the combustor section fluidly coupled with and between the compressor section and the turbine section, and the rotating structure including a compressor section rotor within the compressor section and a turbine section rotor within the turbine section, wherein the gas turbine engine is dedicated to powering at least the first compressor;
• the first compressor comprising a first compressor rotor rotatably driven by the rotating structure through the gearbox independent of a second compressor rotor;
• the second compressor comprising the second compressor rotor rotatably driven by the rotating structure through the gearbox independent of the first compressor rotor;
• operating the gas turbine engine to drive rotation of the first compressor rotor through the gearbox at least during cruise of the aircraft.