Which of the following is NOT a main section of a non-modular turbine engine?

• A. Fan section
• B. Compressor section
• C. Gearbox section
• D. Accessory section

Answer: (C)

In a non-modular turbine engine, the main sections are defined by the primary gas-path pieces: the fan, the compressor, the combustor, and the turbine. The gearbox is a mechanical drive that powers accessories and does not form part of the core gas-path stages. It sits with the accessory drive system, which handles pumps, starters, and other hardware, but it isn’t a main engine section. So the gearbox section isn’t considered a main section of the engine.