Which is NOT one of the three main engine sections?

The fuel supply section is not considered one of the three main engine sections of a gas turbine engine. The main sections of a gas turbine engine typically include the gas generation section, which encompasses components such as the compressor, combustion chamber, and turbine; the power turbine section, which is responsible for extracting energy from the hot gases produced during combustion; and the accessory compartment, which contains various engine accessories, not directly involved in the propulsion process but essential for engine operation, such as fuel pumps, lubrication systems, and electrical generators.

In a typical gas turbine engine setup, fuel supply is certainly crucial, but it is integrated into the gas generation section as part of the overall engine architecture rather than standing alone as a distinct main section. This distinction clarifies why the fuel supply section does not align with the core structural breakdown of the engine.