Determines in which major modules the defect is located such as (1) the accessory gear box module that is driven through gearing by the compressor rotor, the hydro-mechanical unit (HMU), oil pump, starter and hydraulic pump are mounted on and driven by the accessory gearbox module); (2) the forward engine module which includes the inlet housing assembly, low pressure compression assembly, diffuser, high pressure nozzle, combustor assembly and turbine assembly and turbine assemblies; (3) the rear engine module which includes the low pressure nozzle and turbine assembly, recuperator assembly and power turbine and (4) reduction gear box with power gears. Possess a thorough knowledge of the mechanical makeup, operation, and working relationships of heavy duty systems, assemblies, subassemblies, and parts, including such major systems as diesel, multi fuel, and gasoline engines, including supercharged and turbocharged engines; turbine engines; automatic and manual transmissions and gear reduction systems, including those with torque converters, planetary gears, and power take offs; drive line assemblies including differentials, power dividers, and dual speed axles; electrical and electronic systems, and wiring and lighting systems; carburetor and fuel injection systems; and emission control systems.