Key innovative design features have been introduced to the PT6B Series over the years to further increase its appeal in the market. The PT6B-37A has an automatic fuel control and an electronic power turbine governor with a manual back-up – a unique feature for single engine operations.
The PT6B Series is derived directly from the PT6T-3D power section with an offset output gearbox, including clutch system. The basic engine configuration is exactly the same as that of the PT6T and PT6A turboprop, i.e. a two-shaft configuration consisting of a multi-stage compressor driven by a single-stage compressor turbine and an independent shaft coupling the power turbine to the output shaft through the offset reduction gearbox. In fact, the base engine hot section is very similar to the PT6A-34 airline turboprop, thus continuing the heritage of airline-level dependability in Pratt & Whitney's helicopter engines.