Pratt & Whitney PT6A-6 is the first production PT6 engine, shipped in December 1963 to Beech Aircraft for the Beech 87 and early King Air program. The PT6A architecture is a two-shaft turboprop with a multi-stage compressor, single-stage compressor turbine, independent free power turbine, and epicyclic concentric reduction gearbox. This historical record preserves the exact -6 identity; no model-specific installation or numeric rating is asserted here.