JT8 Engine - Introduction

The Pratt & Whitney JT8D is a low-bypass turbofan engine, introduced by PW in 1963 with the inaugural flight of the Boeing 727.
The JT8D is an axial-flow turbofan engine incorporating the dual-spool design. There are two coaxially-mounted independent rotating assemblies: one rotating assembly for the low pressure compressor (LPC) which consists of the first six stages of rotating and stator blades, including the first two stages which are for the bypass turbofan, driven by the LPT (consisting of three stages); and a 2nd rotating assembly for the HPC section, which has seven stages. The HPC is driven by the single stage HPT.