For an improved and lower part count version, go here

https://kerbalx.com/Kronus_Aerospace/Kronus-PW-JT9D-V2

Engine Description

Details

- Type: Subassembly

• Class: aircraft
• Part Count: 171
• Pure Stock

This craft is a 1:1 replica of the Pratt & Whitney JT9D High-Bypass turbofan. Being the first of the now standard class, it shares attributes of both older and more modern engines. This gives it a rather unique and, in my opinion, cool appearance. This engine was developed specifically to be used on the original Boeing 747, the first wide-bodied airliner, which further adds to its interesting history.

This engine’s design made it much more of a challenge to replicate using stock parts than the others I have tackled thus far. Hence why it is the smallest (in terms of blade diameter) yet has the highest part count. Its smaller size also meant that including a stock mechanism for it to rotate was simple not viable, and its inclusion would have only increased the part count.

Like with my other engines, it requires an exterior source of intake air. Though any craft large enough to warrant its use should have plenty of room to hide a few nacelles or precoolers.