
1) Aircraft propulsion component
Found on
https://www.crosswordclues.com/clue/bypass-duct

A bypass duct is an annular passage that allows some of a turbofan`s airflow to bypass the engine core, or gas generator. If the turbofan is unmixed, the bypass duct will terminate at the bypass nozzle. In mixed turbofans, the bypass duct leads to the cold chute of a forced mixer or cold mixer of an annular mixer. Some bypass ducts are unlined, s....
Found on
http://en.wikipedia.org/wiki/Bypass_duct
No exact match found.