use pylons to mount the engines on jetliners

 Why do we use pylons to mount the engines on jetliners???✈️

-The first jet airliner (de Havilland Comet) had its engines inside the wings .. which had huge advantages in terms of aerodynamics

but there are also disadvantages - mostly safety and economically - which are why engines on pylons became prevalent:

1. If something bad happens to your engine (fire, uncontained turbine or fan failure) the engine is some distance away from the wing spar structure, hydraulics and fuel tanks - this makes it a lot less likely that the engine will damage those fatally than when the engine is right beside those systems

2. On a pylon the engine is much easier to reach from all sides and thus much easier and faster cheaper) to maintain - an engine inside the wing is a lot harder to reach and service, because there are fewer and smaller service doors (on a pylon basically the whole engine cover can be opened

3. Engines on pylons are also easier to change if newer, larger engines become available. The Comet was basically limited to a certain engine diameter; increasing that diameter basically means a complete redesign of the wing structure (VERY expensive). The Boeing 707 had its engines on pylons and was re-engined with new, larger diameter engines at least twice during its manufacturing life, because changing the engine did not mean a redesign of the wing and was therefore much cheaper to do.

© Airbus and Boeing