system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: Why do small jet aircraft, like regional jets and private jets, have engines on the rear, but larger jet planes have engines on the wings?
gpt
Typically, the wings on a smaller plane are closer to the ground.  The plane isn't as thick and long thin landing gear are too easy to break or too heavy to lift.

There isn't enough space under the wing for the engine, and safe clearance against the runway.  Mounting them to the body works as well, and the longer fuel pipes don't add much weight.