Originally Posted by
Allan38103
The main reason for this engine placement relates to aerodynamics (airflow). Newer engines are more efficient, but they're larger in diameter. In short, they won't fit well on the rear of the fuselage. They are more efficient when located out on the wing where the airflow doesn't interact with the flow on the fuselage and tail.
(This is a simple explanation that doesn't consider things like center of thrust, engines pushing on the body vs. the wings pulling, ground clearance, maintenance, high- vs low-wing, cost, etc)
Tail-mounted engines make fuselage stretches more difficult too, apparently.
Some designs also obstructed air flow to engine and made the a/c more prone to stalling and harder to recover, in certain situations.