What are the advantages and disadvantages of tail wheels that cause modern airplanes to not use them?
A tailwheel is a good choice for operation on unprepared surfaces with aircraft that have low wing loading and need to be as light as possible. Two main wheels and a small tail wheel weigh less and cause less drag than a tricycle gear, especially if they cannot be retracted. On the Bo-209 Monsun only the nose gear was made retractable because, being positioned right behind the prop, it caused 40% of gear drag all by itself.

On the other hand, high wing loading aircraft with their high landing speed would need very long landing runs due to their inability to brake hard. A rejected take-off close to the decision speed would be impossible without crashing through the airfield perimeter. Braking too hard with a tailwheel configuration will cause a headstand.

To summarise the reasons given in this answer:


A tricycle gear offers better visibility on the ground.
A tricycle gear allows full brake application.
A tricycle gear makes loading and unloading easier because the fuselage is horizontal.
A tricycle gear has less drag during the initial stage of a take-off run.


Cessna simply shifted priorities between the 140 and the 150.