The question says it all. As I recall, part of the plot concerns replacing semi-intelligent military aircraft with human-piloted military aircraft, with much greater performance realization.
"The Feeling of Power", a short story by Isaac Asimov, first published in If, February 1958, available at the Internet Archive. It's about a man in the future who rediscovers the art of calculating without a computer, using pencil and paper, and the military applications of his discovery.
Wikipedia plot summary:
In the distant future, humans live in a computer-aided society and have forgotten the fundamentals of mathematics, including even the rudimentary skill of counting.
The Terrestrial Federation is at war with Deneb, and the war is conducted by long-range weapons controlled by computers which are expensive and hard to replace. Myron Aub, a low grade Technician, discovers how to reverse-engineer the principles of pencil-and-paper arithmetic from computers—a development which is later dubbed "Graphitics". The discovery is appropriated by the military establishment, who use it to re-invent their understanding of mathematics. They also plan to replace their computer-operated ships with lower cost, more expendable (in their opinion) manned ships to continue the war.
Aub is so upset by the appropriation of his discovery for military purposes that he commits suicide. As Aub's funeral proceeds, his supervisor realizes that even with Aub dead, the advancement of Graphitics is unstoppable. He executes simple multiplications in his mind without help from any machine, which gives him a great feeling of power.
Excerpt from the story:
The general was saying, "Our goal is a simple one, gentlemen; the replacement of the computer. A ship that can navigate space without a computer on board can be constructed in one-fifth the time and at one-tenth the expense of a computer-laden ship. We could build fleets five times, ten times as great as Deneb could if we could but eliminate the computer.
"And I see something even beyond this. It may be fantastic now; a mere dream; but in the future I see the manned missile!"