Yet another good question. Perfect typing was rare -- I was pretty good with a typewriter, and yet the eraser was my friend...
When I came into the AF in 1975...the best typists...worked at wing headquarters and were highly valued. If you could 40 words a minute with almost errors...you were highly sought.
How many Commanders in 1975 could type 40 words a minute? In the entire Air Force...including Guard and Reserve...less than 20...and none...repeat...none...were pilots (trust me...I worked around these guys and can attest to their true lack of admin skills). The only Commanders who could type...were English majors or did staff work at the Pentagon.