I have just finished  a working paper called  NOT FLYING BY THE BOOK: SLOW ADOPTION OF CHECKLISTS AND PROCEDURES IN WW2 AVIATION. It tells how, in 1937 shortly before World War 2,  the American air forces invented a much better way to train new pilots, and to fly complex aircraft and missions. What they invented is now used all over the world, by all licensed pilots and military aviators. But during the war, even American pilots resisted switching to the new way of flying. The only full-speed adopters were the strategic bombing forces attacking Germany and Japan. The US Navy, despite being one of the 1937 inventors, did not fully make the switch until after 1960!

Precise flying was a matter of life or death.