When US air force pilots were struggling to control their planes in the late 1940s, officials were mystified. With 17 crashes recorded in a single day, it was happening too often to be pilot error but engineers frequently found no technical or mechanical defects. Attention finally turned to the physical design of cockpits back in the mid-1920s and whether the size of pilots had changed.
Using data from more than 4000 pilots, a researcher set out to determine how many pilots were average size. Using the 10 most relevant physical dimensions — including chest circumference, height and sleeve length — he plotted the size of this “average” pilot. When he posted his findings, the laboratory was stunned to find that not one single pilot fit the average on all of the dimensions. It turned out designing a cockpit to fit everybody resulted in designing it to fit nobody.