The test pilot who made airplanes safer (by teaching us how to break them better)

Jimmy Doolittle, a daring and gifted pilot, played a crucial role in revolutionizing aircraft testing and making airplanes safer. Prior to his work, aircraft design was largely based on intuition and empirical evidence, with little understanding of aerodynamics or structural integrity. Many pilots had short lifespans, with the U.S. Air Mail Service's life expectancy being just four years and 31 out of the first 40 pilots dying in crashes during the service's first decade.

Doolittle's interest in testing aircraft stemmed from his desire to answer fundamental questions about what planes would face and how they might fail. He began experimenting with in-flight stress testing, creating a regimen that involved flying his Fokker PW-7 fighter through loops, barrel rolls, spins, and other maneuvers while measuring the load factor, or the ratio of a plane's lifting ability to its weight.

During his tests, Doolittle pushed the Fokker to its limits, causing an upper wing to crack at 7.8 g's, which was lower than the manufacturer's claimed 8.5 g's. This discovery led him to produce a report that became a significant milestone in aviation history. Although Doolittle's methods may not have been perfect, his approach of pushing products to their limits and carefully measuring their performance laid the groundwork for modern flight testing.