Still, the army purchased a few aircraft from Boeing as test planes, and some insiders remained convinced that the aircraft was flyable. So a group of test pilots got together and considered what to do. What they decided not to do was almost as interesting as what they actually did. They did not require Model 299 pilots to undergo longer training. It was hard to imagine having more experience and expertise than Major Hill, who had been the air corps' chief of flight testing. Instead, they came up with an ingeniously simple approach: they created a pilot's checklist. Its mere existence indicated how far aeronautics had advanced.

In the early years of flight, getting an aircraft into the air might have been nerve-racking but it was hardly complex. Using a checklist for takeoff would no more have occurred to a pilot than to a driver backing a car out of the garage. But flying this new plane was too complicated to be left to the memory of any one person, however expert. The test pilots made their list simple, brief, and to the point - short enough to fit on an index card, with step-by-step checks for takeoff, flight, landing, and taxiing. It had the kind of stuff that all pilots know to do. They check controls are unlocked - dumb stuff. You wouldn't think it would make that much difference. But with the checklist in hand, the pilots went on to fly the Model 299 a total of 1.8 million miles without one accident. The army ultimately ordered almost thirteen thousand of the aircraft, which it dubbed the B-17. And, because flying the behemoth was now possible, the army gained a decisive air advantage in the Second World War, enabling its devastating bombing campaign across Nazi Germany.