Origins of the Checklist
On October 30, 1935, the U.S. Army Air Corps held a flight competition for airplane manufacturers vying to build its next-generation long-range bomber. It wasn't supposed to be much of a competition; in early evaluations, the Boeing Corporation's gleaming aluminum-alloy Model 299 had trounced the designs of Martin and Douglas.
Boeing's plane could carry five times as many bombs as the Army had requested, could fly faster than previous bombers, and travel almost twice as far. A Seattle newspaperman who had glimpsed the plane called it the "flying fortress," and the name stuck. The flight "competition," according to military historian Phillip Meilinger, was regarded as a mere formality. The Army planned to order at least 65 of them.
A small crowd of Army brass and manufacturing executives watched as the Model 299 test plane taxied onto the runway. It was sleek and impressive, with a 103-foot wingspan and four engines jutting out from the wings rather than the usual two. The plane roared down the runway, lifted off smoothly, and climbed sharply to 300 feet AGL.
Then it stalled, turned on one wing, and crashed in a fiery explosion, killing two of the five crew members, including the pilot, Major Ployer P. Hillónamesake of Hill Air Force Base, Ogden, Utah.
An investigation revealed that the crash was due to "pilot error." Substantially more complex than previous aircraft, the new plane required the pilot to attend to the four engines, a retractable landing gear, new wing flaps, electric trim tabs that needed adjustment to maintain control at different airspeeds, and constant-speed propellers whose pitch had to be regulated with hydraulic controls, among other features.
While doing all this, Hill had forgotten to release a new locking mechanism on the elevator and rudder controls. The Boeing model was deemed, as a newspaper put it, "too much airplane for one man to fly." The Army Air Corps declared Douglas' smaller design the winner. Boeing nearly went bankrupt.
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. They could have required Model 299 pilots to undergo more training. But it was hard to imagine having more experience and expertise than Major Hill, who had been the U.S. Army Air Corps' chief of flight testing. Instead, they came up with an ingeniously simple approach: They created a pilot's checklist, with step-by-step checks for takeoff, flight, landing, and taxiing. 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 this new plane was too complicated to be left to the memory of any pilot, however expert.
With the checklist in hand, the pilots went on to fly the Model 299 a total of 18 million miles without one accident. The Army ultimately ordered almost 13,000 B-17s, and because flying the behemoth was now possible, the Army gained a decisive air advantage in World War II, enabling its devastating bombing campaign across Nazi Germany.
Oliver R. Crawford