Hangar Talk August 2016
Hangar Talk — How checklists changed aviation
ON OCTOBER 30, 1935, at Wright Air Field in Dayton, Ohio, the US Army Air Corps held a flight competition for aircraft manufacturers vying to build its next-generation long-range bomber. It was not supposed to have been much of a competition.
In early evaluations, the Boeing’s gleaming aluminium-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; it could fly faster than previous bombers, and 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 the military historian Phillip Meilinger, was regarded as a mere formality. The Army planned to order at least 65 of the aircraft.
A small crowd of Army brass and manufacturing executives watched as the Model 299 test aircraft taxied on to the runway.
It was sleek and impressive, with a hundred-and-three-foot wingspan and four engines jutting out from the wings, rather than the usual two.
The plane roared down the tarmac, lifted off smoothly, and climbed sharply to three hundred feet. Then it stalled, turned on one wing, and crashed in a fiery explosion. Two of the five crew members died, including the pilot, Major Ployer P. Hill.
An investigation revealed that nothing mechanical had gone wrong. The crash had been due to “pilot error,” the report said.
Substantially more complex than previous aircraft, the new aircraft 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 constantspeed 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 US 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 1,8 million miles without one accident. The Army ultimately ordered almost thirteen thousand of the aircraft, which it dubbed the B-17.................................................To read the full article please subscribe to our E Magazine Here.
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