Where did checklists come from?

  • Published
  • By Col. Timothy P. Schultz
  • Air Combat Command Safety Office
MAXWELL AIR FORCE BASE, Ala. --  In the 1930s, the quality of aircrew performance was improved by a simple, effective form of standardization: the checklist. Like a recipe, a checklist consisted of written, step-by-step procedures that ensured Airmen performed their duties in the correct manner and sequence. Even experienced pilots benefited from this tool.

Consider, for example, the tragic event that convinced the Army Air Corps to institute checklists in aircraft operations. On 30 October 1935, the Air Corps wheeled out the prototype of Boeing's B-17 Flying Fortress at Wright Field, Ohio, for a demonstration flight. The test pilots taxied the bomber onto the runway, pushed the controls for all four engines to full power, and the bomber lumbered forward. As the aircraft continued to gain airspeed and climb away from the ground, the nose began to pitch upward at an unexpected rate. The pilots pushed forward on the control column to lower the nose, but with no effect. With its engines at full power, the bomber entered an alarmingly steep climb and stalled a few hundred feet above the ground. It performed a graceful half-pirouette and pointed straight back to the ground. The nose started to pitch up again as the aircraft gained speed in its downward plummet, and the bomber slammed onto its belly, bursting into flames. Two of the five crewmembers died. The cause: pilot error. The co-pilot, Lieutenant Donald Putt, survived and recounted what happened: "We took off with the controls [elevator and rudder] locked. It was the first airplane in which you could lock the control surfaces from the cockpit. When we taxied out, for some reason we were in a hurry. Those were the days before the checklists" (Putt, 1974). Control locks prevented the bomber's large elevator and rudder from flailing about during high winds on the ground, and Boeing engineers had installed a special lever in the cockpit so the pilot could unlock the controls. The pilot forgot. Both the co-pilot and another pilot standing between them also forgot. Although the crewmembers were highly experienced, they had little time to develop the important habits and procedures necessary for this specific aircraft. The Air Corps applied the hard lesson of this tragedy and ordered the use of checklists during aircraft operation.

The official B-17 flight manual in World War II cautioned pilots that operation of the B-17 was too complex for even experienced pilots to memorize; the checklist, therefore, was the "only sure safeguard" against pilot error, and it was "absolutely essential that the cockpit checklist be used properly by pilot and co-pilot at all times" (U.S Army, no date).

The above excerpt is from:
Schultz, Timothy P. (2007). The Problem with Pilots: How Physicians, Engineers, and Airpower Enthusiasts Redefined Flight. Duke University dissertation.

Also referenced/sourced:
Putt, Donald. L. (1974). Interview by Murray Green. Manuscript Series 33, Box 9, Clark Special Collections Branch, USAFA Library.
U.S. Army. (No date). Pilot Training Manual for the B-17 Flying Fortress, Headquarters Army Air Forces, Office of Flying Safety. Manuscript Series 33, Box 9, Clark Special Collections Branch, USAFA Library.