#315 1935 · Boeing · Aerospace / aviation safetylegibility
After its own best test pilots crashed a plane by forgetting a single step, Boeing didn't train pilots harder — it wrote the steps down.
the problem
an operation has grown too complex for even a skilled, experienced operator to reliably execute from memory alone
background
By 1935, Boeing's Model 299 prototype — four engines, retractable landing gear, controllable-pitch propellers, electric trim and multiple hydraulic systems — was by far the most complex aircraft the US Army Air Corps had ever evaluated, competing for a bomber contract against far simpler biplane designs. Test pilots flying it were among the most experienced aviators in the country, and the assumption going into the competition was that flying it safely was purely a matter of pilot skill and experience: put good enough pilots in the cockpit and the complexity would be managed.
On October 30, 1935, the Model 299 took off at Wright Field, climbed briefly, then stalled and crashed, killing two of the five people aboard. The investigation found the cause wasn't a mechanical failure or bad piloting in the usual sense — the flight crew had simply forgotten to release a newly added elevator control lock before takeoff, one step buried among dozens across systems no earlier aircraft had combined. The Army's initial conclusion was that the Model 299 was 'too much airplane for one man to fly,' threatening to end the program outright.
the move
Instead of accepting that verdict or trying to retrain pilots to simply remember more reliably, a group of Boeing engineers and test pilots concluded the aircraft wasn't too difficult to fly, only too complex to trust to memory — and wrote a short, plain checklist of critical steps for taxi, takeoff, flight and landing, to be read aloud and physically checked off before each phase rather than recalled.
the payoff
Flying with the checklist in hand, the same aircraft type went on to log about 1.8 million accident-free miles across its early production run, and the Army ultimately ordered it into service as the B-17. The checklist became mandatory standard procedure across Boeing's fleet, then all of military aviation, then commercial aviation — the same aircraft whose complexity had nearly killed the program became one of the most produced bombers in history.
what came after
The Model 299 checklist is the acknowledged origin of the modern pre-flight and cockpit checklist used industry-wide in aviation today, and its logic was deliberately carried across into other high-complexity fields decades later — most directly the WHO Surgical Safety Checklist, adapted from aviation practice in 2008 to cut surgical complications by treating operating-room error the same way Boeing treated cockpit error: not a training problem, a memory problem.
filed under
references
- [1]Did you know the pre-flight checklist was first introduced by Boeing following the 1935 crash of the prototype B-17 (then known as the Model 299)?The Aviation Geek Club, 2021theaviationgeekclub.com
- [2]Model 299 CrashNational Museum of the United States Air Force, 2015nationalmuseum.af.mil